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MOF-Derived Subnanometer Cobalt Catalyst for Selective C-H Oxidative Sulfonylation of Tetrahydroquinoxalines with Sodium Sulfinates Feng Xie, Guangpeng Lu, Rong Xie, Qinghua Chen, Huanfeng Jiang, and Min Zhang ACS Catal., Just Accepted Manuscript • DOI: 10.1021/acscatal.9b00037 • Publication Date (Web): 13 Feb 2019 Downloaded from http://pubs.acs.org on February 13, 2019
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ACS Catalysis
MOF-Derived Subnanometer Cobalt Catalyst for Selective C−H Oxidative Sulfonylation of Tetrahydroquinoxalines with Sodium Sulfinates Feng Xie, Guang-Peng Lu, Rong Xie, Qing-Hua Chen, Huan-Feng Jiang, and Min Zhang* Key Lab of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, People’s Republic of China ABSTRACT: The development and utilization of reusable base-metal catalysts is a central topic in catalysis. Herein, via a catalyst design strategy, we present the preparation of a highly dispersed and acid-resistant subnanometer cobalt catalyst (< 1nm) by a MOF-templated method, which has been utilized for selective C−H oxidative sulfonylation of tetrahydroquinoxalines with odorless sodium sulfinates. The transformation enables to generate a variety of sulfonylquinoxalines with the merits of good substrate and functional group compatibility, high regio and chemoselectivity, and the use of naturally abundant and reusable metal catalyst. The work presented offers the potential for further design of heterogeneous nanocatalysts, and fabrication of functional products that are difficult to prepare or inaccessible by homogeneous catalysis. KEYWORDS: MOF-templated method, ultrafine nanoparticles, cobalt, selective C–H sulfonylation, sulfonylquinoxalines
Selective introduction of a sulfonyl group into an organic molecule is of important significance in synthetic chemistry, as it enables to alter the charge distribution of the entire molecule, and result in enhanced hydrophilicity and biological affinity. These switched properties contribute to the development of new medicines and functional materials.1 Among various organosulfones, sulfonyl (hetero)arenes are of particular importance due to the extensive applications in biological and pharmaceutical chemistry,2a-b organic synthesis,2c-2d and material science.2e Conventionally, the synthesis of such compounds relies on the Friedel-Crafts sulfonylation of arenes with sulfonic acids3a-b or sulfonyl halides.3c-d In addition, the strategies, via the oxidation of sulfides,4 the cross-coupling of sulfinates or the SO2 surrogates with aryl halides,5 Suzuki-type reaction,6 and direct C−H sulfonylation,7 have also provided interesting alternatives to realize various synthetic purposes. Despite the significant utility, these transformations are mainly focused on the sulfonylation of aryl systems. Moreover, they suffer from the shortcomings such as difficult catalyst reusability, the use of corrosive acids and less eco-friendly oxidants, the need for preinstallation of directing groups and specific coupling agents, and harsh conditions. In this context, selective sulfonylation of heteroarenes with reusable catalysts, preferably earth-abundant metals, constitutes a new topic to be studied. Our efforts toward the functionalization of N-heterocycles8 and the interesting applications of sulfonylquinoxalines9 motivated us to introduce sulfonyl functionality into the quinoxalyl skeleton. Here, an envisioned synthetic protocol, via in situ capture of single electron oxidation (SEO)10 induced tetrahydroquinoxalyl radical by sulfonyl radical, is illustrated in Scheme 1. By employing the coupling of tetrahydroquinoxaline (THQX) 1 and odorless sodium sulfinate 2 as a prototypical example, the presence of a compatible catalyst (Cat.) and radical initiator (e.g., iodide
reagent) is expected to generate the N-radical 1-1 via SEO of the N-atom of THQX 1 and deprotonation (from 1 to 1-1), which then isomerizes to the aryl radical 1-2 due to the SOMO stabilized by the aryl ring. Similarly, the SEO of sulfinate 2 by iodide radical generates the electrophilic sulfonyl radical 2-1, which combines with iodide radical to form the reversible sulfonyl iodide (2-2). Then, the radical-radical coupling between 1-2 and 2-1 would yield the adduct 3’. Finally, the dehydroaromatization of 3’ would give rise to the C−H sulfonylation product 3. However, it is noteworthy that full dehydrogenation of THQX 1 to quinoxaline is thermodynamically favorable. Moreover, the radical coupling between 1-1 and 2-1, or the nucleophilic substitution between THQX 1 and 2-2 can generate sulfonamide 4.11 So, to achieve a chemoselective synthesis of sulfonylquinoxaline 3, two challenging issues have to be resolved: (1) The rate of para-aryl C−H sulfonylation should be much faster than the formation of sulfonamide 4. (2) The formation of non-coupling quinoxaline should be as slow as possible, thus favoring the cross-coupling of 1-2 and 2-1 to form intermediate 3’. [Cat.] / [O]
O R S O2
I
I
-
O S R O 2-1
H N
O
R'
+
N H
1
R'
-H+
I-
2-1
3
N
[Cat.] / [O] H N R'
2-1
1-2 N
Scheme 1. Envisioned new synthetic protocol
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N R'
N 4 H
H N 1-1 N
R O O R S S O N +
R'
2
I [Cat.] + [O]
RSO2Na
O I S R O 2-2
I
O R S O
H N R'
N 3' H
ACS Catalysis Based on the above information, we believed that, via a catalyst design strategy, the development of a low-loading cobalt nanocatalyst would provide a solution to achieve a chemoselective synthesis. On one hand, the cobalt metal has weak interacting ability with hard bases such as the N-atoms of THQXs. On the other hand, such type of heterogeneous catalyst has low density of active sites exposed on the solid surface. These two key factors would result in low oxidation efficiency toward THQXs, and favor the capture of transient intermediates by sodium sulfinates 2. In recent years, metal-organic frameworks (MOFs) as the precursors have been elegantly employed to develop various nanomaterials supported on N-doped carbon.12 Interestingly, such a method enables to afford the desired materials with high specific surface areas, abundant micropores, and controllable coordination environment of metal with heteroatoms.13 Attracted by the natural abundance and the capability toward dehydrogenation of cobalt,14 and the distinct reactivity of tiny metal clusters,15 we wish herein to report the development of a new subnanometer cobalt catalyst via a MOF-templated method, and describe its utility toward the first para-aryl C−H sulfonylation of THQXs with sodium sulfinates. The catalyst was prepared through pyrolysis of the MOF precursors immobilized on the commercially available carbon powder.16 First, the assembly of ZIF-8 framework was performed in methanol by introducing Zn(NO3)2 and organic linker 2-methylimidazole (MeIm). After that, Co precursor was introduced into the pores of ZIF-8 via double-solvent impregnating method. Then, the in situ generated MOF-Co– ZIF–8 was deposited on the carbon support (Vulcan XC-72R). Further pyrolysis of the resulting material at 1000 °C for 2 h under argon flow produced the N-doped carbon-supported subnanometer cobalt catalyst (denoted as Co–N–C, see supporting information (SI) for details). The XRD analysis of the catalyst (Figure S1 in the SI) only discloses the characteristic peaks of graphitic carbon, and the peaks assigned to cobalt are not observed, suggesting that the Co species are either amorphous or highly dispersed. The N2 adsorption–desorption measurements (BET) of the catalyst clearly present a typical IV isotherm with hysteresis loop (Figure S2), indicating a hierarchically micro-mesoporous structure. Moreover, the specific surface area is detected as 286 m2g-1, and the relevant distribution curve of the pore diameter displays that the dominant micropores are centered at 0.58 nm and 1.08-1.77 nm, and the regions at 2.62-3.42 nm and 8.30-9.90 nm are ascribed to typical mesopores. Such a micro-mesoporous structure is beneficial to mass transfer, and exposes sufficiently active catalytic sites. The morphology and size distribution of the prepared material were further studied by TEM, HRTEM, and EDS. The images in Figure 1a and Figure S3a of SI show the existence of graphite carbon layers, but fail to observe any larger cobalt nanoparticulates, which is in consistent with the XRD results. In Figure 1, the bright field (BF) TEM image (Figure1b), and high-angle annular dark-field scanning TEM (HAADF-STEM) image (Figure1c, and Figure S3d, SI) further demonstrate that the cobalt species are uniformly dispersed. The average diameter of Co particles is 0.40 ± 0.08 nm (Figure S4a). Meanwhile, as shown in the elemental mapping images (Figure 1c, and Figure S5a-5f), the signals of Co, N and C overlap completely, implying that the cobalt is embedded in the N-doped carbon by bonding with the N-atom,
which prevents the agglomeration of the dispersed cobalt particles.
b
a
10 nm 2 nm
BF
10 nm
2 nm
d
c
10 nm
10 nm Figure 1. (a) HR-TEM image and Bright field (BF) TEM image (b) of Co–N–C. (c) HAADF-STEM image of Co–N–C. (d) The corresponding EDS elemental maps of Co, N, O, C.
27000
N 1s
Raw Sum Co-N-C Pyrrolic N Graphitic N oxidizedN
26500 26000
Counts / s
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
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25500 25000 24500 24000 23500 23000 392
394
396
398
400
402
404
406
Binding energy/ eV
408
410
Figure 2. N1s XPS spectra of Co–N–C.
X-ray photoelectron spectroscopy (XPS) was then employed to investigate the surface chemistry of the prepared material. The element contents are as follows: Co (1.14 wt %), N (1.41 wt %), O (22.45 wt %), and C (75 wt %), and no residue Zn is detected as it has been evaporated (> 907 °C) during the pyrolysis process. Furthermore, an ultralow Co loading was confirmed by ICP-OES (0.88 wt%). The N 1s spectrum (Figure 2) can be deconvoluted into four peaks with Co–N–C (399.0 eV), pyrrolic N (400.01 eV), gra phitic-N (401.31 eV), and N-oxide species (403.56 eV).17a-b The graphitic-N and N-oxide derives from the graphitization of uncoordinated nitrogen-containing organic linker, while the Co–N–C structure originates from the graphitization of the coordinative Co–ZIF–8. Similarly, the Co 2p spectrum (Figure S6) shows the characteristic peak of Co2+ species with a binding energy of 780.7 ev, which is further confirmed by the corresponding satellite peaks at 786.9 ev and 802.8 ev,17c the peak with 2
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ACS Catalysis typical binding energy of 796.5 eV of the Co 2p1/2 electrons is ascribed to Co3O4.17d With the availability of the ultrafine nanomaterial, we subsequently evaluated its catalytic performance toward the benchmark reaction of 1,2,3,4-tetrahydroquinoxaline 1a and sodium benzenesulfinate 2a. Various reaction parameters, involving the effect of catalysts, iodide-containing additives, temperatures, and reaction mediums were screened (Table S1). The highest GC yield of product 3aa (85%) and the best chemoselectivity were obtained when the reaction in DMF charged with a O2 balloon was performed at 60 °C for 16 h by using 2.5 mol% of Co–N–C, and 1.2 equiv of ammonium iodide (standard conditions, entry 16 of Table S1). Further, we compared the catalytic performance of this newly developed catalyst with other relevant materials with the model reaction, including various homogeneous catalysts (Table 1, entries 1-5) and MOF-derived nanocatalysts (Table 1, entries 6-9). The results show that Co–N–C exhibits the best activity (entry 10). Table 1. Comparison on the Catalytic Performance of the New Catalyst and Other Relevant Systems H N
N + PhSO2Na
N 1a H
2a
Catalyst (2.5 mol%) NH4I (1.2 eq), 60 oC,16 h
O S Ph O
N 3aa
3aa Yield %a Entry Catalyst 2 1 [Cp*IrCl2]2 3 2 [Ru(p-cymene)Cl2]2 3 Pd(OAc)2 3 7 4 Co2(CO)8 12 5 Cp*Co(CO)I2 32b 6 Co-DABCO-TPA@C-800 58 7 Co-ZIF8 68c 8 Co-ZrO2/N-C 15d 9 Ru SAS/N-C 85 (this work) 10 Co-N-C aUnless otherwise stated, all reactions were performed at 60 °C for 16 h under 1 atm of O2 atmosphere (using O2 balloon) by using 1a (1.2 eq, 0.3 mmol), 2a (0.25 mmol), catalyst (2.5 mol %), DMF (1.5 mL), ammonium iodide (1.2 eq, 0.3 mmol), temperature (60 °C), GC yield using hexadecane as an internal standard. b,c,dThe catalysts were prepared according to the references 12e，8a, and 12b, respectively.
With the optimal conditions established, we next tested the substrate scope of the sulfonylation reaction. Initially, the coupling of THQX 1a with various sodium arylsulfinates 2 (2a-2j, see Scheme S1 for substrate information) were explored. As shown in Scheme 2, all the reactions underwent efficient sulfonylation at the site para to the N-atom of THQX 1a, delivering the desired products in moderate to good isolated yields (see 3aa-3aj). The structure of product 3aa was identified by single-crystal X-ray diffraction (See Table S4 in SI). It was found that a range of functionalities (i.e., −Me, −OMe, −CF3, −F, −Cl and −Br) on the aryl ring of sodium sulfinates 2 were well tolerated, and these substituents had little influence on the product formation. In addition, sodium heteroarylsulfinates (2k-2n) and alkylsulfinates (2o-2q) were also proven to be compatible agents to react with THQX 1a, generating the 6-heteroarylsulfonyl and 6-alkylsulfonyl quinoxalines (3ak-3aq) in moderate to high yields upon isolation.
H N + R1SO2Na
N H
1a
Co-N-C (2.5 mol%), DMF, O2 o
NH4I (1.2 eq), 60 C,16 h
2 N
O S O
N 3aa,80%
Ph
N
N O S N O 3ac,75% N
F
N
N
N
N
O S N O 3ah, 68%
Br
O S N O 3ai, 70%
O S O
N
N
3ae, 54%
3ag, 47%
Cl
O S O
N
N
N O S O
N N
3aj, 73%
N
MeO N
3ad, 68%
F3C
N
O S N O 3af, 65%
O S O
F
3
O S N O 3ab,63% N
O S O
N O S R1 O
N
3ak,78%
N
N
O S N O 3am,38%
O S N O 3an, 61%
N O
N O S N O 3ao, 67% N
N O S N O 3ap, 65%
O S N O S 3al, 71%
O S N O 3aq, 84%
Scheme 2. Variation of Sodium Sulfinates. Subsequently, we focused on the variation of both coupling partners. As listed in Scheme 3, various combinations of THQXs 1 bearing different functional groups (−Me, and −Cl, −Br, ester) with a series of sodium sulfinates 2 were tested. Similar to the outcomes illustrated in Scheme 2, all the substrates underwent smooth dehydrogenative cross-coupling, affording the sulfonylquinoxalines in a regioselective manner. Notably, the substituents on the aryl ring of THQXs 1 significantly influenced the product yields. In particular, electron-donating groups can give the products (3ba-3ca) in higher yields than those of electron-withdrawing ones (3ea-3ga). Such a phenomenon is attributed to the electron-rich groups enhancing the electron-density of the N-atoms in THQXs, thus favoring the oxidation process to form more stable aryl radicals (Scheme 1, see intermediate 1-2). In addition, the reactions of unsymmetrical THQX 1d with sulfinates 2a and 2q produced two groups of regioisomers in the ratios of 43 : 57 and 45 : 55, respectively (3da and 3da’, 3dq and 3dq’). Similarly, THQX 1e containing an electron-withdrawing ester group also was able to couple with sulfinate 2a, generating two isomers (3ea : 3ea’) in a ratio of 41 : 59. These three examples demonstrate that the reaction utilizing unsymmetrical THQXs has no specific regioselectivity.
3
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ACS Catalysis R2
H N R
2
R SO2Na
+
O S Ph O
Co-N-C (2.5 mol%), DMF, O2
1
NH4I (1.2 eq), 60 oC, 16 h
2
N H
1
N
N
N
O S N O 3bc, 75%
3ba, 86%
MeO
N
O S 1 R O
N
O S O
N O
N O S O
N 3bj, 78%
F3C
N O S N O 3bq, 82%
N 3bn, 72%
N
N
N
O S N O 3ca, 58%
O S O
Ph
O O S N + S Ph Ph O O (3da + 3da'), 56% (43 : 57)
3cq, 50%
N 3cn, 41%
N O S O
N
N
O N + S N O (3dq + 3dq'), 51% (45 : 55) N
CO2Et
N
O S O
N O
N
N
N
O S + N Ph (3ea + 3ea'), 37% O
O S Ph O
N
3
N
N O S N O 3bk,74%
N
CO2Et
(41 : 59) Cl
Br
N
N
O S N Ph O 3ga, 41%
O S N Ph O 3fa, 43%
Scheme 3. Variation of Both Coupling Partners
100 3aa
80
GC Yield (%)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
60 40
0
slight deactivation of the catalyst. Further, we conducted acid leaching experiments to discriminate CoOx and Co−Nx as catalytic centers. The fresh catalyst treated with sulfuric acid still exhibited excellent catalytic efficiency (Figure S7), implying that the developed catalyst material is acid-resistant. Moreover, the present control experiment and the characterization of N1s XPS spectrum suggest that the Co−Nx species embedded in the carbon sheets serve as the catalytically active sites. To gain insights into the reaction mechanism, we performed several control experiments (Scheme 4). First, the reaction of 1a and 2a under the standard conditions was terminated after 2 h. Except for product 3aa detected in 18% yield, 6-sulfonyl tetrahydroquinoxaline 3aa’ and quinoxaline 1a’ were detected in 45% and 15% yields, respectively (eq.1). Meanwhile, the time-yield profile of the same reaction was depicted in Figure S8, compound 3aa’ accumulated to a maximum content within the first 2 hours, and then gradually consumed in the left 14 hours. Further, the reaction of 1a’ and 2a was unable to yield product 3aa (eq.2). Treating substrate 1a under the standard condtions produced 1a’ in almost quantitative yield, and no 6-iodoquinoxaline was detected. The results show that 3aa’ is a crucial intermediate. Further, the reaction of freshly prepared benzenesulfonyl iodide 2-2a18 with 1a only resulted in trace of product 3aa (eq.3), implying that an electrophilic sulfonylation is less likely. The addition of excess TEMPO, 2,6-di-tert-butyl-4-methylphenol (BHT), or benzoquinone (BQ) into the reaction of 1a and 2a significantly suppressed the product formation (eq.4). The product of 1,1-diphenylethylene trapping a sulfonyl group was determined by HR-MS (eq.5), which suggests that, at least, the reaction involves sulfonyl radical. Moreover, in consideration that the sulfonyl unit can be reduced to sulfur group,7d the para-aryl C−H sulfuration of 1a with 2a to 6-(phenylthio)quinoxaline 3aa’’ followed by the oxidation of sulfur atom might offer another way to give product 3aa. However, subjection of 3aa’’to the standard conditions failed to yield 3aa (eq.6). Thus, such a pathway can be ruled out. These control experiments are well consistent with the proposed pathway in Scheme 1. 1a
20
0
1
2 3 Recycle number
4
5
Figure 3. Reuse of the Co–N–C catalysts.
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+ 2a
1a'
+
1a
+
standard PhO2S conditions 2h
N
H N
PhO2S
N 3aa, 18%
+
N 3aa', 45% H
standard conditions
2a
N +
(1) N 1a', 15%
3aa, 0%
(2)
SO2I standard conditions
3aa, trace + 1a', 86%
(3)
2-2a
To check the reusability of the developed Co–N–C catalyst, it was recycled to run the model reaction for additional 5 consecutive times. As shown in Figure 3, the catalytic activity and reaction selectivity remained very well, albeit with a slight decrease of yield, which demonstrates the high durability of this catalyst. After five recyclings, the Co content slightly decreased from 0.88 wt% to 0.71 wt% (ICP-OES analysis). Meanwhile, the HRTEM images and HAADF-STEM images (Figure S3e-3h, SI) of the reused catalyst show that there are no obvious Co cluster aggregation during the reaction. The mean particle size of the used catalyst is 0.72 ± 0.19 nm (Figure S4b), which is close to the fresh one and still maintains the subnanometer scale. The nanoparticle leaching during the process of mechanical abrasion accounts for the
1a
+
2a
1a
+
2a
standard conditions
standard conditions Ph2C CH2 (3 equiv)
S
N
3aa''
N
TEMPO (1 equiv), 3aa, 36% TEMPO (5 equiv), 3aa, 3% (4) BHT (3 equiv), 3aa, 12% BQ (3 equiv), 3aa, 0% 3aa, 26% (5) + Ph2C CHSO2Ph HR-MS: [M+1]=321.0946
standard conditions
3aa, 0%
(6)
Scheme 4. Control Experiments Finally, we were interested in demonstrating the utility of the developed chemistry. The sulfonylation reaction was successfully applied for rapid synthesis of 4
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ACS Catalysis 6-(phenylsulfonyl)-1,4-dihydroquinoxaline-2,3-dione 4aa, an analogue of potent AMPA receptor antagonist.19 As shown in Scheme 5, under the standard conditions, the coupling of substrates 1a and 2a was scaled up to 5 mmol, which enabled gram-scale synthesis of compound 3aa with high isolated yield (75%). Then, the treatment of compound 3aa with hypervalent iodinane agent (BTI) afforded product 4aa in 68% yield.20 Moreover, the bromination of 3aa with N-bromosuccinimide gave compound 5aa-1 in 74% yield in H2SO4.21a Then, the C-N coupling between 5aa-1 and 4-methoxyaniline under palladium catalysis afforded product 5aa-2 in 81% yield.21b This example shows the potential of the obtained products in the fabrication of complex sulfonylquinoxalines via further transformations. O H Ph O 1a Ph N S N S (5 mmol) standard O Oxidant BTI + conditions O N 2a N MeCN / H2O=3:1 H r.t., 24h (5 mmol) 3aa, 75%(1.02g) 4aa, 68%
NH2 O S O
N N
O
OMe
NBS, H2SO4 80℃ ,16h
Br
O
MeO Pd2(dba)3, P(t-Bu)3 t-BuONa, toluene
5aa-1, 74%
HN O S O 5aa-2, 81%
N N
Scheme 5. Synthetic Utility. In summary, via a catalyst design strategy, we have developed a new subnanometer cobalt catalyst with the features of high dispersion and acid-resistance, it exhibits good catalytic performace toward the first selective C−H oxidative sulfonylation of tetrahydroquinoxalines with odorless sodium sulfinates. The catalytic transformation enables to generate a variety of sulfonylquinoxalines with the merits of good functional tolerence, broad substrate scope, excellent regio and chemoselectivity, and the use of naturally abundant and reusable cobalt catalyst. The present work offers the potential for futher design of heterogeneous nanocatalysts, and synthesis of functional molecules that are difficult to prepare or inaccessible with homogeneous catalysis.
ASSOCIATED CONTENT Supporting Information The Supporting Information is available free of charge on the ACS Publications website at DOI: The detail of catalyst preparation, more characterization results, complete experimental procedures and spectral data (PDF)
AUTHOR INFORMATION Corresponding Author *
[email protected] Notes The authors declare no competing financial interests.
ACKNOWLEDGMENT We thank the National Key Research and Development Program of China (2016YFA0602900), National Natural Science Foundation of China (21472052), Science and Technology Program of GuangZhou (201607010306), Science Foundation for Distinguished Young Scholars of Guangdong (2014A030306018) for financial support.
REFERENCES (1) (a) Li, P.; Hu, D.; Xie, D.; Chen, J.; Jin, L.; Song, B. Design, Synthesis, and Evaluation of New Sulfone Derivatives Containing a 1,3,4-Oxadiazole Moiety as Active Antibacterial Agents. J. Agric. Food Chem. 2018, 66, 3093-3100. (b) Hermann, M.; Wu, R.; Grenz, D. C.; Kratzert, D.; Li, H.; Esser, B. Thioether- and Sulfone-Functionalized Dibenzopentalenes as n-Channel Semiconductors for Organic Field-Effect Transistors. J. Mater. Chem. C 2018, 6, 5420-5426. (c) Feng, M. H.; Tang, B. Q.; Liang, S. H.; Jiang, X. F. Sulfur Containing Scaffolds in Drugs: Synthesis and Application in Medicinal Chemistry. Curr. Top. Med. Chem. 2016, 16, 1200-1216. (2) (a) Alavi, S.; Mosslemin, M. H.; Mohebat, R.; Massah, A. R. Green Synthesis of Novel Quinoxaline Sulfonamides with Antibacterial Activity. Res. Chem. Intermed. 2017, 43, 4549-4559. (b) Barrett, T. D.; Lagaud, G.; Wagaman, P.; Freedman, J. M.; Yan, W.; Andries, L.; Rizzolio, M. C.; Morton, M. F.; Shankley, N. P. The Cholecystokinin CCK2 Receptor Antagonist, JNJ-26070109, Inhibits Gastric Acid Secretion and Prevents Omeprazole-Induced Acid Rebound in the Rat. Br. J. Pharmacol. 2012, 166, 1684-1693. (c) Ikeda, Y.; Ueno, R.; Akai, Y.; Shirakawa, E. α-Arylation of Alkylamines with Sulfonylarenes through a Radical Chain Mechanism. Chem. Commun. 2018, 54, 10471-10474. (d) Okumura, S.; Nakao, Y. Para-Selective Alkylation of Sulfonylarenes by Cooperative Nickel/Aluminum Catalysis. Org. Lett. 2017, 19, 584-587. (e) Li, C.; Li, Z.; Liu, J. G.; Zhao, X. G.; Yang, H. X.; Yang, S. Y. Synthesis and Characterization of Organo-Soluble Thioether-Bridged Polyphenylquinoxalines with Ultra-High Refractive Indices and Low Birefringences. Polymer 2010, 51, 3851-3858. (3) (a) Parvanak Boroujeni, K. Sulfonylation of Aromatic Compounds with Sulfonic Acids Using Silica Gel-Supported AlCl3 as a Heterogeneous Lewis Acid Catalyst. J. Sulfur Chem. 2010, 31, 197-203. (b) Graybill, B. M. Synthesis of Aryl Sulfones. J. Org. Chem. 1967, 32, 2931-2933. (c) Alexander, M. V.; Khandekar, A. C.; Samant, S. D. Sulfonylation Reactions of Aromatics Using FeCl3-Based Ionic Liquids. J. Mol. Catal. A: Chem. 2004, 223, 75-83. (d) Répichet, S.; Le Roux, C.; Hernandez, P.; Dubac, J.; Desmurs, J. R. Bismuth(III) Trifluoromethanesulfonate: An Efficient Catalyst for the Sulfonylation of Arenes. J. Org. Chem. 1999, 64, 6479-6482. (4) (a) Mirfakhraei, S.; Hekmati, M.; Eshbala, F. H.; Veisi, H. Fe3O4/PEG-SO3H as a Heterogeneous and Magnetically-Recyclable Nanocatalyst for the Oxidation of Sulfides to Sulfones or Sulfoxides. New J. Chem. 2018, 42, 1757-1761. (b) Guilbaud, J.; Labonde, M.; Selmi, A.; Kammoun, M.; Cattey, H.; Pirio, N.; Roger, J.; Hierso, J.-C. Palladium-Catalyzed Heteroaryl Thioethers Synthesis Overcoming Palladium Dithiolate Resting States Inertness: Practical Road to Sulfones and NH-Sulfoximines. Catal. Commun. 2018, 111, 52-58. (c) Martin, B.; Sedelmeier, J.; Bouisseau, A.; Fernandez-Rodriguez, P.; Haber, J.; Kleinbeck, F.; Kamptmann, S.; Susanne, F.; Hoehn, P.; Lanz, M.; Pellegatti, L.; Venturoni, F.; Robertson, J.; Willis, M. C.; Schenkel, B. Toolbox Study for Application of Hydrogen Peroxide as a Versatile, Safe and Industrially-Relevant Green Oxidant in Continuous Flow Mode. Green Chem. 2017, 19, 1439-1448. (d) Pritzius, A. B.; Breit, B. Asymmetric Rhodium-Catalyzed Addition of Thiols to Allenes: Synthesis of Branched Allylic Thioethers and Sulfones. Angew. Chem. Int. Ed. 2015, 54, 3121-3125. (5) (a) Yue, H.; Zhu, C.; Rueping, M. Cross-Coupling of Sodium Sulfinates with Aryl, Heteroaryl, and Vinyl Halides by Nickel/Photoredox Dual Catalysis. Angew. Chem. Int. Ed. 2018, 57, 1371-1375. (b) Liu, N.-W.; Liang, S.; Margraf, N.; Shaaban, S.; Luciano, V.; Drost, M.; Manolikakes, G. Nickel-Catalyzed Synthesis of Diaryl Sulfones from Aryl Halides and Sodium Sulfinates. Eur. J. Org. Chem. 2018, 2018, 1208-1210. (c) Liu, N. W.; Hofman, K.; Herbert, A.; Manolikakes, G.
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(6)
(7)
(8)
(9)
(10)
Visible-Light Photoredox/Nickel Dual Catalysis for the Cross-Coupling of Sulfinic Acid Salts with Aryl Iodides. Org. Lett. 2018, 20, 760-763. (d) Von Wolff, N.; Char, J.; Frogneux, X.; Cantat, T. Synthesis of Aromatic Sulfones from SO2 and Organosilanes under Metal-Free Conditions. Angew. Chem. Int. Ed. 2017, 56, 5616-5619. (e) Chen, Y.; Willis, M. C. Copper(I)-Catalyzed Sulfonylative Suzuki-Miyaura Cross-Coupling. Chem. Sci. 2017, 8, 3249-3253. (a) Hu, F.; Lei, X. Synthesis of Diaryl Sulfones at Room Temperature: Cu-Catalyzed Cross-Coupling of Arylsulfonyl Chlorides with Arylboronic Acids. ChemCatChem 2015, 7, 1539-1542. (b) Bandgar, B. P.; Bettigeri, S. V.; Phopase, J. Unsymmetrical Diaryl Sulfones through Palladium-Catalyzed Coupling of Aryl Boronic Acids and Arylsulfonyl Chlorides. Org. Lett. 2004, 6, 2105-2108. (a) Qiu, G.; Zhou, K.; Wu, J. Recent Advances in the Sulfonylation of C–H Bonds with the Insertion of Sulfur Dioxide. Chem. Commun. 2018, 54, 12561-12569. (b) Zhou, K.; Zhang, J.; Lai, L.; Cheng, J.; Sun, J.; Wu, J. C–H Bond Sulfonylation of Anilines with the Insertion of Sulfur Dioxide under Metal-Free Conditions. Chem. Commun. 2018, 54, 7459-7462. (c) Xia, H.; An, Y.; Zeng, X.; Wu, J. Palladium-Catalyzed Direct Sulfonylation of C–H Bonds with the Insertion of Sulfur Dioxide. Chem. Commun. 2017, 53, 12548-12551. (d) Guo, Y. J.; Lu, S.; Tian, L. L.; Huang, E. L.; Hao, X. Q.; Zhu, X.; Shao, T.; Song, M. P. Iodine-Mediated Difunctionalization of Imidazopyridines with Sodium Sulfinates: Synthesis of Sulfones and Sulfides. J. Org. Chem. 2018, 83, 338-349. (e) Xiao, F.; Chen, H.; Xie, H.; Chen, S.; Yang, L.; Deng, G. J. Iodine-Catalyzed Regioselective 2-Sulfonylation of Indoles with Sodium Sulfinates. Org. Lett. 2014, 16, 50-53. (a) Xie, F.; Chen, Q.-H.; Xie, R.; Jiang, H.-F.; Zhang, M. MOF-Derived Nanocobalt for Oxidative Functionalization of Cyclic Amines to Quinazolinones with 2-Aminoarylmethanols. ACS Catal. 2018, 5869-5874. (b) Liang, Y.; Jiang, H.; Tan, Z.; Zhang, M. Direct α-C-H Amination Using Various Amino Agents by Selective Oxidative Copper Catalysis: A Divergent Access to Functional Quinolines. Chem. Commun. 2018, 54, 10096-10099. (c) Chen, X.; Zhao, H.; Chen, C.; Jiang, H.; Zhang, M. Transfer Hydrogenative Para-Selective Aminoalkylation of Aniline Derivatives with N-Heteroarenes Via Ruthenium/Acid Dual Catalysis. Chem. Commun. 2018, 54, 9087-9090. (d) Chen, X.; Zhao, H.; Chen, C.; Jiang, H.; Zhang, M. Iridium-Catalyzed Dehydrogenative α-Functionalization of (Hetero)Aryl-Fused Cyclic Secondary Amines with Indoles. Org. Lett. 2018, 20, 1171-1174. (e) Chen, X. W.; Zhao, H.; Chen, C. L.; Jiang, H. F.; Zhang, M. Hydrogen-Transfer-Mediated α-Functionalization of 1,8-Naphthyridines by a Strategy Overcoming the over-Hydrogenation Barrier. Angew. Chem. Int. Ed. 2017, 56, 14232-14236. (f) Xie, F.; Xie, R.; Zhang, J. X.; Jiang, H. F.; Du, L.; Zhang, M. Direct Reductive Quinolyl β-C–H Alkylation by Multispherical Cavity Carbon-Supported Cobalt Oxide Nanocatalysts. ACS Catal. 2017, 7, 4780-4785. (a) Ibrahim, M. K.; Eissa, I. H.; Abdallah, A. E.; Metwaly, A. M.; Radwan, M. M.; ElSohly, M. A. Design, Synthesis, Molecular Modeling and Anti-Hyperglycemic Evaluation of Novel Quinoxaline Derivatives as Potential PPARγ and SUR Agonists. Bioorg. Med. Chem. 2017, 25, 1496-1513. (b) Bhati, S. In Silico Evaluation of Inhibitory Potential of Sulfonamide Derivatives against Diadenosine Tetraphosphate Hydrolase as Antimalarial Agents. Asian J. Pharm. 2017, 11, S47-S52. (c) Zhou, J.; Ba, M.; Wang, B.; Zhou, H.; Bie, J.; Fu, D.; Cao, Y.; Xu, B.; Guo, Y. Synthesis and Biological Evaluation of Novel Quinoxalinone-Based HIV-1 Reverse Transcriptase Inhibitors. Med. Chem. Commun. 2014, 5, 441-444. Liang, T.; Tan, Z.; Zhao, H.; Chen, X.; Jiang, H.; Zhang, M. Aerobic Copper-Catalyzed Synthesis of Benzimidazoles from Diaryl- and Alkylamines Via Tandem Triple C–H Aminations. ACS Catal. 2018, 8, 2242-2246.
Page 6 of 8
(11) (a) Yang, K.; Ke, M.; Lin, Y.; Song, Q. Sulfonamide Formation from Sodium Sulfinates and Amines or Ammonia under Metal-Free Conditions at Ambient Temperature. Green Chem. 2015, 17, 1395-1399. (b) Wei, W.; Liu, C.; Yang, D.; Wen, J.; You, J.; Wang, H. Metal-Free Direct Construction of Sulfonamides via Iodine-Mediated Coupling Reaction of Sodium Sulfinates and Amines at Room Temperature. Adv. Synth. Catal. 2015, 357, 987-992. (12) (a) Zhang, H.; Hwang, S.; Wang, M.; Feng, Z.; Karakalos, S.; Luo, L.; Qiao, Z.; Xie, X.; Wang, C.; Su, D.; Shao, Y.; Wu, G. Single Atomic Iron Catalysts for Oxygen Reduction in Acidic Media: Particle Size Control and Thermal Activation. J. Am. Chem. Soc. 2017, 139, 14143-14149. (b) Wang, X.; Chen, W.; Zhang, L.; Yao, T.; Liu, W.; Lin, Y.; Ju, H.; Dong, J.; Zheng, L.; Yan, W.; Zheng, X.; Li, Z.; Wang, X.; Yang, J.; He, D.; Wang, Y.; Deng, Z.; Wu, Y.; Li, Y. Uncoordinated Amine Groups of Metal–Organic Frameworks to Anchor Single Ru Sites as Chemoselective Catalysts toward the Hydrogenation of Quinoline. J. Am. Chem. Soc. 2017, 139, 9419-9422. (c) Lai, Q.; Zheng, L.; Liang, Y.; He, J.; Zhao, J.; Chen, J. Metal– Organic-Framework-Derived Fe-N/C Electrocatalyst with Five-Coordinated Fe-Nx Sites for Advanced Oxygen Reduction in Acid Media. ACS Catal. 2017, 7, 1655-1663. (d) Ji, S.; Chen, Y.; Fu, Q.; Chen, Y.; Dong, J.; Chen, W.; Li, Z.; Wang, Y.; Gu, L.; He, W.; Chen, C.; Peng, Q.; Huang, Y.; Duan, X.; Wang, D.; Draxl, C.; Li, Y. Confined Pyrolysis within Metal-Organic Frameworks to Form Uniform Ru3 Clusters for Efficient Oxidation of Alcohols. J. Am. Chem. Soc. 2017, 139, 9795-9798. (e) Jagadeesh, R. V.; Murugesan, K.; Alshammari, A. S.; Neumann, H.; Pohl, M.-M.; Radnik, J.; Beller, M. MOF-Derived Cobalt Nanoparticles Catalyze a General Synthesis of Amines. Science 2017, 358, 326-332. (f) Yin, P.; Yao, T.; Wu, Y.; Zheng, L.; Lin, Y.; Liu, W.; Ju, H.; Zhu, J.; Hong, X.; Deng, Z.; Zhou, G.; Wei, S.; Li, Y. Single Cobalt Atoms with Precise N-Coordination as Superior Oxygen Reduction Reaction Catalysts. Angew. Chem. Int. Ed. 2016, 55, 10800-10805. (13) Shen, K.; Chen, X.; Chen, J.; Li, Y. Development of MOF-Derived Carbon-Based Nanomaterials for Efficient Catalysis. ACS Catal. 2016, 6, 5887-5903. (14) (a) Li, J.; Liu, G.; Long, X.; Gao, G.; Wu, J.; Li, F. Different Active Sites in a Bifunctional Co@N-Doped Graphene Shells Based Catalyst for the Oxidative Dehydrogenation and Hydrogenation Reactions. J. Catal. 2017, 355, 53-62. (b) Xu, S.; Zhou, P.; Zhang, Z.; Yang, C.; Zhang, B.; Deng, K.; Bottle, S.; Zhu, H. Selective Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid Using O2 and a Photocatalyst of Co-thioporphyrazine Bonded to g-C3N4. J. Am. Chem. Soc. 2017, 139, 14775-14782. (c) Deibl, N.; Kempe, R. General and Mild Cobalt-Catalyzed C-Alkylation of Unactivated Amides and Esters with Alcohols. J. Am. Chem. Soc. 2016, 138, 10786-10789. (15) (a) Liu, L.; Corma, A. Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles. Chem. Rev. 2018, 118, 4981-5079. (b) Zhou, P.; Jiang, L.; Wang, F.; Deng, K.; Lv, K.; Zhang, Z. High Performance of a Cobalt–Nitrogen Complex for the Reduction and Reductive Coupling of Nitro Compounds into Amines and Their Derivatives. Sci. Adv. 2017, e1601945. (c) Kang, X.; Liu, H.; Hou, M.; Sun, X.; Han, H.; Jiang, T.; Zhang, Z.; Han, B. Synthesis of Supported Ultrafine Non-Noble Subnanometer-Scale Metal Particles Derived from Metal-Organic Frameworks as Highly Efficient Heterogeneous Catalysts. Angew. Chem. Int. Ed. 2016, 55, 1080-1084. (d) Jiang, K.; Zhao, D.; Guo, S.; Zhang, X.; Zhu, X.; Guo, J.; Lu, G.; Huang, X. Efficient Oxygen Reduction Catalysis by Subnanometer Pt Alloy Nanowires. Sci. Adv. 2017, 3, e1601705. (e) Vilar-Vidal, N.; Rivas, J.; López-Quintela, M. A. Size Dependent Catalytic Activity of Reusable Subnanometer Copper(0) Clusters. ACS Catal. 2012, 2, 1693-1697. (f) Okamoto, K.; Akiyama, R.; Yoshida, H.; Yoshida, T.; Kobayashi, S. Formation of Nanoarchitectures Including
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ACS Catalysis
(16)
(17)
(18)
(19)
(20)
(21)
Subnanometer Palladium Clusters and Their Use as Highly Active Catalysts. J. Am. Chem. Soc. 2005, 127, 2125-2135. Zhao, C.; Dai, X.; Yao, T.; Chen, W.; Wang, X.; Wang, J.; Yang, J.; Wei, S.; Wu, Y.; Li, Y. Ionic Exchange of Metal-Organic Frameworks to Access Single Nickel Sites for Efficient Electroreduction of CO2. J. Am. Chem. Soc. 2017, 139, 8078-8081. (a) Liu, W.; Zhang, L.; Yan, W.; Liu, X.; Yang, X.; Miao, S.; Wang, W.; Wang, A.; Zhang, T. Single-Atom Dispersed Co-N-C Catalyst: Structure Identification and Performance for Hydrogenative Coupling of Nitroarenes. Chem. Sci. 2016, 7, 5758-5764. (b) Zhang, L.; Wang, A.; Wang, W.; Huang, Y.; Liu, X.; Miao, S.; Liu, J.; Zhang, T. Co–N–C Catalyst for C–C Coupling Reactions: On the Catalytic Performance and Active Sites. ACS Catal. 2015, 5, 6563-6572. (c) Tang, C.; Surkus, A.-E.; Chen, F.; Pohl, M. M.; Agostini, G.; Schneider, M.; Junge, H.; Beller, M. A Stable Nanocobalt Catalyst with Highly Dispersed CoNx Active Sites for the Selective Dehydrogenation of Formic Acid. Angew. Chem., Int. Ed. 2017, 56, 16616-16620. (d) Yang, C.; Fu, L.; Zhu, R.; Liu, Z. Influence of Cobalt Species on the Catalytic Performance of Co-N-C/SiO2 for Ethylbenzene Oxidation. Phys. Chem. Chem. Phys. 2016, 18, 4635-4642. Lu, N.; Zhang, Z.; Ma, N.; Wu, C.; Zhang, G.; Liu, Q.; Liu, T. Copper-Catalyzed Difunctionalization of Allenes with Sulfonyl Iodides Leading to (E)-α-Iodomethyl Vinylsulfones. Org. Lett. 2018, 20, 4318-4322. Bigge, C. F.; Malone, T. C.; Boxer, P. A.; Nelson, C. B.; Ortwine, D. F.; Schelkun, R.; Retz, D. M.; Lescosky, L. J.; Borosky, S. A. Synthesis of 1,4,7,8,9,10-Hexahydro-9-methyl-6-nitropyrido[3,4-f]-quinoxali ne-2,3-dione and Related Quinoxalinediones: Characterization of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (and N-Methyl-D-aspartate) Receptor and Anticonvulsant Activity. J. Med. Chem. 1995, 38, 3720-3740. Troian-Gautier, L.; De Winter, J.; Gerbaux, P.; Moucheron, C. A Direct Method for Oxidizing Quinoxaline, Tetraazaphenanthrene, and Hexaazatriphenylene Moieties Using Hypervalent λ3- Iodinane Compounds. J. Org. Chem. 2013, 78, 11096-11101. (a) Huang, B.; Qi, Q.; Jiang, W.; Tang, J.; Liu, Y.; Fan, W.; Yin, Z.; Shi, F.; Ban, X.; Xu, H.; Sun, Y. Thermally Activated Delayed Fluorescence Materials Based on 3,6-Di-Tert-Butyl-9-((Phenylsulfonyl)Phenyl)-9h-Carbazoles. Dyes Pigments 2014, 111, 135-144; (b) Hartwig, J. F.; Kawatsura, M.; Hauck, S. I.; Shaughnessy, K. H.; Alcazar-Roman, L. M. Room-Temperature Palladium-Catalyzed Amination of Aryl Bromides and Chlorides and Extended Scope of Aromatic C−N Bond Formation with a Commercial Ligand. J. Org. Chem. 1999, 64, 5575-5580.
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