Copper-Catalyzed N-Arylation of ... - ACS Publications

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Cite This: J. Org. Chem. 2017, 82, 11752-11764

Copper-Catalyzed N‑Arylation of Nitroenamines with Diaryliodonium Salts Klára Aradi,† Á dám Mészáros,‡ Balázs L. Tóth,‡ Zoltán Vincze,*,† and Zoltán Novák*,‡ †

Department of Chemistry, University of Veterinary Medicine, István utca 2, H-1078 Budapest, Hungary MTA-ELTE “Lendület” Catalysis and Organic Synthesis Research Group, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter stny. 1/a H-1117 Budapest, Hungary

‡

S Supporting Information *

ABSTRACT: A novel synthetic methodology was developed for the N-arylation of nitroenamine derivatives utilizing diaryliodonium triflates and copper(I) chloride as a catalyst. The procedure enables the easy aryl transfer from the hypervalent species under mild catalytic conditions with unusual heteroatom preference and high efficiency.

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addition13 or substitution,14 coupling reaction,15 Diels−Alder reaction,16 and reductions.17 Beside the synthetic aspects, β-nitroenamines also exhibit pharmaceutical activity18 as they are useful building blocks of biologically active compounds, such as the histamine H2receptor antagonist Ranitidine and Nizatidine. Moreover, some β-nitroenamine derivatives were determined to show insecticidal activity,19 such as imidacloprid, nytenpyram, or different halonicotinylimidazolidine and hexahydroimidazo[1,2-a]pyridine derivatives (Scheme 1).

INTRODUCTION Construction of aromatic and heteroaromatic molecules with the utilization of copper catalyst is an important field of synthetic organic chemistry.1 Transformations including diaryliodonium salts2 have recently become an important and widespread research field as these reactants have been recognized as efficient electrophilic arylation reagents with a wide range of nucleophiles under both metal-free and metalcatalyzed conditions. Thanks to this fact, with the utilization of diaryliodonium compounds several transition-metal-free arylation processes were developed in the last decades for the functionalization of carbon,3 oxygen,4 nitrogen,5 and sulfur6 nucleophiles. Beside the transition metal free transformations, the comprehensive employment of diaryliodonium salts was described in copper-catalyzed reactions, such as C−H functionalizations7 and arylation-cyclization processes8 for the construction of diverse heterocyclic skeletons from electron rich substrates, such as alkenes, alkynes, and nitriles. The importance of the activation of carbon−carbon multiple bond in the presence of copper catalysts and electrophile reagents, such as diaryliodonium salts, is unquestionable as it enables variable functionalization via the introduction of aryl or heteroaryl moiety. We aimed to extend this methodology to other compounds having importance both from biologic and synthetic aspects. Therefore, we focused on β-nitroenamines, known as push−pull alkenes9 with the electron donating amino group and the electron withdrawing nitro group. Due to their diverse structure, β-nitroenamines are important building blocks in organic chemistry as they can serve as starting materials for the synthesis of many fused heterocyclic compounds.10 The versatile reactivity of β-nitroenamines has been demonstrated through several transformations, such as Michael additions,11 1,3-dipolar cycloaddition,12 nucleophilic © 2017 American Chemical Society

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RESULTS AND DISCUSSION

Due to the widespread applications of β-nitroenamines in the fields of organic chemistry and biology, the study of the reactivity of this compound class could contribute to the development of novel transformations. In this context, the reactivity of β-nitroenamines via carbon−carbon double bond functionalization is well-documented11−17 and has preferential reactivity over the NH moiety in these types of reactions. The strong nucleophilic character of β-carbon enables the versatile functionalization of the carbon−carbon double bond in the presence of different electrophiles. Since diaryliodonium compounds serve as electrophilic arylation reagents, we aimed to explore the reactivity pattern of this ambident substrate toward the catalytically active highly electrophilic species generated from diaryliodonium salts and copper(I) catalyst (Scheme 2). Special Issue: Hypervalent Iodine Reagents Received: June 27, 2017 Published: August 30, 2017 11752

DOI: 10.1021/acs.joc.7b01591 J. Org. Chem. 2017, 82, 11752−11764

Article

The Journal of Organic Chemistry Scheme 1. Synthetical and Biological Aspects of β-Nitroenamines

Scheme 2. C-Arylation of β-Nitroenamines with Diaryliodonium Salt

inorganic and organic bases in the reaction revealed that N,Ndiisopropylethylamine (DIPEA) and triethylamine (TEA) are suitable for the efficient reaction (entries 7−8), while the employment of lithium carbonate and potassium carbonate afforded moderate yields (entries 9−10). No reaction was observed in the presence of potassium tert-butoxide and cesium carbonate (entries 11−12). When the activity of copper catalysts was studied we found that CuCl, CuBr, CuI, and (CH3CCN)4Cu(OTf) are suitable for the transformation (entries 7, 13−15). In the case of CuSO4 and Cu(OTf)2 85 and 89% conversions were reached (entries 16−17), while the reaction time was longer, when Cu and Cu(acac)2 were utilized as copper sources (entries 18−19). Additionally, the arylation reaction did not occur without catalyst (entry 20). The optimal base-catalyst amount was also examined and was found that the amount of CuCl can be reduced to 2.5 mol% by increasing the amount of base to 2 equiv, while 99% conversion was reached under this reaction conditions (entry 21). After finding the optimal reaction conditions, we focused to the study of the substrate scope of the developed method. (Z)N-(2-nitro-1-phenylvinyl)aniline (1a) was reacted with phenylmesityliodonium triflate (2a) using 2 equiv of DIPEA base and 2.5 mol % CuCl catalyst in DMF at 50 °C, and 3aa was obtained in 66% yield as 1:1 mixture of E- and Z-isomers (Scheme 3). In the presence of methyl group in the para position of the phenyl ring of the salt, the desired product (3ab) was isolated in 78% yield (as 7:3 mixture of E- and Zisomers). Attempted reactions with diaryliodonium salts

To achieve the arylation studies, we synthesized Z(nitroarylvinyl)anilines as model substrates from the appropriate nitroketones and anilines. In the corresponding nitroenamine derivatives the Z conformation was proved by the high value of the chemical shift belonging to the NH group in 1H NMR spectra. The molecule is stabilized by a chelate complex formed between the hydrogen of the NH group and the oxygen of the NO2 group.14,20 To optimize the reaction conditions, we chose (Z)-N-(2nitro-1-phenylvinyl)aniline (1a) as nitroenamine substrate and phenylmesityliodonium triflate (2a) as the aryl source. Their reaction was carried out at 50 °C for 3 h in the presence of various copper catalysts and bases.21 Contrary to the general reactivity of the nitroenamines, instead of the C-arylated product the N-arylated compound was isolated from the reaction mixture (based on 1H NMR measurements). The preferential reactivity of N-arylation over the C-functionalization with the employment of diaryliodonium salts was recently demonstrated on 2-pyridones22 and phenylanalinamides23 in toluene and dioxane solvents. In our case, the study of the influence of the selected solvent on the transformation showed that the arylation reaction is slower in methanol (MeOH), 1,2dichloro ethane (DCE), and toluene (67−82% conversion), and provides 86, 88, and 92% conversion in diethyl ether (Et2O), tetrahydrofuran (THF), and ethyl acetate (EtOAc), respectively (Table 1, entries 1−6). In contrast, 99% conversion was reached in 3 h when the reaction was conducted in dimethylformamide (DMF, entry 7). Investigation of different 11753


Article

The Journal of Organic Chemistry Table 1. Optimization of Reaction Conditionsa

entry

base

catalyst

solvent

conversionb (%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20c 21d

DIPEA DIPEA DIPEA DIPEA DIPEA DIPEA DIPEA TEA Li2CO3 K2CO3 KOtBu Cs2CO3 DIPEA DIPEA DIPEA DIPEA DIPEA DIPEA DIPEA DIPEA DIPEA

CuCl CuCl CuCl CuCl CuCl CuCl CuCl CuCl CuCl CuCl CuCl CuCl CuBr CuI (CH3CN)4Cu(OTf) CuSO4 Cu(OTf)2 Cu Cu(acac)2

MeOH DCE PhMe Et2O THF EtOAc DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF DMF

67 78 82 86 88 92 99 96 50 74 0 0 94 98 94 85 89 34 51 0 99

CuCl

hindered isopropyl group on of the phenyl group of the diaryliodonium salt also allowed the formation of the desired product (3af), but only in 16% yield. The meta-bromo phenylation underwent in this transformation, providing the products 3hg in 24% yield. The heteroarylation is feasible by the utilization of mesityl (mpiridyl) iodonoium salt. Herein, we implemented the introduction of 3-pyridyl group to nitrogen center and the desired products (3fh) formed. In continuation of the study of the substrate scope, we examined the reactivity of additional nitroenamine substrates in the arylation reaction. We synthesized several nitroenamines (1d−1o) equipped with different substituents both on the aryl groups of the aniline and the nitroolefin moiety and we reacted them with phenylmesityliodonium triflate (Scheme 4). When the aryl group attached to the nitrogen of the nitroenamine (1d) was equipped with two electron donating methyl groups, the appropriate product (3da) was isolated (as 5:3 mixture of E- and Z-isomers) in high yield (88%). Utilizing the nitroenamine substrate (1f) bearing halogens on the aryl group of the aniline moiety in the arylation reaction, we were able to prepare product 3fa (in 1:1 ratio of E- and Z-isomers) in moderate yield (51%). When we changed the electronic properties of the nitroenamine using substrate 1g equipped with the electron withdrawing nitro group on the aniline part; the arylation reaction also occurred and led to product 3ga in 57% yield. Then, we examined the applicability of nitroenamine substrates (1h and 1i) bearing electron withdrawing nitro group on the phenyl ring of the nitroolefin and prepared from electronically different anilines in the arylation procedure. When the arylation was performed on nitroenamine 1h containing aryl group equipped with electron donating methyl groups, we could isolate product 3ha in 62% yield. The presence of halogen on the aryl group of the aniline moiety was also tolerated and nitroenamine 1i was transformed to the appropriate N-arylated compound (3ia) in moderate yield (42%). Next, we investigated the reactivity of nitroenamines (1j−1o) prepared from the chloro-substituted nitroketones and from the electronically different anilines. The presence of electron donating methyl groups in the aniline did not have negative impact on the reaction and nitroenamine 1j afforded the desired product (3ja) in good yield (74%). We were also able to isolate the corresponding N-arylated compound (3ka) in 61% yield (as 1:1 mixture of E- and Zisomers) from the substrate 1k equipped with chloro substituents on both aryl groups of the nitroenamine. The utilization of nitroenamine derivative (1l) bearing electron withdrawing nitro group in the aniline provided the appropriate product (3la) in 57% yield. Finally, the arylation procedure was also performed with substrates (1m−1o) equipped with electron rich tolyl group attached to the double bond of the nitroolefin. The reaction of (Z)-N-(2-nitro-1-(p-tolyl)vinyl)-Nphenylaniline (1m) with phenylmesityliodonium triflate provided the desired N-arylated compound (3ma) in 48% yield (as 1:1 mixture of E- and Z-isomers). When we employed substrate 1n substituted with methyl groups on both aryl groups of the nitroenamine, the corresponding product (3na) was isolated in 82% yield. The presence of halogen on the aryl group of the aniline was also tolerated and nitroenamine 1o afforded the desired product (3oa) in 58% yield. The possible mechanism of this unique N-arylation supposedly starts with the reaction of the copper(I) catalyst and the diaryliodonium salt. Based on the mechanistic

a

(Z)-N-(2-nitro-1-phenylvinyl)aniline (0.125 mmol), phenylmesityliodonium triflate (0.175 mmol, 1.50 equiv), base (0.175 mmol, 1.50 equiv), copper catalyst (0.013 mmol, 0.10 equiv); solvent (500 μL), N2, 50 °C, 3 h. bConversion values were determined by GC-FID analysis. c25 °C. d2.5 mol% CuCl and 2 equiv base.

bearing halogens (Br, F) in para position, compound 1a was transformed to the desired N-arylated products (3ac and 3ad) in 58 and 72% yield, respectively (in 1:1 and 6:4 ratio of E- and Z-isomers). Additionally, the examination of the applicability of different arylmesityliodonium salts was also demonstrated on (Z)-N-(2-nitro-1-(4-nitrophenyl)vinyl)aniline (1b) as a more electron deficient substrate. When phenylmesityliodonium triflate (2a) was applied in the arylation procedure, the desired product (3ba) was obtained in 79% (as 7:3 mixture of E- and Z-isomers). The reaction of diaryliodonium salt bearing methyl substituent in the para position of the phenyl group gave the corresponding product (3bb) in 71% yield. Nitroenamine substrate 1b was converted to the corresponding N-arylated derivatives (3bc and 3 bd) in 47% and 69% yields with arylmesityliodonium salts having halogens such as Br or F on the aryl ring, Reaction of iodonium species containing COOEt group on its aryl ring in the para position and nitroenamine gave the appropriate product 3be in 54% yield (as 6:5 mixture of E- and Z-isomers). The reaction of the nitroenamine substrate 1c containing halogen in the para position of the phenyl ring of the nitroolefin moiety with phenylmesityliodonium triflate, product 3ca was isolated in 70% yield (in 14:11 ratio of E- and Z-isomers), while in the case of diaryliodonium salt bearing a para methyl or bromo substituent, the desired Narylated compounds (3cb and 3cc) were obtained (as 2:1 mixture of E- and Z-isomers) in good and moderate yields (80 and 55%), respectively. The presence of more sterically 11754


Article

The Journal of Organic Chemistry Scheme 3. Synthesis of N-Arylated Nitroenamines (3aa−fh)a

a (Z)-N-(2-nitro-1-arylvinyl)aniline (0.5 mmol, 1.0 equiv), arylmesityliodonium triflate (0.8 mmol, 1.5 equiv), DIPEA (0.1 mmol, 2.0 equiv), CuCl (0.013 mmol, 0.03 equiv); DMF (2.0 mL), N2, 50 °C, % yield. bRatio of E and Z isomers; (n.d.): ratio could not be determined due to the overlaps of peaks in the NMR spectra. cDIPEA (0.8 mmol, 1.5 equiv), CuCl (0.05 mmol, 0.10 equiv). d24 h 50 °C, and 24 h 110 °C. eDIPEA (1.5 mmol, 3 equiv).

equiv of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) as radical trapping reagent. The reaction gave the same result (80% yield) which excludes a radical pathway.

proposals of similar transformations the interaction of the catalyst and the iodonium salt results the formation of a highly electrophilic Ph−Cu(III) species (4).7a−c,8,24 We suppose the formation of complex 5 after the deprotonation of nitrone form of 1a, which yields the product (3a) as a mixture of E- and Zisomers via a reductive elimination step (Scheme 5).25 Without the stabilization effect of hydrogen bond and because of the low barrier of the rotation around C1−C2 in these compounds, the presence of E- and Z-configurational isomers in the products (3a) is well interpreted and discussed in the literature.26 The preparation of 3cb products was repeated in the presence of 3

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CONCLUSION Summarizing our results, we developed a novel copper catalyzed N-arylation of nitroenamines with the employment of diaryliodonium salts. In contrast to the known reactivity of this push−pull system toward electrophiles, we found an unexpected reactivity of nitroenamine substrates. Instead of the CC bond functionalization, N-arylation reaction occurred in 11755


Article

The Journal of Organic Chemistry Scheme 4. Synthesis of N-Phenylated Nitroenamines (3da−oa)a

a

(Z)-N-(2-nitro-1-arylvinyl)aniline (0.5 mmol, 1.0 equiv), arylmesityliodonium triflate (0.8 mmol, 1.5 equiv), DIPEA (0.1 mmol, 2.0 equiv), CuCl (0.013 mmol, 0.03 equiv); DMF (2.0 mL), N2, 50 °C, yields. bRatio of E and Z isomers. cDIPEA (0.8 mmol, 1.5 equiv), CuCl (0.05 mmol, 0.10 equiv).

Scheme 5. Proposed Mechanism for the Nitroenamine 1a Arylation

their reaction with diaryliodonium salts under the catalytic conditions. The transformation ensures the access of nitroen-

amine derivatives substituted with versatile functional groups on the basic frame. 11756


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The Journal of Organic Chemistry

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2H). 13C{1H} NMR (400 MHz, DMSO-d6) δ 188.4, 134.8, 133.4, 129.1, 128.4, 82.8. IR νmax/cm−1 (solid): 2964, 1692, 1552, 1333, 1228, 1202, 760, 685, 662. 2-Nitro-1-(4-nitrophenyl)ethan-1-one (1b″).31 Prepared according to the general procedure A from 2-nitro-1-(4-nitrophenyl)ethan-1-ol (17.3 g, 81.4 mmol). White crystalline solid (7.18 g, 34.2 mmol, 42%). Mp 149−150 °C; Rf = 0.36 (cyclohexane−ethyl acetate, 5:2). 1H NMR (400 MHz, DMSO-d6): δ 8.39 (d, J = 8.4 Hz, 2H), 8.12 (d, J = 8.4 Hz, 2H), 6.61 (s, 2H); 13C{1H} NMR (400 MHz, DMSO-d6): δ 188.3, 151.2, 138.5, 130.4, 124.5, 83.4. IR νmax/cm−1 (solid): 2926, 1705, 1565, 1525, 1322, 1219, 1204, 859, 749, 738, 684, 673. 2-Nitro-1-(4-chlorophenyl)ethan-1-one (1c″).30 Prepared according to the general procedure A from 2-nitro-1-(4-chlorophenyl)ethan1-ol (16.4 g, 81.4 mmol). White crystalline solid (7.61 g, 38.3 mmol, 47%). Mp 144−145 °C Rf = 0.42 (cyclohexane−ethyl acetate, 5:2). 1H NMR (400 MHz, DMSO-d6): δ 7.94 (d, J = 8.4 Hz, 2H), 7.68 (d, J = 8.8 Hz, 2H), 6.53 (s, 2H); 13C{1H} NMR (400 MHz, DMSO-d6): δ 188.0, 140.3, 132.6, 130.8, 129.7, 83.2. IR νmax/cm−1 (solid): 2964, 1694, 1591, 1556, 1404, 1389, 1329, 1200, 836, 823. 2-Nitro-1-(3-nitrophenyl)ethan-1-one (1d″).32 Prepared according to the general procedure A from 2-nitro-1-(3-nitrophenyl)ethan-1-ol (17.3 g, 81.4 mmol). Drab crystalline solid (6.67 g, 31.7 mmol, 39%). Mp 94−95 °C; Rf = 0.42 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 8.70 (d, J = 12.1 Hz, 1H), 8.62−8.37 (m 1H), 8.52−8.37 (m, 1H), 8.34−8.08 (m, 1H), 7.88−7.66 (m, 1H), 5.99 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 184.2, 134.7, 133.8, 132.2, 130.9, 129.3, 123.2, 81.0. IR νmax/cm−1 (solid): 2926, 1706, 1558, 1529, 1353, 1222, 812, 733, 671. 2-Nitro-1-(p-tolyl)ethan-1-one (1e″).30 Prepared according to the general procedure B from 2-nitro-1-(p-tolyl)ethan-1-ol (14.7 g, 81.4 mmol). Purification of the crude product by column chromatography on silica gel afforded the product as a drab solid (4.95 g, 27.7 mmol, 34%). Rf = 0.54 (cyclohexane−ethyl acetate, 7:3). 1H NMR (300 MHz, CDCl3) δ 7.75 (dd, J = 8.9 Hz, 2H), 7.33 (d, J = 7.8 Hz, 2H), 5.87 (s, 2H), 2.45 (s, 3H). 13C{1H} NMR (75 MHz, CDCl3) δ 185.4, 146.6, 131.3, 130.6, 130.2, 130.1, 128.6, 127.11, 81.4, 22.0. IR νmax/ cm−1 (solid): 2926, 1689, 1554, 1330, 1234, 1184, 814, 695. General Procedure 3 for the Synthesis of (Z)-N-(2-Nitro-1arylvinyl)anilines. (Z)-N-(2-Nitro-1-arylvinyl)anilines were synthesized according to the modified procedure of Zhao.20 A mixture of 2nitro-1-phenylethan-1-one (793 mg, 4.80 mmol), aniline (894 mg, 9.60 mmol, 877 μL) and acetic acid (600 μL) were stirred at 80 °C under nitrogen atmosphere until TLC indicated the total consumption of the ketone. The treatment of the reaction mixture (Method A or B) provided the appropriate products as crystalline solids. Method A. Diisopropyl ether was added to the reaction mixture and the resulted crystals were filtered, washed with diisopropyl ether, and dried. If it was necessary, the product was recrystallized. Method B. The reaction mixture was evaporated and the crude residue was purified by column chromatography. (Z)-N-(2-Nitro-1-phenylvinyl)aniline (1a).20 Prepared according to the general procedure A from 2-nitro-1-phenylethan-1-one and aniline. The product was obtained as a yellow crystalline solid (830 mg, 3.46 mmol, 72%). Mp 125−126 °C; Rf = 0.38 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 11.52 (s, 1H), 7.49−7.41 (m, 1H), 7.40−7.27 (m, 4H), 7.20 (t, J = 7.4 Hz, 2H), 7.15−7.07 (m, 1H), 6.84 (d, J = 7.6 Hz, 2H), 6.79 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 155.7, 137.6, 131.6, 130.9, 129.1, 129.0, 128.6, 126.0, 124.0, 114.3. IR νmax/cm−1 (solid): 2919, 1593, 1564, 1480, 1450, 1359, 1274, 1190, 1176, 1156, 1111, 988, 766, 752, 698. (Z)-N-(2-Nitro-1-(4-nitrophenyl)vinyl)aniline (1b).33 Prepared according to the general procedure A from 2-nitro-1-(4-nitrophenyl)ethan-1-one (1.01 g, 4.80 mmol) and aniline. The product was obtained as a yellow crystalline solid (1.01 g, 3.55 mmol, 74%). Mp 178−179 °C; Rf = 0.54 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 11.28 (s, 1H), 8.21−8.14 (m, 2H), 7.55−7.45 (m, 2H), 7.24−7.09 (m, 3H), 6.82 (d, J = 7.8 Hz, 2H), 6.73 (s, 1H); 13 C{1H} NMR (300 MHz, CDCl3) δ 153.1, 149.2, 138.3, 137.2, 130.1, 129.7, 126.8, 124.5, 124.3, 114.9; IR νmax/cm−1 (solid): 2917, 1577, 1520, 1482, 1348, 1279, 1190, 1111, 853, 757, 707.

EXPERIMENTAL SECTION

General Methods. Arylation reactions of substrates 1a−1o with the appropriate iodonium salt (2a−2i) were performed under nitrogen atmosphere. All solvents used were distilled using standard methods. meta-Chloroperbenzoic acid (m-CPBA) was dried under high vacuum at room temperature and was stored under argon. Unless otherwise noted, all reagents were ordered and used without further purification. 1 H NMR and 13C NMR spectra were recorded at 300, 250 and 75, 62.5 MHz using CDCl3 or DMSO-d6 as solvent. Chemical shifts are given in ppm relative to TMS for CDCl3, or the residual solvent peak of DMSO as internal standards. Coupling constants (J) are reported in hertz (Hz). Infrared spectra were recorded on a single-reflection diamond ATR spectrometer as solids or thin films. In the IR spectra, only the strongest/structurally most important peaks (ν, cm−1) are listed. HRMS data for new compounds were obtained using a Q-TQF high-resolution mass spectrometer equipped with an electrospray ion source. The measured melting points are uncorrected. General Procedure 1 for the Synthesis of 2-Nitro-1arylethane-1-ols. 2-Nitro-1-arylethane-1-ols were synthesized according to the procedure of Borah.27 Benzaldehyde (14.9 g, 140 mmol; 13.3 mL), nitromethane (25.6 g, 420 mmol, 22.8 mL), and imidazole (2.24 g, 32.9 mmol) were added to a round-bottom flask, then distilled water (280 mL) was added. After that, the mixture was stirred at 25 °C for 48 h. Diethyl ether (200 mL) was added to the reaction mixture, the aqueous phase was extracted with diethyl ether (2 × 100 mL). The combined organics were washed with brine (1 × 300 mL), dried over anhydrous sodium sulfate, filtered, and evaporated. The crude residue was used in the next step (oxidation to ketones) without purification. 2-Nitro-1-phenylethan-1-ol (1a′).28 Prepared according to the general procedure from benzaldehyde. The crude residue was used in the next step without purification. 2-Nitro-1-(4-nitrophenyl)ethan-1-ol (1b′).27 Prepared according to the general procedure from 4-nitrobenzaldehyde (21.2 g, 140 mmol, 13.7 mL). The crude residue was used in the next step without purification. 2-Nitro-1-(4-chlorophenyl)ethan-1-ol (1c′).29 Prepared according to the general procedure from 4-chlorobenzaldehyde (19.7 g, 140 mmol). The crude residue was used in the next step without purification. 2-Nitro-1-(3-nitrophenyl)ethan-1-ol (1d′).28 Prepared according to the general procedure from 3-nitrobenzaldehyde (21.2 g, 140 mmol). The crude residue was used in the next step without purification. 2-Nitro-1-(p-tolyl)ethan-1-ol (1e′).28 Prepared according to the general procedure from 3-nitrobenzaldehyde (21.2 g, 140 mmol). The crude residue was used in the next step without purification. General Procedure 2 for the Synthesis of 2-Nitro-1arylethanones. The desired ketones were synthesized from the appropriate alcohols by oxidation in the presence of Jones reagent (CrO3: 9.17 g, 91.7 mmol, and 8 mL conc. H2SO4 completed to 42 mL with distilled water) according to the modified procedure of Zhao.20 2-Nitro-1-phenylethan-1-ol (13.6 g, 81.4 mmol) was dissolved in acetone (130 mL), the mixture was cooled to 0 °C, and then Jones reagent was added dropwise in 30 min. After that the resulted mixture was stirred at 0−5 °C for the appropriate time. Diisopropyl alcohol (100 mL) and distilled water were added to the reaction mixture (100 mL), the aqueous phase was extracted with diethyl ether (3 × 100 mL). The combined organics were washed with brine (1 × 50 mL), dried over anhydrous sodium sulfate, filtered, and evaporated. Method A. The resulted crystalline solid was washed with diisopropyl ether affording the pure product as a white or a pale yellow solid. Method B. The crude residue was purified by column chromatography. 2-Nitro-1-phenylethan-1-one (1a″).30 Prepared according to the general procedure A from 2-nitro-1-phenylethan-1-ol. White crystalline solid (4.83 g, 29.3 mmol, 36%). Mp 104−105 °C; Rf = 0.36 (cyclohexane−ethyl acetate, 5:2). 1H NMR (400 MHz, DMSO-d6) δ 7.96−7.94 (m, 2H), 7.77−7.73 (m, 1H), 7.62−7.58 (m, 2H), 6.55 (s, 11757


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19.8, 19.3. IR νmax/cm−1 (solid): 2920, 2850, 1596, 1529, 1345, 1273, 1227, 1201, 1162, 1011, 809, 774, 703, 695. (Z)-4-Chloro-N-(2-nitro-1-(4-nitrophenyl)vinyl)aniline (1i). Prepared according to the general procedure A from 2-nitro-1-(4nitrophenyl)ethan-1-one (1.01 g, 4.80 mmol) and 4-chloroaniline (1.22 g, 9.60 mmol). The product was obtained as a yellow crystalline solid (1.13 g, 3.55 mmol, 74%). Mp 184−185 °C; Rf = 0.54 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 11.20 (s, 1H), 8.22 (d, J = 8.8 Hz, 2H), 7.51 (d, J = 8.8 Hz, 2H), 7.18 (d, J = 8.7 Hz, 2H), 6.76 (d, J = 10.3 Hz, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 152.5, 149.3, 137.9, 135.8, 132.49, 130.0, 129.9, 125.5, 124.5, 115.4. IR νmax/cm−1 (solid): 2924, 2856, 1572, 1521, 1485, 1347, 1283, 1273, 1194, 1091, 1013, 854, 704. HRMS m/z [M+H]+ Calculated for C14H11N3O4Cl: 320.0438; found 320.0426. (Z)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-3,4-dimethylaniline (1j). Prepared according to the general procedure B from 2-nitro-1-(4chlorophenyl)ethan-1-one (955 mg, 4.80 mmol) and 3,4-dimethyaniline (1.16 g, 9.60 mmol). The product was obtained as a light brown crystalline solid (130 mg, 0.432 mmol, 9%). Mp 141−142 °C; Rf = 0.50 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 11.39 (s, 1H), 7.31 (d, J = 8.7 Hz, 2H), 7.28−7.19 (m, 2H), 6.90 (d, J = 8.1 Hz, 1H), 6.70 (s, 1H), 6.68 (d, J = 2.5 Hz, 1H), 6.46 (dd, J = 8.1, 2.4 Hz, 1H), 2.15 (d, J = 8.6 Hz, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 154.8, 138.0, 137.2, 135.13, 135.06, 130.5, 130.4, 130.2, 129.4, 125.3, 121.7, 114.0, 19.9, 19.4. IR νmax/cm−1 (solid): 2920, 2851, 1590, 1559, 1483, 1445, 1353, 1270, 1226, 1198, 1160, 1089, 1013, 836, 769, 701. HRMS m/z [M+Na] + Calculated for C16H15N2O2ClNa: 325.0720; found 325.0715. (Z)-4-Chloro-N-(1-(4-chlorophenyl)-2-nitrovinyl)aniline (1k). Prepared according to the general procedure A from 2-nitro-1-(4chlorophenyl)ethan-1-one (955 mg, 4.80 mmol) and 4-chloroaniline (1.22 g, 9.60 mmol). The product was obtained as a light brown crystalline solid after recrystallization from ethanol (739 mg, 2.40 mmol, 50%). Mp 165−166 °C; Rf = 0.67 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 11.30 (s, 1H), 7.35 (d, J = 8.5 Hz, 2H), 7.27−7.21 (m, 2H), 7.17 (d, J = 8.7 Hz, 2H), 6.77 (s, 1H), 6.73 (d, J = 2.1 Hz, 2H); 13C{1H} NMR (75 MHz, CDCl3) δ 154.0, 137.7, 136.3, 132.0, 130.6, 130.1, 129.74, 129.65, 114.9. IR νmax/cm−1 (solid): 2918, 2850, 1600, 158, 1580, 1559, 1481, 1357, 1272, 1190, 1086, 1013, 914, 831, 769, 736, 700. HRMS m/z [M+H]+ Calculated for C14H11N2O2Cl2: 309.0198; found 309.0195. (Z)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-4-nitroaniline (1l). Prepared according to the general procedure B from 2-nitro-1-(4chlorophenyl)ethan-1-one (955 mg, 4.80 mmol) and 4-nitroaniline (1.33 g, 9.60 mmol). The product was obtained as a yellow crystalline solid (107 mg, 0.336 mmol, 7%). Mp 172−173 °C; Rf = 0.55 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 11.24 (s, 1H), 8.07 (d, J = 9.0 Hz, 2H), 7.41 (d, J = 8.5 Hz, 2H), 7.29 (d, J = 8.5 Hz, 2H), 6.88 (d, J = 9.0 Hz, 2H), 6.78 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 152.1, 144.7, 143.7, 138.4, 130.2, 129.9, 129.4, 125.2, 123.0, 117.1. IR νmax/cm−1 (solid): 2923, 2852, 1580, 1490, 1336, 1290, 1196, 1176, 1088, 836, 750,732. HRMS m/z [M +H]+ Calculated for C14H11N3O4Cl: 320.0438; found 320.0435. (Z)-N-(2-Nitro-1-(p-tolyl)vinyl)aniline (1m).33 Prepared according to the general procedure B from 2-nitro-1-(p-tolyl)ethan-1-one (859 mg, 4.80 mmol) and aniline. The product was obtained as a yellow crystalline solid (719 mg, 2.83 mmol, 59%). Mp 157−158 °C; Rf = 0.40 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 11.53 (s, 1H), 7.23−7.06 (m, 7H), 6.83 (d, J = 7.8 Hz, 2H), 6.77 (s, 1H), 2.35 (s, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 156.0, 141.6, 138.0, 129.9, 129.3, 128.8, 128.7, 126.0, 124.1, 114.3, 21.6. IR νmax/ cm−1 (solid): 2913, 1594, 1583, 1562, 1482, 1454, 1363, 1278, 1194, 825, 766, 754, 694. (Z)-3,4-Dimethyl-N-(2-nitro-1-(p-tolyl)vinyl)aniline (1n). Prepared according to the general procedure A from 2-nitro-1-(p-tolyl)ethan-1one (859 mg, 4.80 mmol) and 3,4-dimethyaniline (1.16 g, 9.60 mmol). The product was obtained as an orange crystalline solid after recrystallization form ethanol (352 mg, 1.25 mmol, 26%). Mp 149− 150 °C; Rf = 0.69 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 11.56 (s, 1H), 7.18 (q, J = 8.1 Hz, 4H), 6.90 (d, J =

(Z)-N-(2-Nitro-1-(4-chlorophenyl)vinyl)aniline (1c).34 Prepared according to the general procedure B from 2-nitro-1-(4-chlorophenyl)ethan-1-one (955 mg, 4.80 mmol) and aniline. The product was obtained as a yellow crystalline solid (539 mg, 1.97 mmol, 41%). Mp 160−161 °C; Rf = 0.55 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 11.43 (s, 1H), 7.34 (d, J = 8.6 Hz, 2H), 7.24 (dd, J = 14.0, 8.2 Hz, 4H), 7.14 (t, J = 7.3 Hz, 1H), 6.84 (d, J = 7.6 Hz, 2H), 6.75 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 154.4, 137.4, 137.2, 130.1, 123.0, 129.4, 129.3, 126.2, 124.1, 114.3. IR νmax/cm−1 (solid): 2922, 2853, 1582, 1560, 1483, 1361, 1280, 1191, 191, 1013, 919, 834, 755, 729, 694. (Z)-3,4-Dimethyl-N-(2-nitro-1-phenylvinyl)aniline (1d).32 Prepared according to the general procedure A from 2-nitro-1phenylethan-1-one and 3,4-dimethylaniline (1.16 g, 9.60 mmol). The product was obtained as a yellow crystalline solid (952 mg, 3.55 mmol, 74%). Mp 166−167 °C; Rf = 0.45 (cyclohexane−ethyl acetate, 5:2). 1 H NMR (300 MHz, CDCl3) δ 11.28 (s, 1H), 8.17 (d, J = 8.7 Hz, 2H), 7.56−7.42 (m, 2H), 6.89 (d, J = 8.0 Hz, 1H), 6.76−6.65 (m, 2H), 6.44 (dd, J = 8.3, 2.4 Hz, 1H), 2.14 (d, J = 8.2 Hz, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 153.4, 149.1, 138.5, 138.3, 135.6, 134.7, 130.6, 130.0, 125.5, 124.2, 121.9, 114.3, 19.9, 19.4. IR νmax/cm−1 (solid): 2920, 1596, 1569, 1599, 1571, 1485, 1358, 1276, 1232, 1205, 1165, 1111, 785, 767, 708. (Z)-N-(2-Nitro-1-phenylvinyl)cyclohexanamine (1e).35 Prepared according to the general procedure B from 2-nitro-1-phenylethan-1one and cyclohexaneamine (950 mg, 9.60 mmol). The product was obtained as a white crystalline solid (197 mg, 0.800 mmol, 17%). Mp 114−115 °C; Rf = 0.32 (cyclohexane−ethyl acetate, 7:3). 1H NMR (300 MHz, CDCl3) δ 7.76 (d, J = 7.2 Hz, 2H), 7.54−7.37 (m, 3H), 6.06 (s, 1H), 4.08−3.91 (m, 1H), 2.04 (d, J = 9.7 Hz, 2H), 1.89−1.59 (m, 3H), 1.53−1.35 (m, 2H), 1.33−1.14 (m, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 166.7, 135.1, 131.2, 128.5, 126.9, 48.7, 33.3, 25.6, 25.0. IR νmax/cm−1 (solid): 2929, 2853, 1625, 1535, 1328, 1150, 1084, 691, 676. (Z)-3,4-Dichloro-N-(2-nitro-1-phenylvinyl)aniline (1f). Prepared according to the general procedure A from 2-nitro-1-phenylethan-1one and 3,4-dichloroaniline (1.56 g, 9.60 mmol). The product was obtained as a yellow crystalline solid (665 mg, 2.16 mmol, 45%). Mp 139−140 °C; Rf = 0.28 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 11.29 (s, 1H), 7.53−7.44 (m, 1H), 7.40 (t, J = 7.4 Hz, 2H), 7.30 (d, J = 7.4 Hz, 2H), 7.21 (d, J = 8.6 Hz, 1H), 6.95 (d, J = 2.0 Hz, 1H), 6.77 (s, 1H), 6.59 (dd, J = 8.5, 2.1 Hz, 1H); 13 C{1H} NMR (75 MHz, CDCl3) δ 154.7, 137.5, 133.3, 131.5, 131.1, 130.8, 130.6, 129.8, 129.5, 128.7, 125.5, 123.1, 115.5. IR νmax/cm−1 (solid): 2918, 1596, 1588, 1560, 1456, 1354, 1247, 1195, 1108, 936, 878, 816, 763, 701, 659. HRMS m/z [M+H]+ Calculated for C14H11N2O2Cl2: 309.0198; found 309.0199. (Z)-4-Nitro-N-(2-nitro-1-phenylvinyl)aniline (1g). Prepared according to the general procedure B from 2-nitro-1-phenylethan-1-one and 4-nitroaniline (1.33 g, 9.60 mmol). The product was obtained as a yellow crystalline solid (172 mg, 0.604 mmol, 13%). Mp 125−126 °C; Rf = 0.51 (cyclohexane−ethyl acetate, 3:1). 1H NMR (300 MHz, CDCl3) δ 11.33 (s, 1H), 8.04 (d, J = 9.1 Hz, 2H), 7.56−7.49 (m, 1H), 7.42 (t, J = 7.6 Hz, 2H), 7.37−7.31 (m, 2H), 6.86 (d, J = 9.0 Hz, 2H), 6.80 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 153.4, 144.6, 144.0, 131.8, 131.1, 129.8, 128.6, 125.1, 122.9, 117.0. IR νmax/cm−1 (solid): 2923, 2852, 1584, 1568, 1490, 1337, 1291, 1195, 1178, 1109, 850, 768, 750, 704. HRMS m/z [M+H]+ Calculated for C14H12N3O4: 286.0828; found 286.0825. (Z)-3,4-Dimethyl-N-(2-nitro-1-(3-nitrophenyl)vinyl)aniline (1h).32 Prepared according to the general procedure A from 2-nitro-1-(3nitrophenyl)ethan-1-one (1.01 g, 4.80 mmol) and 3,4-dimethyaniline (1.16 g; 9.60 mmol). The product was obtained as a yellow crystalline solid (826 mg, 2.64 mmol, 55%). Mp 167−168 °C; Rf = 0.48 (cyclohexane−ethyl acetate, 7:3). 1H NMR (300 MHz, CDCl3) δ 11.32 (s, 1H), 8.28 (dd, J = 8.1, 2.2 Hz, 1H), 8.22 (s, 1H), 7.64 (d, J = 7.7 Hz, 1H), 7.55 (t, J = 7.9 Hz, 1H), 6.92 (d, J = 8.0 Hz, 1H), 6.74 (d, J = 10.4 Hz, 2H), 6.48 (dd, J = 8.0, 2.4 Hz, 1H), 2.16 (d, J = 7.0 Hz, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 153.0, 148.2, 138.2, 135.5, 134.5, 134.4, 133.8, 130.4, 130.1, 125.5, 125.3, 123.7, 121.9, 114.1, 11758


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(s, 3H); 13C{1H} NMR (62.5 MHz, DMSO-d6) δ 143.1, 141.5, 137.4, 137.2, 129.7, 119.4, 119.0, 26.2, 20.5; IR νmax/cm−1 (solid): 1575, 1483, 1224, 1168, 1024, 849, 632, 508; HRMS m/z [M−OTf]+ Calculated for C15H15FI: 341.0203; found: 341.0195. (4-(Ethoxycarbonyl)phenyl)(mesityl)iodonium Trifluoromethanesulfonate (2e).35 Prepared according to the general procedure from ethyl 4-iodobenzoate with the exception that 3-chloroperoxybenzoicacid, mesitylene, and the aryl iodide were stirred together at room temperature for 4 h before the addition of the trifluoromethanesulfonic acid. The product was obtained as a white solid (1.159 g, 47%). Mp 174−175 °C; 1H NMR (250 MHz, DMSO-d6): δ 8.09 (d, J = 8.4 Hz, 2H), 7.99 (d, J = 8.4 Hz, 2H), 7.24 (s, 2H), 4.31 (q, J = 6.9 Hz, 2H), 2.59 (s, 2H), 2.30 (s, 1H), 1.29 (t, J = 7.0 Hz, 3H); 13C{1H} NMR (62.5 MHz, DMSO-d6): δ 164.5, 143.4, 141.7, 134.7, 132.7, 131.9, 129.9, 122.6, 119.3, 61.4, 26.3, 20.5, 14.0; IR νmax/cm−1 (solid): 1723, 1584, 1458, 1395, 1272, 1238, 1161, 1103, 1025, 849, 753, 634, 516; HRMS m/z [M−OTf]+ Calculated for C18H20IO2: 395.0502; found: 395.0504. (2-Isopropylphenyl)(mesityl)iodonium Trifluoromethanesulfonate (2f).35 Prepared according to the general procedure from 1iodo-2-isopropylbenzene (3.0 mmol). The product was obtained as a white solid (2.049 g, 2.40 mmol, 80%). Mp 161−163 °C; 1H NMR (250 MHz, DMSO-d6) δ 8.09 (d, J = 8.0 Hz, 1H), 7.71−7.50 (m, 2H), 7.31 (ddd, J = 8.5, 6.4, 2.4 Hz, 1H), 7.21 (s, 2H), 3.37 (q, J = 7.0 Hz, 0.06H), 3.03 (p, J = 6.6 Hz, 1H), 2.60 (s, 6H), 2.28 (s, 3H), 1.13 (d, J = 6.7 Hz, 6H). 19F NMR (235 MHz, DMSO-d6) δ −77.72. 13 C{1H} NMR (63 MHz, DMSO) δ 150.2, 143.1, 141.8, 137.5, 133.0, 130.1, 129.7, 128.6, 123.4, 121.7, 118.5, 40.5, 40.2, 39.9, 39.5, 39.2, 38.9, 38.5, 37.3, 26.1, 23.6, 20.4. HRMS m/z [M]+ Calculated for C18H22I+: 365.0761; found 365.0758. (3-Bromophenyl)(mesityl)iodonium Trifluoromethanesulfonate (2g).35 Prepared according to the general procedure from 1-bromo3-iodobenzene. The product was obtained as a white solid (1.639 g, 2.97 mmol, 99%). Mp 172−174 °C; 1H NMR (250 MHz, DMSO-d6) δ 8.28 (s, 1H), 7.94−7.78 (m, 2H), 7.44 (t, J = 8.0 Hz, 1H), 7.23 (s, 2H), 2.60 (s, 6H), 2.30 (s, 3H). 19F NMR (235 MHz, DMSO-d6) δ −77.74. 19F NMR (235 MHz, DMSO-d6) δ −77.74. 13C{1H} NMR (63 MHz, DMSO) δ 143.4, 141.7, 136.1, 134.8, 133.5, 133.1, 129.9, 123.4, 122.6, 114.9, 40.5, 40.2, 39.9, 39.5, 39.2, 38.8, 38.5, 26.3, 20.5. Mesityl(3-pyridinium)iodonium Bistriflate (2h).37 To a solution of 3-iodopyridine (615 mg, 3,00 mmol) in CH2Cl2 (10 mL) was added TfOH (1.06 mL, 12 mmol, 4 equiv) and the resulting mixture was stirred at rt for 5 min. m-Chloroperbenzoic acid (m-CPBA 70% active oxidant, 1.11 g, 4.5 mmol, 1.5 equiv) followed by the mesitylene (550 μL, 3.9 mmol, 1.3 equiv) was then added. The reaction vessel was sealed and submitted to a 60 °C oil bath with stirring for 30 min. The reaction mixture was then allowed to reach rt after which it was concentrated in vacuo. Et2O (10 mL) was added and the mixture was stirred at 0 °C for 30 min. The resulting precipitate was filtered through a glass-sintered funnel and washed with additional Et2O (3 × 10 mL) to give the protonated N-heteroaryliodonium bistriflate. The product was obtained as a white solid (1.639 g, 2.64 mmol, 88%). Mp 139−141 °C (Lit.: 153−155 °C); 1H NMR (250 MHz, DMSO-d6) δ 9.07 (s, 1H), 8.79 (d, J = 4.8 Hz, 1H), 8.44 (d, J = 8.2 Hz, 1H), 7.56 (dd, J = 8.2, 4.7 Hz, 1H), 7.22 (s, 2H), 2.61 (s, 6H), 2.28 (s, 3H). 19F NMR (235 MHz, DMSO-d6) δ −77.77. 13C{1H} NMR (63 MHz, DMSO) δ 152.67, 151.70, 143.45, 142.48, 141.73, 129.96, 127.26, 123.33, 122.66, 118.20, 114.15, 40.52, 40.19, 39.85, 39.52, 39.19, 38.85, 38.52, 26.41, 20.56. General Procedure 4 for the One-Pot Synthesis of (Z)-N-(2Nitro-1-arlylvinyl)-N-arylanilines. (Z)-N-(2-Nitro-1-phenylvinyl)aniline (1a) (120 mg, 0.500 mmol), diaryl iodonium salt (0.750 mmol, 1.5 equiv), N,N-diisopropylethylamine (129 mg, 1.00 mmol, 172 μL, 2.0 equiv), and copper(I)chloride (1.24 mg; 0.013 mmol, 2.5 mol%) were added to a 4 mL vial; then, the system was charged with nitrogen. Dimethylformamide (2 mL) was added under an argon atmosphere; then, the reaction mixture was stirred at 50 °C for the appropriate time. Saturated sodium hydrogen carbonate solution (10 mL) was added to the mixture, the aqueous layer was extracted with dichloromethane (4 × 10 mL), and the combined organics were

8.1 Hz, 1H), 6.77 (s, 1H), 6.71 (s, 1H), 6.48 (dd, J = 8.2, 2.4 Hz, 1H), 2.37 (s, 3H), 2.16 (d, J = 9.5 Hz, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 156.2, 141.3, 137.6, 135.3, 134.5, 130.0, 129.6, 128.8, 128.5, 124.9, 121.3, 113.6, 21.5, 19.8, 19.3. IR νmax/cm−1 (solid): 2918, 1589, 1562, 1483, 1445, 1354, 1270, 1226, 1197, 1160, 1104, 1011, 823, 770, 700. HRMS m/z [M+Na]+ Calculated for C17H18N2O2Na: 305.1266; found 305.1260. (Z)-4-Chloro-N-(2-nitro-1-(p-tolyl)vinyl)aniline (1o). Prepared according to the general procedure A from 2-nitro-1-(p-tolyl)ethan-1one (859 mg, 4.80 mmol) and 4-chloroaniline (1.22 g, 9.60 mmol). The product was obtained as a yellow crystalline solid after recrystallization form ethanol (581 mg, 2.02 mmol, 42%). Mp 125− 126 °C; Rf = 0.67 (cyclohexane−ethyl acetate, 5:2). 1H NMR (300 MHz, CDCl3) δ 11.42 (s, 1H), 7.17 (d, J = 9.3 Hz, 6H), 6.84−6.72 (m, 3H), 2.38 (s, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 155.5, 141.7, 136.4, 131.4, 129.9, 129.3, 128.5, 128.2, 125.0, 114.5, 21.5. IR νmax/cm−1 (solid): 2919, 1600, 1590, 1560, 1483, 1359, 1289, 1273, 1193, 1182, 1092, 1012, 915, 825, 767, 699. HRMS m/z [M+Na]+ Calculated for C15H13N2O2ClNa: 311.0563; found 311.0563. General Procedure 3 for the One-Pot Synthesis of Arylmesityliodonium Triflates. Arylmesityliodonium triflates (2a−2i) were synthesized in a one-pot procedure from the appropriate iodoarene and mesitylene according to the modified procedure8b of Olofsson.36 m-Chloroperbenzoic acid (65% active oxidant, 1.32 g, 5.00 mmol) and the appropriate iodoarene (4.50 mmol) were dissolved in dichloromethane (20 mL). Mesitylene (696 μL, 5.00 mmol) was added, and the solution was cooled to 0 °C. Trifluoromethanesulfonic acid (825 mg, 486 μL, 5.50 mmol) was added dropwise in 5 min, and the resulting reaction mixture was allowed to warm to room temperature over 2 h. The volatile components were removed under reduced pressure, and the resulting material was suspended in diethyl ether (40 mL). The suspension was stored at −20 °C for 2 h. The resulting crystals were filtered off and were washed with ether to give the appropriate arylmesityliodonium triflate as a solid, which was dried at 100 °C under vacuum. Mesityl(phenyl)iodonium Trifluoromethanesulfonate (2a).35 Prepared according to the general procedure from iodobenzene. The product was obtained as a white solid (1.71 g, 3.62 mmol, 80%). Mp 147−148 °C; 1H NMR (250 MHz, DMSO-d6) δ 7.99 (d, J = 7.7 Hz, 2H), 7.64 (t, J = 7.3 Hz, 1H), 7.50 (t, J = 7.4 Hz, 2H), 7.22 (s, 2H), 2.60 (s, 6H), 2.29 (s, 3H); 13C{1H} NMR (62.5 MHz, DMSO-d6) δ 143.1, 141.5, 134.5, 131.8, 131.7, 129.7, 122.5, 114.5, 26.2, 20.5; IR νmax/ cm−1 (solid): 1443, 1246, 1157, 1025, 856, 742, 632, 572, 515, 454; HRMS m/z [M−OTf]+ Calculated for C15H16I: 323.0291; found 323.0289. 4-Methylphenyl(mesityl)iodonium Trifluoromethanesulfonate (2b).35 Prepared according to the general procedure from 4iodotoluene. The product was obtained as a white solid (2.07 g, 4.26 mmol, 95%). Mp 183−184 °C; 1H NMR (250 MHz, DMSO-d6) δ 7.88 (d, J = 8.4 Hz, 2H), 7.30 (d, J = 8.2 Hz, 2H), 7.20 (s, 2H), 2.60 (s, 6H), 2.32 (s, 3H), 2.28 (s, 3H); 13C{1H} NMR (62.5 MHz, DMSO-d6) δ 142.9, 142.2, 141.4, 134.5, 132.4, 129.7, 122.7, 110.8, 26.2, 20.7, 20.4; IR νmax/cm−1 (solid): 1452, 1246, 1157, 1024, 804, 632, 481; HRMS m/z [M−OTf]+ Calculated for C16H18I: 337.0448; found 337.0444. 4-Bromophenyl(mesityl)iodonium Trifluoromethanesulfonate (2c).35 Prepared according to the general procedure from 4bromoiodobenzene. The product was obtained as a white solid (1.69 g, 3.07 mmol, 68%). Mp 179−180 °C; 1H NMR (250 MHz, DMSO-d6) δ 7.90 (d, J = 8.5 Hz, 2H), 7.70 (d, J = 8.5 Hz, 2H), 7.22 (s, 2H), 2.60 (s, 6H), 2.29 (s, 3H); 13C{1H} NMR (62.5 MHz, DMSO-d6) δ 143.2, 141.5, 136.3, 134.6, 129.8, 125.7, 122.7, 113.0, 26.2, 20.5; IR νmax/cm−1 (solid): 1473, 1245, 1232, 1024, 807, 631, 518, 475; HRMS m/z [M−OTf]+ Calculated for C15H15BrI: 400.9396; found: 400.9399. 4-Fluorophenyl(mesityl)iodonium Trifluoromethanesulfonate (2d).35 Prepared according to the general procedure from 4fluoroiodobenzene. The product was obtained as an off-white solid (1.63 g, 3.33 mmol, 74%). Mp 178−179 °C; 1H NMR (250 MHz, DMSO-d6) δ 7.37 (t, J = 8.7 Hz, 2H), 7.22 (s, 2H), 2.60 (s, 6H), 2.29 11759


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The Journal of Organic Chemistry washed with saturated litium chloride solution (4 × 30 mL), with brine (1 × 30 mL), dried over anhydrous sodium sulfate, filtered, and evaporated. The crude residue was purified by column chromatography. (E)-N-(2-Nitro-1-phenylvinyl)-N-phenylaniline and (Z)-N-(2-Nitro1-phenylvinyl)-N-phenylaniline (3aa). Prepared according to the general procedure from (Z)-N-(2-nitro-1-phenylvinyl)aniline and phenyl(mesityl)iodonium trifluoromethanesulfonate (354 mg, 0.750 mmol) for 3 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (105 mg, 0.332 mmol, 66%). Mp 147−148 °C; Rf = 0.30 (cyclohexane−ethyl acetate, 8:1). 1H NMR (300 MHz, CDCl3) δ 7.55 (d, J = 7.4 Hz, 1H), 7.42−7.32 (m, 2H), 7.32−7.21 (m, 6H), 7.19−7.04 (m, 6H), 6.93 (s, 0.5H), 6.81 (s, 0.5H); 13C{1H} NMR (75 MHz, CDCl3) δ 159.6, 152.9, 146.2, 144.9, 135.6, 132.7, 131.2, 130.3, 130.13, 130.05, 129.8, 129.4, 129.0, 128.5, 127.5, 126.9, 125.6, 125.3, 125.1, 124.1. IR νmax/cm−1 (solid): 1558, 1491, 1342, 1266, 1254, 57, 695. HRMS m/z [M+H]+ Calculated for C20H17N2O2: 317.1290; found 317.1287. (E)-4-Methyl-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)4-Methyl-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3ab). Prepared according to the general procedure from (Z)-N-(2-nitro-1phenylvinyl)aniline and 4-methylphenyl(mesityl)iodonium trifluoromethanesulfonate (365 mg, 0.750 mmol) for 5 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (129 mg, 0.391 mmol, 78%). Mp 142−143 °C; Rf = 0.38 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 7.54 (d, J = 6.4 Hz, 1H), 7.44−7.20 (m, 6H), 7.18−6.95 (m, 7H), 6.90 (s, 0.3H), 6.80 (s, 0.7H), 2.29 (s, 3H); 13 C{1H} NMR (75 MHz, CDCl3) δ 159.8, 153.1, 146.4, 145.0, 143.7, 142.4, 137.0, 135.8, 135.5, 132.8, 131.1, 130.5, 130.4, 130.1, 130.0, 129.7, 129.4, 129.0, 128.4, 127.5, 127.3, 126.7, 125.4, 125.1, 124.9, 124.8, 123.7, 21.2, 21.1. IR νmax/cm−1 (solid): 1554, 1493, 1452, 1342, 1254, 778, 717, 696. HRMS m/z [M+H]+ Calculated for C21H19N2O2: 331.1447; found 331.1439. (E)-4-Bromo-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)4-Bromo-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3ac). Prepared according to the general procedure from (Z)-N-(2-nitro-1phenylvinyl)aniline and 4-bromophenyl(mesityl)iodonium trifluoromethanesulfonate (413 mg, 0.750 mmol) for 12 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (114 mg, 0.290 mmol, 58%). Mp 139−140 °C; Rf = 0.40 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.52 (d, J = 7.2 Hz, 1H), 7.44−7.16 (m, 8.5H), 7.08 (t, J = 9.7 Hz, 2.5H), 6.96 (d, J = 10.9 Hz, 2H), 6.91 (s, 0.5H), 6.79 (s, 0.5H); 13C{1H} NMR (75 MHz, CDCl3) δ 158.9, 152.5, 145.6, 145.3, 144.8, 144.0, 135.1, 132.9, 132.6, 131.4, 130.3, 130.2, 130.10, 130.05, 129.6, 129.2, 128.9, 128.6, 127.4, 127.19, 126.24, 125.9, 125.1, 125.0, 120.1, 118.6. IR νmax/cm−1 (solid): 1560, 1486, 1373, 1300, 1254, 1073, 1011, 771, 761, 732, 694. HRMS m/z [M +H]+ Calculated for C20H16N2O2Br: 395.0395; found 395.0386. (E)-4-Fluoro-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)-4Fluoro-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3ad). Prepared according to the general procedure from (Z)-N-(2-nitro-1phenylvinyl)aniline and 4-fluorophenyl(mesityl)iodonium trifluoromethanesulfonate (368 mg, 0.750 mmol) for 5 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (120 mg, 0.359 mmol, 72%). Mp 110− 111 °C; Rf = 0.28 (cyclohexane−ethyl acetate, 9:1). 1H NMR (300 MHz, CDCl3) δ 7.54 (d, J = 7.3 Hz, 1H), 7.45−7.18 (m, 7H), 7.15− 7.02 (m, 4H), 6.97 (dd, J = 8.0, 2.9 Hz, 2H), 6.93 (s, 0.4H), 6.79 (s, 0.6H); 13C{1H} NMR (75 MHz, CDCl3) δ 161.7, 159.4, 159.1, 152.8, 146.0, 144.6, 142.1, 142.0, 140.6, 135.1, 132.3, 131.17, 130.15, 130.0, 129.9, 129.8, 129.3, 129.1, 129.0, 129.0, 128.4, 127.2, 126.9, 126.6, 126.52, 125.47, 124.9, 124.6, 123.8, 116.8, 116.5, 116.4, 116.1. IR νmax/ cm−1 (solid): 2920, 1560, 1503, 1492, 142, 1256, 1219, 1153, 771, 720, 693. HRMS m/z [M+H]+ Calculated for C20H16N2O2F: 335.1184; found 335.1184. (E)-2-Isopropyl-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)- 2-Isopropyl-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3af).

Prepared according to the general procedure from (Z)-N-(2-nitro-1phenylvinyl)aniline and (2-isopropylphenyl)(mesityl)iodonium trifluoromethanesulfonate for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (120 mg, 0.078 mmol, 16%). Mp 155−158 °C; Rf = 0.4 (cyclohexane−ethyl acetate, 8:1). 1H NMR (250 MHz, Chloroform-d) δ 7.43 (dd, J = 6.5, 1.7 Hz, 1H), 7.38−6.83 (m, 22H), 7.00−6.83 (m, 6H), 6.71 (s, 0.4H), 6.61 (s, 1.6H), 3.25 (hept, J = 6.8 Hz, 1.6H), 3.09 (dt, J = 13.4, 6.6 Hz, 0.4H), 1.19 (d, J = 6.8 Hz, 6H), 1.10 (d, J = 6.8 Hz, 1H), 0.83 (d, J = 6.8 Hz, 5H). 13C{1H} NMR (63 MHz, CDCl3) δ 159.88, 145.45, 144.50, 141.53, 132.57, 130.50, 130.03, 129.85, 129.18, 128.99, 128.94, 128.62, 128.40, 128.11, 128.00, 127.42, 126.88, 125.88, 123.10, 77.67, 77.16, 76.65, 28.17, 23.98, 23.40. IR νmax/cm−1 (solid): 1585, 1558, 1491, 1467, 1454, 1447, 1385, 1365, 1340, 1310, 1283, 1262, 761, 748, 695. HRMS m/z [M +H]+ Calculated for C23H23N2O2: 359.1754; found 359.1751. (E)-N-(2-Nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline and (Z)-N(2-Nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline (3ba). Prepared according to the general procedure from (Z)-N-(2-nitro-1-(4nitrophenyl)vinyl)aniline (143 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 5 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (143 mg, 0.396 mmol, 79%). Mp 195−196 °C; Rf = 0.24 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 8.35−8.00 (m, 2H), 7.77−7.51 (m, 2H), 7.43−7.24 (m, 4H), 7.24−7.15 (m, 2H), 7.15−7.04 (m, 4H), 6.91 (s, 0.3H), 6.84 (s, 0.7H); 13C{1H} NMR (62.5 MHz, CDCl3) δ 157.1, 148.5, 145.6, 144.2, 139.9, 131.24, 131.17, 130.3, 129.9, 127.8, 127.6, 126.4, 125.1, 124.34, 124.31, 123.8. IR νmax/cm−1 (solid): 2920, 1555, 1521, 1491, 1338, 1251, 866, 587, 698. HRMS m/z [M+H]+ Calculated for C20H16N3O4: 362.1141; found 362.1128. (E)-4-Methyl-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline and (Z)-4-Methyl-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline (3bb). Prepared according to the general procedure from (Z)N-(2-nitro-1-(4-nitrophenyl)vinyl)aniline (143 mg, 0.500 mmol) and 4-methylphenyl(mesityl)iodonium trifluoromethanesulfonate (365 mg, 0.750 mmol) for 3 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (133 mg, 0.355 mmol, 71%). Mp 227−228 °C; Rf = 0.30 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 8.11 (d, J = 8.2 Hz, 2H), 7.53 (d, J = 8.2 Hz, 2H), 7.27 (d, J = 6.8 Hz, 2H), 7.18 (d, J = 6.5 Hz, 1H), 7.09 (d, J = 8.3 Hz, 4H), 6.99 (d, J = 8.3 Hz, 2H), 6.82 (s, H), 2.29 (s, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 157.0, 148.3, 144.2, 141.5, 139.8, 137.8, 131.1, 131.0, 130.8, 130.4, 130.1, 129.7, 127.495 127.4, 127.3, 125.0, 124.7, 124.1, 123.8, 123.6, 21.2. IR νmax/cm−1 (solid): 2918, 1636, 1522, 1451, 1344, 1264, 870, 854, 743, 718, 694. HRMS m/z [M+H]+ Calculated for C21H18N3O4: 376.1297; found 376.1285. (E)-4-Bromo-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline and (Z)-4-Bromo-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline (3bc). Prepared according to the general procedure from (Z)-N-(2nitro-1-(4-nitrophenyl)vinyl)aniline (143 mg, 0.500 mmol) and 4bromophenyl(mesityl)iodonium trifluoromethanesulfonate (413 mg, 0.750 mmol) for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (102 mg, 0.232 mmol, 47%). Mp 242−243 °C; Rf = 0.32 (cyclohexane−ethyl acetate, 5:1).1H NMR (300 MHz, DMSOd6) δ 8.16 (t, J = 7.9 Hz, 2H), 7.88 (dd, J = 30.5, 8.6 Hz, 2H), 7.52 (dd, J = 22.8, 8.6 Hz, 2H), 7.44−7.31 (m, 4H), 7.28 (d, J = 7.3 Hz, 1H), 7.11 (t, J = 7.4 Hz, 1H), 7.04 (d, J = 8.7 Hz, 1H), 6.58 (s, 1H); 13 C{1H} NMR (75 MHz, DMSO-d6) δ 158.1, 149.5, 149.2, 148.1, 145.1, 145.0, 143.8, 143.3, 141.6, 140.1, 133.2, 132.8, 132.1, 131.7, 130.41, 130.36, 130.1, 128.34, 128.28, 126.4, 126.3, 125.2, 124.2, 123.5, 121.8, 121.0. 117.89.IR νmax/cm−1 (solid): 2918, 2853, 1556, 1522, 1488, 1450, 1337, 1273, 1252, 1012, 872, 858, 717, 700. HRMS m/z [M+H]+ Calculated for C20H15N3O4Br: 440.0246; found 440.0250. (E)-4-Fluoro-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline and (Z)-4-Fluoro-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline (3bd). Prepared according to the general procedure from (Z)-N-(211760


Article

The Journal of Organic Chemistry nitro-1-(4-nitrophenyl)vinyl)aniline (143 mg, 0.500 mmol) and 4fluorophenyl(mesityl)iodonium trifluoromethanesulfonate (368 mg, 0.750 mmol) for 5 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (130 mg, 0.343 mmol, 69%). Mp 182−183 °C; Rf = 0.30 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 8.42−8.00 (m, 2H), 7.58 (dd, J = 35.2, 8.1 Hz, 2H), 7.45−7.17 (m, 4H), 7.10 (d, J = 6.5 Hz, 3H), 7.00 (t, J = 8.2 Hz, 2H), 6.81 (s, 1H); 13 C{1H} NMR (75 MHz, CDCl3) δ 163.0, 156.8, 148.4, 144.0, 139.5, 130.9, 130.2, 129.5, 129.3, 129.1, 128.5, 127.7, 127.3, 124.3, 124.2, 123.7, 120.6, 117.4, 117.1, 107.3. IR νmax/cm−1 (solid): 1560, 1523, 1506, 1343, 1257, 1223, 872, 858, 746, 721, 694. HRMS m/z [M+H]+ Calculated for C20H15N3O4F: 380.1047; found 380.1040. Ethyl (E)-4-((2-Nitro-1-(4-nitrophenyl)vinyl)(phenyl)amino)benzoate and Ethyl (Z)-4-((2-Nitro-1-(4-nitrophenyl)vinyl)(phenyl)amino)benzoate (3be). Prepared according to the general procedure from (Z)-N-(2-nitro-1-(4-nitrophenyl)vinyl)aniline (143 mg, 0.500 mmol) and 4-ethoxycarbonyl-phenyl(mesityl)iodonium trifluoromethanesulfonate (408 mg, 0. 750 mmol) for 3 h. Purification of the crude product by column chromatography on silica gel afforded the product as a red crystalline solid (105 mg, 0.271 mmol, 54%). Mp 82− 83 °C; Rf = 0.32 (cyclohexane−ethyl acetate, 4:1). 1H NMR (300 MHz, CDCl3) δ 8.39−8.03 (m, 2H), 8.01−7.86 (m, 2H), 7.72 (d, J = 7.6 Hz, 1H), 7.56 (d, J = 8.8 Hz, 1H), 7.44−7.23 (m, 3H), 7.21−7.05 (m, 4H), 7.00 (s, 0.46H), 6.87 (s, 0.54H), 4.34 (q, J = 7.0 Hz, 2H), 1.36 (t, J = 7.1 Hz, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 165.8, 165.5, 155.8, 149.4, 149.1, 148.6, 148.0, 144.4, 144.0, 141.6, 139.2, 132.0, 131.3, 131.1, 130.9, 130.5, 130.0, 128.0, 127.9, 127.4, 126.8, 126.7, 126.3, 125.5, 124.3, 123.8, 123.4, 120.7, 117.1, 115.3, 61.5, 61.3, 14.52, 14.47. IR νmax/cm−1 (solid): 1707, 1590, 1520, 1344, 1263, 1172, 1104, 856, 762, 696. HRMS m/z [M+H]+ Calculated for C23H20N3O6: 434.1354; found 434.1339. (E)-N-(1-(4-chlorophenyl)-2-nitrovinyl)-N-phenylaniline and (Z)N-(1-(4-chlorophenyl)-2-nitrovinyl)-N-phenylaniline (3ca). Prepared according to the general procedure from (Z)-N-(2-nitro-1-(4chlorophenyl)vinyl)aniline (137 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 4 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (123 mg, 0.351 mmol, 70%). Mp 161−162 °C; Rf = 0.36 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.47 (d, J = 8.5 Hz, 1H), 7.33−7.24 (m, 6H), 7.22 (s, 1H), 7.17 (t, J = 7.4 Hz, 1H), 7.12−7.03 (m, 5H), 6.88 (s, 0.44H), 6.78 (s, 0.56H); 13C{1H} NMR (75 MHz, CDCl3) δ 158.2, 151.6, 145.9, 144.7, 137.4, 136.2, 134.1, 131.5, 131.2, 130.6, 129.9, 129.5, 129.4, 128.9, 127.4, 127.1, 125.8, 126.0, 125.0, 124.4. IR νmax/ cm−1 (solid): 1590, 1575, 1488, 1339, 1250, 1089, 1013, 756, 694. HRMS m/z [M+H]+ Calculated for C20H16N2O2Cl: 351.0900; found 351.0890. (E)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-4-methyl-N-phenylaniline and (Z)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-4-methyl-N-phenylaniline (3cb). Prepared according to the general procedure from (Z)-N(2- nitro-1-(4-chlorophenyl)vinyl)aniline (137 mg, 0.500 mmol) and 4-methylphenyl(mesityl)iodonium trifluoromethanesulfonate (365 mg, 0.750 mmol) for 12 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (145 mg, 0.398 mmol, 80%). Mp 127−128 °C; Rf = 0.33 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.46 (d, J = 8.1 Hz, 1H), 7.34−7.20 (m, 5H), 7.16 (d, J = 7.1 Hz, 1H), 7.06 (t, J = 9.1 Hz, 4H), 6.97 (d, J = 6.9 Hz, 2H), 6.85 (s, 0.34H), 6.77 (s, 0.66H), 2.33−2.23 (m, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 158.4, 151.7, 146.2, 144.8, 143.4, 142.162 137.3, 137.2, 136.1, 135.8, 134.3, 131.5, 131.4, 131.3, 130.6, 130.2, 129.8, 129.5, 129.4, 128.8, 127.3, 127.2, 126.9, 125.6, 125.0, 124.8, 124.8, 123.9, 21.2, 21.1. IR νmax/cm−1 (solid): 1634, 1548, 1489, 1337, 1250, 1090, 1013, 859, 759, 717, 694. HRMS m/z [M+H]+ Calculated for C21H18N2O2Cl: 365.1057; found 365.1050. (E)-4-Bromo-N-(1-(4-chlorophenyl)-2-nitrovinyl)-N-phenylaniline and (Z)-4-Bromo-N-(1-(4-chlorophenyl)-2-nitrovinyl)-N-phenylaniline (3cc). Prepared according to the general procedure from (Z)-N(2- nitro-1-(4-chlorophenyl)vinyl)aniline (137 mg, 0.500 mmol) and

4-bromophenyl(mesityl)iodonium trifluoromethanesulfonate (413 mg, 0.750 mmol) for 22 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (118 mg, 0.276 mmol, 55%). Mp 171−172 °C; Rf = 0.33 (cyclohexane−ethyl acetate, 9:1). 1H NMR (300 MHz, CDCl3) δ 7.46 (d, J = 8.4 Hz, 1H), 7.33−7.24 (m, 5H), 7.20 (t, J = 6.5 Hz, 1H), 7.14−7.01 (m, 2H), 6.94 (d, J = 6.8 Hz, 2H), 6.90 (s, 0.34H), 6.77 (s, 0.66H); 13C{1H} NMR (75 MHz, CDCl3) δ 157.6, 151.2, 145.4, 145.1, 144.5, 143.8, 137.7, 136.5, 133.1, 132.7, 131.41, 131.35, 130.6, 130.2, 129.7, 129.6, 129.0, 128.8, 127.4, 127.3, 126.2, 126.1, 125.8, 125.2, 125.0, 120.4, 118.8. IR νmax/cm−1 (solid): 2918, 1551, 1487, 1340, 1256, 1088, 1069, 1012, 737, 698. HRMS m/z [M+H]+ Calculated for C20H15N2O2ClBr: 429.0005; found 429.0009. (E)-3,4-Dimethyl-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)-3,4-Dimethyl-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3da). Prepared according to the general procedure from (Z)-3,4-dimethylN-(2-nitro-1-phenylvinyl)aniline (134 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 5 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (150 mg, 0.437 mmol, 88%). Mp 101−102 °C; Rf = 0.37 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.54 (d, J = 7.2 Hz, 1H), 7.42−7.15 (m, 6H), 7.14−6.95 (m, 4H), 6.88 (dd, J = 14.7, 7.4 Hz, 2H), 6.81 (s, 1H), 6.77 (s, 1H), 2.33−2.05 (m, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 159.9, 146.5, 144.9, 143.9, 142.6, 138.5, 137.7, 135.9, 134.2, 132.9, 131.02, 130.95, 130.6, 130.5, 130.4, 130.1, 129.9, 129.5, 129.3, 128.9, 128.4, 127.5, 126.5, 126.2, 125.3, 125.0, 124.8, 124.7, 123.6, 122.7, 20.00, 19.96, 19.50, 19.45. IR νmax/cm−1 (solid): 2918, 1551, 1492, 1447, 1339, 1246, 1025, 1001, 735, 716, 694. HRMS m/z [M+H]+ Calculated for C22H21N2O2: 345.1603; found 345.1605. (E)-3,4-Dichloro-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)-3,4-Dichloro-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3fa). Prepared according to the general procedure from (Z)-3,4-dichloroN-(2-nitro-1-phenylvinyl)aniline (154 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 18 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (98.0 mg, 0.255 mmol, 51%). Mp 70−71 °C; Rf = 0.30 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.52 (d, J = 7.3 Hz, 1H), 7.42−7.22 (m, 7H), 7.17 (s, 1H), 7.14−7.05 (m, 3H), 7.01−6.86 (m, 1.5H), 6.78 (s, 0.5H); 13C{1H} NMR (300 MHz, CDCl3) δ 152.0, 145.7, 145.1, 134.7, 133.4, 132.0, 131.7, 131.2, 131.1, 131.0, 130.58, 130.56, 130.3, 130.10, 130.06, 129.7, 129.3, 128.93, 128.88, 128.7, 127.5, 127.3, 126.6, 126.4, 126.2, 125.9, 125.8, 125.2, 123.6. IR νmax/cm−1 (solid): 2922, 1586, 1560, 1492, 1469, 1310, 1254, 1132, 1028, 769, 695. HRMS m/z [M+H]+ Calculated for C20H15N2O2Cl2: 385.0511; found 385.0508. (E)-N-(3,4-Dichlorophenyl)-N-(2-nitro-1-phenylvinyl)pyridin-3amine or (Z)-N-(3,4-Dichlorophenyl)-N-(2-nitro-1-phenylvinyl)pyridin-3-amine (3fh). Prepared according to the general procedure from (Z)-3,4-dichloro-N-(2-nitro-1-phenylvinyl)aniline (154 mg, 0.500 mmol) and mesityl(pyridin-3-yl)iodonium trifluoromethanesulfonate for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange oil (62.5 mg, 0.162 mmol, 33%). Rf = 0.15 (cyclohexane−ethyl acetate, 7:3). 1H NMR (250 MHz, Chloroform-d) δ 8.36−8.24 (m, 4H), 7.52−7.43 (m, 3H), 7.55−7.07 (m, 12H), 7.20−7.09 (m, 4H), 6.98 (s, 1,3H), 6.94 (dd, J = 8.6, 2.6 Hz, 1H), 6.88 (dd, J = 8.7, 2.6 Hz, 1H), 6.73 (s, 0.4H). 13C{1H} NMR (63 MHz, CDCl3) δ 157.66, 151.31, 148.23, 147.61, 146.52, 145.90, 144.52, 143.58, 141.83, 134.13, 134.04, 133.65, 133.53, 132.04, 131.70, 131.62, 131.26, 130.79, 129.92, 129.50, 129.41, 128.83, 128.78, 127.41, 126.33, 126.26, 125.64, 124.10, 123.35, 77.67, 77.16, 76.65, 30.99. IR νmax/cm−1 (solid): 1585, 1571, 1558, 1467, 1363, 1342, 1309, 1296, 1268, 1258, 1223, 1132, 772, 708, 697. HRMS m/z [M+H]+ Calculated for C19H14Cl2N3O2: 386.0458; found 386.0458. (E)-4-Nitro-N-(2-nitro-1-phenylvinyl)-N-phenylaniline and (Z)-4Nitro-N-(2-nitro-1-phenylvinyl)-N-phenylaniline (3ga). Prepared according to the general procedure from (Z)-4-nitro-N-(2-nitro-1phenylvinyl)aniline (143 mg, 0.500 mmol) and phenyl(mesityl)11761


Article

The Journal of Organic Chemistry iodonium trifluoromethanesulfonate for 16 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (103 mg, 0.285 mmol, 57%). Mp 149− 150 °C; Rf = 0.28 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 8.10 (d, J = 9.1 Hz, 2H), 7.60−7.50 (m, 2H), 7.46− 7.23 (m, 6H), 7.16 (t, J = 8.4 Hz, 4H), 7.10 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 151.9, 151.4, 144.1, 143.7, 134.1, 132.0, 123.0, 129.9, 129.5, 128.3, 126.9, 125.9, 125.4, 122.8. IR νmax/cm−1 (solid): 1586, 1512, 1491, 1336, 1298, 1274, 1111, 975, 850, 751, 732, 695. HRMS m/z [M+H]+ Calculated for C20H16N3O4: 362.1141; found 362.1144. (E)-3,4-Dimethyl-N-(2-nitro-1-(3-nitrophenyl)vinyl)-N-phenylaniline and (Z)-3,4-Dimethyl-N-(2-nitro-1-(3-nitrophenyl)vinyl)-N-phenylaniline (3ha). Prepared according to the general procedure from (Z)-3,4-dimethyl-N-(2-nitro-1-(3-nitrophenyl)vinyl)aniline (157 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 3 h. Purification of the crude product by column chromatography on silica gel afforded the product as a drab crystalline solid (120 mg, 0.308 mmol, 62%). Mp 173−174 °C; Rf = 0.52 (cyclohexane−ethyl acetate, 7:3). 1H NMR (300 MHz, CDCl3) δ 8.19 (s, 1H), 8.13 (d, J = 8.3 Hz, 1H), 7.70 (d, J = 7.7 Hz, 1H), 7.46 (t, J = 8.0 Hz, 1H), 7.26 (t, J = 7.3 Hz, 2H), 7.15 (d, J = 7.1 Hz, 1H), 7.07 (t, J = 8.8 Hz, 3H), 6.92 (s, 1H), 6.88−6.81 (m, 2H), 2.18 (d, J = 5.3 Hz, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 156.9, 148.2, 144.1, 141.8, 138.9, 136.6, 135.9, 135.6, 135.0, 131.2, 130.8, 130.1, 130.0, 129.6, 129.3, 128.3, 127.5, 127.3, 126.2, 125.9, 125.5, 124.94, 124.88, 124.788, 124.7, 124.5, 123.7, 122.7, 20.0, 19.5. IR νmax/cm−1 (solid): 2920, 1528, 1452, 1338, 1254, 1003, 736, 718, 696. HRMS m/z [M+H]+ Calculated for C22H20N3O4: 390.1454; found 390.1451. ( E )- N - ( 3 - B r om op h e n y l) - 3 , 4 - di m e th y l - N - ( 2 - n i tr o - 1 - (3 nitrophenyl)vinyl)aniline and (Z)-N-(3-Bromophenyl)-3,4-dimethylN-(2-nitro-1-(3-nitrophenyl)vinyl)aniline (3hg). Prepared according to the general procedure from (Z)-3,4-dimethyl-N-(2-nitro-1-(3nitrophenyl)vinyl)aniline (157 mg, 0.500 mmol) and (3bromophenyl)(mesityl)iodonium trifluoromethanesulfonate for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as a orange crystalline solid (55 mg, 0.117 mmol, 24%). Mp 142−144 °C; Rf = 0.50 (cyclohexane−ethyl acetate, 7:3). 1H NMR (250 MHz, Chloroform-d) δ 24H: 8.39−8.34 (m), 8.27−8.08 (m), 7.97 (s), 7.86 (d, J = 7.7 Hz), 7.70 (d, J = 7.7 Hz), 7.50 (dt, J = 11.1, 8.0 Hz), 7.32−7.17 (m), 7.23−6.94 (m), 6.98−6.74 (m), 6.69 (d, J = 15.4 Hz), 2.19 (d, J = 3.9 Hz, 6H), 2.15 (d, J = 5.2 Hz, 6H), . 13C{1H} NMR (63 MHz, CDCl3) δ 156.22, 149.38, 148.07, 147.14, 145.26, 142.06, 141.18, 139.00, 138.35, 137.29, 136.81, 135.77, 135.43, 135.36, 134.45, 131.23, 130.98, 130.84, 130.69, 130.20, 130.17, 129.42, 128.55, 128.13, 126.89, 125.84, 125.69, 124.66, 124.59, 124.51, 123.18, 123.06, 122.89, 122.66, 77.67, 77.16, 76.65, 31.00, 29.77, 19.88, 19.43, 19.36. IR νmax/cm−1 (solid): 2932, 2921, 1583, 1560, 1530, 1499, 1471, 1435, 1348, 1260, 781, 742, 733, 720, 688. HRMS m/z [M+H]+ Calculated for C22H19BrN3O4: 468.0553; found 468.0545. (E)-4-Chloro-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline and (Z)-4-Chloro-N-(2-nitro-1-(4-nitrophenyl)vinyl)-N-phenylaniline (3ia). Prepared according to the general procedure from (Z)-4-chloroN-(2-nitro-1-(4-nitrophenyl)vinyl)aniline (160 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (83.0 mg, 0.210 mmol, 42%). Mp 202−203 °C; Rf = 0.30 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 8.38−7.97 (m, 2H), 7.62 (dd, J = 50.6, 8.4 Hz, 2H), 7.36−7.19 (m, 5H), 7.10 (d, J = 7.8 Hz, 2H), 7.04 (d, J = 7.8 Hz, 2H), 6.94−6.80 (m, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 156.3, 148.5, 143.9, 142.7, 139.3, 133.3, 131.0, 130.33, 130.31, 130.0, 129.9, 128.5, 127.8, 127.3, 126.5, 125.8, 125.1, 125.0, 124.3, 123.8. IR νmax/cm−1 (solid): 2920, 1559, 1519, 1340, 1254, 1090, 1015, 857, 744, 717, 698. HRMS m/z [M+H]+ Calculated for C20H15N3O4Cl: 396.0751; found 396.0749. (E)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-3,4-dimethyl-N-phenylaniline and (Z)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-3,4-dimethyl-Nphenylaniline (3ja). Prepared according to the general procedure from (Z)-N-(1-(4-chlorophenyl)-2-nitrovinyl)-3,4-dimethylaniline

(151 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 12 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (140 mg, 0.370 mmol, 74%). Mp 148−149 °C; Rf = 0.33 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.46 (d, J = 8.1 Hz, 1H), 7.33−7.18 (m, 5H), 7.17−6.95 (m, 4H), 6.91−6.77 (m, 2H), 6.76 (s, 1H), 2.17 (t, J = 9.8 Hz, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 158.5, 146.2, 144.7, 143.6, 142.4, 138.6, 137.9, 137.2, 136.1, 136.0, 134.5, 134.4, 131.5, 131.4, 131.1, 130.59, 130.58, 129.7, 129.40, 129.35, 128.8, 128.3, 127.4, 126.8, 126.2, 125.5, 124.8, 124.7, 124.6, 123.8, 122.7, 20.01, 19.98, 19.51, 19.46. IR νmax/ cm−1 (solid): 2920, 1552, 1492, 1340, 1290, 1250, 1090, 1014, 736, 716, 694. HRMS m/z [M+Na]+ Calculated for C22H19N2O2ClNa: 401.1033; found 401.1021. (E)-4-Chloro-N-(1-(4-chlorophenyl)-2-nitrovinyl)-N-phenylaniline and (Z)-4-Chloro-N-(1-(4-chlorophenyl)-2-nitrovinyl)-N-phenylaniline (3ka). Prepared according to the general procedure from (Z)-4chloro-N-(1-(4-chlorophenyl)-2-nitrovinyl)aniline (154 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (118 mg, 0.307 mmol, 61%). Mp 157−158 °C; Rf = 0.36 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.46 (d, J = 8.2 Hz, 1H), 7.32−7.26 (m, 4H), 7.25−7.18 (m, 4H), 7.14−7.04 (m, 2H), 6.99 (dd, J = 8.4, 4.9 Hz, 2H), 6.89 (s, 0.5H), 6.77 (s, 0.5H); 13C{1H} NMR (75 MHz, CDCl3) δ 165.5, 157.7, 151.3, 145.4, 144.6, 143.3, 137.7, 136.5, 133.6, 132.58, 131.40, 131.36, 131.1, 130.9, 130.2, 130.1, 129.8, 129.7, 129.6, 129.0, 128.5, 127.34, 127.28, 126.0, 125.9, 125.7, 125.1, 125.0. IR νmax/cm−1 (solid): 1584, 1558, 1487, 1301, 1279, 1255, 1090, 1013, 833, 695. HRMS m/z [M+H]+ Calculated for C20H15N2O2Cl2: 385.0511; found 385.0513. (E)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-4-nitro-N-phenylaniline and (Z)-N-(1-(4-Chlorophenyl)-2-nitrovinyl)-4-nitro-N-phenylaniline (3la). Prepared according to the general procedure from (Z)-N-(1-(4chlorophenyl)-2-nitrovinyl)-4-nitroaniline (160 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 24 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (112 mg, 0.284 mmol, 57%). Mp 146−147 °C; Rf = 0.32 (cyclohexane−ethyl acetate, 5:1). 1H NMR (300 MHz, CDCl3) δ 8.09 (dd, J = 16.7, 8.6 Hz, 2H), 7.49 (d, J = 8.1 Hz, 2H), 7.42−7.23 (m, 4H), 7.22−7.02 (m, 5H), 6.84 (s, 1H); 13C{1H} NMR (75 MHz, CDCl3) δ 151.7, 150.2, 143.9, 143.8, 138.4, 137.2, 132.6, 131.5, 131.0, 130.7, 130.1, 129.9, 129.3, 128.3, 128.2, 128.2, 127.4, 127.1, 126.4, 125.9, 125.5, 125.2, 125.1, 122.7. IR νmax/cm−1 (solid): 1586, 1510, 1487, 1339, 1303, 1274, 1110, 1091, 1012, 850, 752, 696. HRMS m/z [M+H]+ Calculated for C20H15N3O4Cl: 396.0746; found 396.0751. (E)-N-(2-Nitro-1-(p-tolyl)vinyl)-N-phenylaniline and (Z)-N-(2Nitro-1-(p-tolyl)vinyl)-N-phenylaniline (3ma). Prepared according to the general procedure from (Z)-N-(2-nitro-1-(p-tolyl)vinyl)aniline (127 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 5 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (80.0 mg, 0.242 mmol, 48%). Mp 163−164 °C; Rf = 0.34 (cyclohexane−ethyl acetate, 10:1). 1H NMR (300 MHz, CDCl3) δ 7.45 (d, J = 8.0 Hz, 1H), 7.35−7.21 (m, 5H), 7.17 (d, J = 7.2 Hz, 1H), 7.15−7.04 (m, 7H), 6.94 (s, 0.5H), 6.80 (s, 0.5H), 2.38−2.23 (m, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 159.7, 153.1, 146.1, 145.0, 141.7, 140.3, 132.4, 130.1, 130.0, 129.7, 129.6, 129.4, 129.2, 129.1, 127.3, 126.565, 125.3, 124.9, 124.7, 124.1, 21.6, 21.5. IR νmax/cm−1 (solid): 2920, 1580, 1560, 1490, 1300, 1270, 1221, 830, 757, 694. HRMS m/z [M+H]+ Calculated for C21H19N2O2: 331.1447; found 331.1449. (E)-3,4-Dimethyl-N-(2-nitro-1-(p-tolyl)vinyl)-N-phenylaniline and (Z)-3,4-Dimethyl-N-(2-nitro-1-(p-tolyl)vinyl)-N-phenylaniline (3na). Prepared according to the general procedure from (Z)-3,4-dimethylN-(2-nitro-1-(p-tolyl)vinyl)aniline (141 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 16 h. Purification of the crude product by column chromatography on silica gel afforded the product as an orange crystalline solid (146 mg, 0.408 mmol, 82%). 11762


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The Journal of Organic Chemistry Mp 175−176 °C; Rf = 0.29 (cyclohexane−ethyl acetate, 9:1). 1H NMR (300 MHz, CDCl3) δ 7.44 (d, J = 8.0 Hz, 1H), 7.24 (dd, J = 16.0, 7.6 Hz, 3H), 7.14−6.97 (m, 6H), 6.91 (d, J = 5.5 Hz, 1H), 6.86 (d, J = 7.3 Hz, 1H), 6.82 (d, J = 2.2 Hz, 0.3H), 6.77 (s, 0.7H), 2.32 (d, J = 6.2 Hz, 3H), 2.28−2.14 (m, 6H); 13C{1H} NMR (75 MHz, CDCl3) δ 156.0, 153.3, 146.4, 144.9, 143.8, 142.7, 141.5, 140.1, 138.3, 137.5, 135.6, 134.0, 132.7, 130.8, 130.3, 130.2, 129.9, 129.6, 129.5, 129.3, 129.1, 129.0, 128.1, 127.2, 126.2, 126.0, 125.1, 124.8, 124.5, 124.1, 123.5, 122.5, 21.6, 21.5, 19.9, 19.8, 19.4, 19.3. IR νmax/cm−1 (solid): 2918, 1556, 1489, 1377, 1294, 1266, 1019, 823, 761, 694. . HRMS m/z [M+H]+ Calculated for C23H23N2O2: 359.1760; found 359.1748. (E)-4-Chloro-N-(2-nitro-1-(p-tolyl)vinyl)-N-phenylaniline and (Z)4-Chloro-N-(2-nitro-1-(p-tolyl)vinyl)-N-phenylaniline (3oa). Prepared according to the general procedure from (Z)-4-chloro-N-(2nitro-1-(p-tolyl)vinyl)aniline (144 mg, 0.500 mmol) and phenyl(mesityl)iodonium trifluoromethanesulfonate for 20 h. Purification of the crude product by column chromatography on silica gel afforded the product as a yellow crystalline solid (106 mg, 0.291 mmol, 58%). Mp 166−167 °C; Rf = 0.33 (cyclohexane−ethyl acetate, 7:1). 1H NMR (300 MHz, CDCl3) δ 7.38 (dd, J = 28.6, 7.7 Hz, 2H), 7.30−7.18 (m, 4H), 7.17−7.06 (m, 5H), 7.05−6.97 (m, 2H), 6.95 (s, 0.6H), 6.78 (s, 0.4H), 2.33 (d, J = 5.3 Hz, 3H); 13C{1H} NMR (75 MHz, CDCl3) δ 159.1, 152.8, 145.7, 144.8, 144.7, 143.5, 142.0, 140.6, 131.9, 130.5, 130.0, 129.93, 129.86, 129.8, 129.7, 129.42, 129.36, 129.3, 129.1, 128.4, 127.1, 126.9, 125.8, 125.6, 125.1, 124.82, 124.75, 21.6, 21.5. IR νmax/cm−1 (solid): 2920, 1584, 1556, 1488, 1340, 1302, 1252, 1090, 1013, 826, 763, 695. . HRMS m/z [M+H]+ Calculated for C21H18N2O2Cl: 365.1057; found 365.1057.

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.joc.7b01591. Detailed results of the reaction optimization and NMR spectra for all compounds (PDF)

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AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected] *E-mail: [email protected] ORCID

Zoltán Novák: 0000-0001-5525-3070 Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS The financial support of the Hungarian Academy of Sciences (“Lendület” Research Scholarship; LP2012-48/2012). REFERENCES

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