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Asymmetric Formal [5 + 3] Cycloadditions with Unmodified Morita-Baylis-Hillman Alcohols via Double Activation Catalysis Qian-Qian Yang, Xiang Yin, Xiao-Long He, Wei Du, and Ying-Chun Chen ACS Catal., Just Accepted Manuscript • DOI: 10.1021/acscatal.8b04942 • Publication Date (Web): 10 Jan 2019 Downloaded from http://pubs.acs.org on January 11, 2019
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ACS Catalysis
Asymmetric Formal [5 + 3] Cycloadditions with Unmodified MoritaBaylisHillman Alcohols via Double Activation Catalysis Qian-Qian Yang,† Xiang Yin,† Xiao-Long He,† Wei Du,*† and Ying-Chun Chen*†,‡ Key Laboratory of Drug-Targeting and Drug Delivery System of the Ministry of Education and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China ‡ College of Pharmacy, Third Military Medical University, Shapingba, Chongqing 400038, China †
Supporting Information Placeholder ABSTRACT: The discovery of previously unreported activation mode and reaction pathway is important but challenging for the development of asymmetric organocatalysis. Here we disclosed a formal [5 + 3] cycloaddition reaction of unmodified MoritaBaylisHillman alcohols from 2-cyclopentenone and aldehydes with cyclic azomethine imines. A double catalytic system, combining chiral primary amine from cinchona alkaloid and achiral 2-mercaptobenzoic acid, has proved to be crucial for the chemoselectivity and enantioselectivity, through covalently dual activation of the sterically hindered enone substrates. A spectrum of tricyclic frameworks bearing substantial substitutions were produced in moderate to high yields with good stereoselectivity (up to 98% ee, >19:1 dr). Assisted by the experimental observations, a plausible catalytic mechanism is proposed; moreover, the key intermediates suggested have been detected and elucidated by high-resolution mass spectrometry analysis. KEYWORDS: [5 + 3] cycloaddition, unmodified MoritaBaylisHillman alcohol, cyclic azomethine imine, double activation catalysis, asymmetric aminocatalysis, thiol catalysis
The MoritaBaylisHillman (MBH) alcohols are densely functionalized compounds, which have been extensively investigated in the field of asymmetric catalysis.1 On the other hand, much attention has also been paid on the asymmetric transformations with MBH products.2 While fruitful results have been presented under the catalysis of chiral Lewis basic tertiary amines or phosphines,3 the direct application of unmodified MBH alcohols, especially those derived from cyclic enones, has been much less explored. As outlined in Scheme 1a, MBH alcohols were successfully utilized as sterically hindered activated alkenes in rhodium-catalyzed asymmetric -1,4addition/hydroxy elimination reactions, and kinetic resolution of MBH alcohols also could be realized.4 On the other hand, Liu and Chen pioneered the aminocatalytic asymmetric functionalizations of MBH alcohols, and either - or -addition could be accomplished by employing different nucleophiles (Scheme 1b).5 Later, Albrecht and Jørgensen developed ,regioselective [4 + 2] formal cycloadditions of MBH alcohols and 3-olefinic oxindoles, by generating H-bonding dienamine species (Scheme 1c).6 Nevertheless, the development of conceptually new regioselective reaction modes and pathways with unmodified MBH alcohols still remains to be expanded. Cyclic azomethine imines are commonly employed as 1,3dipoles in asymmetric [3 + 2] cycloaddition reactions with diverse activated alkenes.7 They also have been utilized as electrophilic zwitterionic counterparts in [3 + 3] or [4 + 3] formal cycloaddition reactions via metal or organic catalysis.8 In our continuing efforts to develop diverse asymmetric cycloaddition reactions with cyclic enone-type substrates via aminocatalysis,9 we were interested in the potential combination of unmodified MBH alcohols and cyclic
azomethine imines. Here we would like to report the discovery of an unexpected ,-regioselective formal [5 + 3] cycloaddition reaction10 via amine/thiol-based double activation and cascade catalysis, providing an efficient protocol to access the fused tricyclic heterocyclic products with high enantioselectivity (Scheme 1d). Scheme 1. Diverse Regioselective Asymmetric Reactions with Unmodified Cyclic MBH Alcohols a) Rhodium-catalyzed -1,4-additions O OH O O OH Rh(I)/L* R R + * R R1B(OH)2 n * n n n = 1, 2 R1 b) - or -additions via iminium ion catalysis O O * O OH NH2 R or R * R * NuH Nu Nu c) ',-[4 + 2] cyclodditions via dienamine catalysis EtO2C EtO2C O * O OH NH2 + O R [4 + 2] N O N R Boc Boc
d) This work: ',-[5 + 3] cycloadditions via cascade catalysis R1 O * O O OH NH2 ** N N + * N R N thiol R1 [5 + 3] R O
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Table 1. Screening Conditions of Catalytic [5 + 3] Reaction of MBH Alcohol 1a and Azomethine Imine 2aa
+
Ph 1a
N N 2a
Ph
C (20 mol %) A (20 mol %) T (20 mol %)
O
O
HO
solvent, 50 °C Ph 24 h OMe
X
H 3a
O
N
A2
C5
N R C1 X = H, R = H C2 X = OCH3, R = H C3 X = H, R = tBu C4 X = H, R = Ph
*
O O P O OH A3 (R) A4 (S)
O
H
Ph N N H 4a
Ph R
OH N
NH2
O +
NH2
N
H
N N
R3
CO2H
O
2
R1 SH
T1 R1 = CO2H, R2 = R3 = H T2 R1 = R3 = H, R2 = CO2H T3 R1 = R2 = H, R3 = CO2H T4 R1 = CO2Me, R2 = R3 = H T5 R1 = R2 = R3 = H T6 R1 = OH, R2 = R3 = H
entry 1d
cat. C1
acid TFA
thiol /
solvent toluene
yield (%)b 25 (72)
ee (%)c 52 (32)
2d
C1
A2
/
toluene
19:1 dr
Ph
O
O
HO
O Ph 6 96%, 98% ee H
N N 2a
+
Ph
C1 (20 mol %) A2 (20 mol %) T1 (20 mol %)
O
O
a)
T1
R
SH
O
H O
Ph H S
N N NH
2a
Ph
Ph *
H
N N
O III calcd.774.3472 (M+H+) found 774.3488
In order to gain insights into the reaction mechanism, we conducted more experiments. As outlined in Scheme 3a, the
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1,3-dipolar cycloaddition of -benzylidene-2-cyclopentenone 9 and azomethine imine 2a provided the same product 4a but with apparently reduced yield and enantioselectivity under the catalysis of amine C1, acid A2 and thiol T1, in comparison with those with MBH alcohol 1a (59% yield, 44% ee vs 68% yield, 63% ee; data in Table 1, entry 4), indicating that the current formal [5 + 3] cycloaddition would not proceed via the possible 2,2-dienone intermediate 9.17 In addition, apparent deuteration was observed for one -H in product 4a by adding D2O (20 equiv) into the standard catalytic reaction of 1a and 2a, verifying that a protonation process at -position occurs in the reaction (Scheme 3b). As a result, a plausible catalytic cycle is proposed for the formal [5 + 3] cycloaddition of MBH alcohol 1a and azomethine imine 2a via double activation catalysis of amine C1 and thiol T1. As illustrated in Scheme 3c, reversible -addition of thiol T1 to enone 1a would give sulphide I after elimination of H2O.18 Then the more stereoselectively matched dienamine-type intermediate II would be generated between amine C1 and I,12a and -regioselective Mannich-type reaction would proceed with azomethine imine 2a to produce intermediate III accordingly. Since the ortho-carboxylic group of T1 is crucial for the formal [5 + 3] cycloaddition,13b it might serve as an intramolecular H-bonding (or proton) donor to generate the partially cationic sulfonium moiety, which would facilitate the -deprotonation and sequential release of T1 to deliver iminium ion IV.5a Isomerization of IV to 4aminofulvene intermediate V was followed, which could be protonated to giving iminium ion VI.19 Finally, intramolecular aza-Michael addition at -position would construct the observed formal [5 + 3] product 4a after releasing amine C1 via hydrolysis. Notably, the key proposed intermediates I, II, III and V have been successsfully detected by high-resolution mass spectrometry analysis of the catalytic mixture, further supporting the high feasibility of the current covalent double activation catalysis.20 In conclusion, we have investigated an unprecedented ,regioselective formal [5 + 3] cycloaddition reaction of unmodified MoritaBaylisHillman alcohols from 2cyclopentenone with cyclic azomethine imines, which significantly relied on the double activation catalysis of chiral primary amine and achiral 2-mercaptobenzoic acid. The substitution patterns for both types of substrates are substantial, and a spectrum of highly functionalized tricyclic frameworks were effectively produced in moderate to excellent enantioselectivity, which could be further applied to construct chiral architectures with higher molecular complexity. Furthermore, mechanism studies demonstrated that the current formal cycloaddition proceeded in a complicated cascade process via regio- and chemoselective covalently double activation of MoritaBaylisHillman alcohols with amine and thiol catalysts, and the key intermediates have been potentially verified through high-resolution mass spectrometry analysis. Further studies will be reported in due course.
ASSOCIATED CONTENT Supporting Information. The Supporting Information is available free of charge on the ACS Publications website. Complete experimental procedures and characterization of new products; NMR spectra and HPLC chromatograms (PDF); cif files of enantiopure 4c and 6.
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AUTHOR INFORMATION Corresponding Author
[email protected] [email protected] Notes The authors declare no competing financial interests.
Funding Sources We are grateful for the financial support from the NSFC (21572135 and 21772126) and Sichuan University Distinguished Young Scientist Program (2017SCU04A15).
REFERENCES (1) For selected reviews, see: (a) Basavaiah, D.; Rao, A. J.; Satyanarayana, T. Recent Advances in the Baylis−Hillman Reaction and Applications. Chem. Rev. 2003, 103, 811–892. (b) Basavaiah, D.; Rao, A. J.; Reddy, R. J. The Baylis–Hillman Reaction: A Novel Source of Attraction, Opportunities and Challenges in Synthetic Chemistry. Chem. Soc. Rev. 2007, 36, 1581–1588. (c) Masson, G.; Housseman, C.; Zhu, J. The Enantioselective Morita–Baylis–Hillman Reaction and Its Aza Counterpart. Angew. Chem., Int. Ed. 2007, 46, 4614–4628. (d) Wei, Y.; Shi, M. Recent Advances in Organocatalytic Asymmetric Morita–Baylis–Hillman/Aza-Morita–Baylis–Hillman Reactions. Chem. Rev. 2013, 113, 6659–6690. (2) For selected reviews, see: (a) Singh, V.; Batra, S. Advances in the Baylis–Hillman Reaction-Assisted Synthesis of Cyclic Frameworks. Tetrahedron 2008, 64, 4511–4574. (b) Basavaiah, D.; Reddy, B. S.; Badsara, S.S. Recent Contributions from the BaylisHillman Reaction to Organic Chemistry. Chem. Rev. 2010, 110, 5447–5674. (3) For selected reviews, see: (a) Liu, T.-Y.; Xie, M.; Chen, Y.-C. Organocatalytic Asymmetric Transformations of Modified Morita– Baylis–Hillman Adducts. Chem. Soc. Rev. 2012, 41, 4101–4112. (b) Rios, R. Organocatalytic Enantioselective Methodologies Using Morita–Baylis–Hillman Carbonates and Acetates. Catal. Sci. Technol. 2012, 2, 267278. (c) Xie, P.; Huang, Y. Morita–Baylis– Hillman Adduct Derivatives (MBHADs): Versatile Reactivity in Lewis Base-Promoted Annulation. Org. Biomol. Chem. 2015, 13, 85788595. (4) (a) Gendrineau, T.; Genet, J.-P.; Darses, S. Rhodium-Catalyzed Functionalization of Sterically Hindered Alkenes. Org. Lett. 2010, 12, 308310. (b) Wang, F.; Li, S.; Qu, M.; Zhao, M.-X.; Liu, L.-J.; Shi, M. A Highly Efficient Kinetic Resolution of MoritaBaylisHillman Adducts Achieved by N-Ar Axially Chiral Pd-Complexes Catalyzed Asymmetric Allylation. Chem. Commun. 2011, 47, 12813–12815. (c) Wang, Y.; Feng, X.; Du, H. Kinetic Resolution of Hindered MoritaBaylisHillman Adducts by Rh(I)-Catalyzed Asymmetric 1,4-Addition/-Hydroxy Elimination. Org. Lett. 2011, 13, 49544957. (d) Xuan, Q.; Wei, Y.; Chen, J.; Song, Q. An Expedient E-Stereoselective Synthesis of Multi-Substituted Functionalized Allylic Boronates from Morita–Baylis–Hillman Alcohols. Org. Chem. Front. 2017, 4, 1220–1223. (5) (a) Qiao, Z.; Shafiq, Z.; Liu, L.; Yu, Z.-B.; Zheng, Q.-Y.; Wang, D.; Chen, Y.-J. An Organocatalytic, -Regioselective, and Highly Enantioselective Nucleophilic Substitution of Cyclic MoritaBaylisHillman Alcohols with Indoles. Angew. Chem., Int. Ed. 2010, 49, 72947298. (b) Qiao, Z.; Zhong, N.-J.; Zhang, T.; Liu, L.; Wang, D.; Chen, Y.-J. An Organocatalytic, δ-Regioselective, Diastereoselective, and Enantioselective Nucleophilic Substitution of Cyclic Morita–Baylis–Hillman Alcohols with N-Boc-3-benzyl-2oxindoles. Eur. J. Org. Chem. 2013, 2013, 2140–2146. (c) Ren, C.; Wei, F.; Xuan, Q.; Wang, D.; Liu, L. Organocatalytic Enantioselective Reaction of Cyclopent-2-enone-Derived MoritaBaylisHillman Alcohols with 4‐Hydroxycoumarins. Adv. Synth. Catal. 2016, 358,132–137. (6) Stiller, J.; Kowalczyk, D.; Jiang, H.; Jørgensen, K. A.; Albrecht, Ł. Novel Organocatalytic Activation of Unmodified Morita–Baylis–
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ACS Catalysis Hillman Alcohols for the Synthesis of Bicyclic α-Alkylidene Ketones. Chem. - Eur. J. 2014, 20, 13108–13112. (7) For selected examples, see: (a) Chen, W.; Du, W.; Duan, Y.-Z.; Wu, Y.; Yang, S.-Y.; Chen, Y.-C. Enantioselective 1,3-Dipolar Cycloaddition of Cyclic Enones Catalyzed by Multifunctional Primary Amines: Beneficial Effects of Hydrogen Bonding. Angew. Chem., Int. Ed. 2007, 46, 7667−7670. (b) Hong, L.; Kai, M.; Wu, C.; Sun, W.; Zhu, G.; Li, G.; Yao, X.; Wang, R. Enantioselective 1,3Dipolar Cycloaddition of Methyleneindolinones and N,N′-Cyclic Azomethine Imines. Chem. Commun. 2013, 49, 6713−6715. (c) Arai, T.; Ogino, Y.; Sato, T. Development of a Tailor-Made Bis(oxazolidine)pyridineMetal Catalyst for the [3 + 2] Cycloaddition of Azomethine Imines with Propiolates. Chem. Commun. 2013, 49, 77767778. (d) Li, J.; Lian, X.; Liu, X.; Lin, L.; Feng, X. Nickel(II)-Catalyzed Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Imines with Alkylidene Malonates. Chem. - Eur. J. 2013, 19, 51345140. (e) Hori, M.; Sakakura, A.; Ishihara, K. Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Imines with Propioloylpyrazoles Induced by Chiral −Cation Catalysts. J. Am. Chem. Soc. 2014, 136, 13198–13201. (f) Yin, C.; Lin, L.; Zhang, D.; J.; Feng, Liu, X.; Feng, X. Asymmetric [3 + 2] Cycloaddition of Methyleneindolinones with N,N‑Cyclic Azomethine Imines Catalyzed by a N,N‑Dioxide-Mg(OTf)2 Complex. J. Org. Chem. 2015, 80, 9691−9699. (g) Gong, J.; Wan, Q.; Kang, Q. Asymmetric [3 + 2] Cycloaddition Employing N,NCyclic Azomethine Imines Catalyzed by Chiral-at-Metal Rhodium Complex. Org. Lett. 2018, 20, 3354−3357. (8) For selected examples, see: (a) Chan, A.; Scheidt, K. A. Highly Stereoselective Formal [3 + 3] Cycloaddition of Enals and Azomethine Imines Catalyzed by N-Heterocyclic Carbenes. J. Am. Chem. Soc. 2007, 129, 5334−5335. (b) Na, R.; Jing, C.; Xu, Q.; Jiang, H.; Wu, X.; Shi, J.; Zhong, J.; Wang, M.; Benitez, D.; Tkatchouk, E.; Goddard, W. A.; Guo, H.; Kwon, O. Phosphine Catalyzed Annulations of Azomethine Imines: Allene-Dependent [3 + 2], [3 + 3], [4 + 3], and [3 + 2 + 3] Pathways. J. Am. Chem. Soc. 2011, 133, 13337–13348. (c) Jin, Q.; Zhang, J.; Jiang, C.; Zhang, D.; Gao, M.; Hu, S. Self [3 + 4] Cycloadditions of Isatin N,N′-Cyclic Azomethine Imine 1,3-Dipole with N-(o-chloromethyl)aryl Amides. J. Org. Chem. 2018, 83, 8410–8416. (d) (g) Wei, L.; Wang, Z.-F.; Yao, L.; Qiu, G.; Tao, H.; Li, H.; Wang, C.-J.; Copper(II)-Catalyzed Asymmetric 1,3-Dipolar [3 + 4] Cycloaddition and Kinetic Resolution of Azomethine Imines with Azoalkenes. Adv. Synth. Catal. 2016, 358, 39553959. (e) Liang, L.; Huang, Y. PhosphineCatalyzed [3 + 3]-Domino Cycloaddition of Ynones and Azomethine Imines to Construct Functionalized Hydropyridazine Derivatives. Org. Lett. 2016, 18, 2604–2607. (9) (a) Feng, X.; Zhou, Z.; Zhou, R.; Zhou, Q.-Q.; Dong, L.; Chen, Y.C. Stereodivergence in Amine-Catalyzed Regioselective [4 + 2] Cycloadditions of -Substituted Cyclic Enones and Polyconjugated Malononitriles. J. Am. Chem. Soc. 2012, 134, 19942−19947. (b) Feng, X.; Zhou, Z.; Ma, C.; Yin, X.; Li, R.; Dong, L.; Chen, Y.-C. Trienamines Derived from Interrupted Cyclic 2,5-Dienones: Remote δ,ɛ-C=C Bond Activation for Asymmetric Inverse-Electron-Demand Aza-DielsAlder reaction. Angew. Chem., Int. Ed. 2013, 52, 1417314176. (c) Zhou, Z.; Wang, Z.-X.; Ouyang, Q.; Xiao, W.; Du, W.; Chen, Y.-C. Cross-Conjugated Trienamine Catalysis with Alkylidene 2-Cyclohexenones: Application in ,-Regioselective Aza-DielsAlder Reaction. Chem. - Eur. J. 2017, 23, 2945–2949. (d) Zhou, Z.; Wang, Z.-X.; Zhou, Y.-C.; Xiao, W.; Ouyang, Q.; Du, W.; Chen, Y.-C. Switchable Regioselectivity in Amine-Catalysed Asymmetric Cycloadditions. Nat. Chem. 2017, 9, 590−594. (e) Xiao, W.; Yang, Q.-Q.; Chen, Z.; Ouyang, Q.; Du, W.; Chen, Y.-C. Regioand Diastereodivergent [4 + 2] Cycloadditions with Cyclic 2,4Dienones. Org. Lett. 2018, 20, 236239. (10) For limited examples, see: (a) Yin, X.; Zheng, Y.; Feng, X.; Jiang, K.; Wei, X.-Z.; Gao, N.; Chen, Y.-C. Asymmetric [5 + 3] Formal Cycloadditions with Cyclic Enones through Cascade Dienamine– Dienamine Catalysis. Angew. Chem., Int. Ed. 2014, 53, 6245–6248.
(b) Yuan, C.; Wu, Y.; Wang, D.; Zhang, Z.; Wang, C.; Zhou, L.; Zhang, C.; Song, B.; Guo, H. Formal [5 + 3] Cycloaddition of Zwitterionic Allylpalladium Intermediates with Azomethine Imines for Construction of N,O-Containing Eight-Membered Heterocycles. Adv. Synth. Catal. 2018, 360, 652658. (c) Krishna, U. M.; Deodhar, K. D.; Trivedi, G. K.; Mobin, S. M. Novel Route to Functionalized Cyclooctanoids via [5 + 3] Cycloaddition. J. Org. Chem. 2004, 69, 967969. (d) Arrayás, R. G.; Liebeskind, L. S. 3-Pyranyl and 3Pyridinyl Molybdenum -Complexes as Chiral Scaffolds for the Enantioselective Construction of Substituted Oxa- and Aza[3.3.1]bicyclics: First Enantio- and Regiocontrolled [5 + 3] Cycloaddition Reactions. J. Am. Chem. Soc. 2003, 125, 90269027. (11) For more details, see the Supporting Information. (12) (a) Wang, Z.-X.; Zhou, Z.; Xiao, W.; Ouyang, Q.; Du, W.; Chen, Y.-C. Double Activation Catalysis for α-Alkylidene Cyclic Enones with Chiral Amines and Thiols. Chem. - Eur. J. 2017, 23, 10678– 10682. (b) Yang, Q.-Q.; Xiao, W.; Du, W.; Ouyang, Q.; Chen, Y.-C. Asymmetric [4 + 2] Annulations to Construct Norcamphor Scaffolds with 2-Cyclopentenone via Double Amine-Thiol Catalysis. Chem. Commun. 2018, 54, 11291132. For reviews, see: (c) Skubi, K. L.; Blum, T. R.; Yoon, T. P. Dual Catalysis Strategies in Photochemical Synthesis. Chem. Rev. 2016, 116, 10035–10074. (d) Afewerki, S.; Córdova, A. Combinations of Aminocatalysts and Metal Catalysts: A Powerful Cooperative Approach in Selective Organic Synthesis. Chem. Rev. 2016, 116, 13512–1357. (13) For selected examples of thiol-mediated or catalyzed reactions, see: (a) Aroyan, C. E.; Miller, S. J. Enantioselective Rauhut−Currier Reactions Promoted by Protected Cysteine. J. Am. Chem. Soc. 2007, 129, 256–257. (b) The ortho-acidic group has been proved to be crucial for the thiol catalysis, see: Selig, P. S.; Miller, S. J. OrthoAcidic Aromatic Thiols as Efficient Catalysts of Intramolecular Morita–Baylis–Hillman and Rauhut–Currier Reactions. Tetrahedron Lett. 2011, 52, 2148–2151. (c) Hashimoto, T.; Kawamata, Y.; Maruoka, K. An Organic Thiyl Radical Catalyst for Enantioselective Cyclization. Nat. Chem. 2014, 6, 702–705. (14) C,N-Cyclic azomethine imines failed to participate in similar formal [5 + 3] cycloadditions. For selected examples, see: (a) Cheng, X.; Cao, X.; Xuan, J.; Xiao, W.-J. Silver(I)- and BaseMediated [3 + 3]-Cycloaddition of C,N-Cyclic Azomethine Imines with Aza-Oxyallyl Cations. Org. Lett. 2018, 20, 52–55. (b) Zhu, C.Z.; Feng, J.-J.; Zhang, J. Rhodium-Catalyzed Intermolecular [3 + 3] Cycloaddition of Vinyl Aziridines with C,N-Cyclic Azomethine Imines: Stereospecific Synthesis of Chiral Fused Tricyclic 1,2,4Hexahydrotriazines. Chem. Commun. 2017, 53, 46884691. (c) Yuan, C.; Zhou, L.; Xia, M.; Sun, Z.; Wang, D.; Guo, H. PhosphineCatalyzed Enantioselective [4 + 3] Annulation of Allenoates with C,N-Cyclic Azomethine Imines: Synthesis of Quinazoline-Based Tricyclic Heterocycles. Org. Lett. 2016, 18, 5644−5647. (d) Zhang, L.; Liu, H.; Qiao, G.; Hou, Z.; Liu, Y.; Xiao, Y.; Guo, H. PhosphineCatalyzed Highly Enantioselective [3 + 3] Cycloaddition of Morita−Baylis−Hillman Carbonates with C,N-Cyclic Azomethine Imines. J. Am. Chem. Soc. 2015, 137, 4316–4319. (e) Wang, D.; Lei, Y.; Wei, Y.; Shi, M. A Phosphine-Catalyzed Novel Asymmetric [3 + 2] Cycloaddition of C,N-Cyclic Azomethine Imines with Substituted Allenoates. Chem. - Eur. J. 2014, 20, 1532515329. (15) (a) Lee, K. J.; Choi, J.-K.; Yum, E. K.; Cho, S. Y. Novel 1,3Dipolar Cycloadditions of Fulvenes and Hydrazonyl Chlorides: A Facile Synthesis of the Cyclopenta[d]pyridazines. Tetrahedron Lett. 2009, 50, 6698–6700. (b) Moeinpour, F.; Bakavoli, M.; Davoodnia, A.; Morsali, A. Investigation into the Regiochemistry of Some Pyrazoles Derived from 1,3-Dipolar Cycloaddition of Acrylonitrile with Some Nitrilimines: Theoretical and Experimental Studies. J. Chil. Chem. Soc. 2011, 56, 870874. (16) Yamashita, Y.; Kobayashi, S. NO Cations as Highly Efficient Catalysts for Carbon–Carbon Bond Forming Reactions. Chem. Lett. 2009, 38, 678–679. (17) In comparison with the data (52% ee) in Table 1, entry 1, apparently different enantioselectivity for cycloadduct 4a (33% ee)
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was observed for the reaction of 2,2-dienone 9 and 2a under the same catalysis of amine C1 and TFA, also suggesting that different reaction pathways would be involved. See the Supporting Information for more details. (18) The in situ 1H NMR analysis supported the formation of intermediate I. See the Supporting Information for more details. (19) MBH alcohols derived from 2-cyclohexenone failed to participate in such a reaction, which cannot undergo similar isomerization processes. (20) Mass spectrometry analysis has been widely applied for mechanism studies, see: (a) Di Marco, V. B.; Bombi, G. G. Electrospray Mass Spectrometry (ESI-MS) in the Study of MetalLigand Solution Equilibria. Mass Spectrom. Rev. 2006, 25, 347379. (b) Vikse, K. L.; Ahmadi, Z.; McIndoe, J. S. The Application of Electrospray Ionization Mass Spectrometry to Homogeneous Catalysis. Coord. Chem. Rev. 2014, 279, 96114. (c) Wang, H.; Zhang, L.; Tu, Y.; Xiang, R.; Guo, Y.-L.; Zhang, J. Phosphine-
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Catalyzed Difunctionalization of -Fluoroalkyl ,-Enones: A Direct Approach to -Amino -Diazo Carbonyl Compounds. Angew. Chem., Int. Ed. 2018, 57, 1578715791. (d) Jiang, G.; List, B. Direct Asymmetric -Allylation of Aldehydes with Simple Allylic Alcohols Enabled by the Concerted Action of Three Different Catalysts. Angew. Chem., Int. Ed. 2011, 55, 94719474. (e) Tao, Z.-L.; Zhang, W.-Q.; Chen, D.-F.; Adele, A.; Gong, L.-Z. Pd-Catalyzed Asymmetric Allylic Alkylation of Pyrazol-5-ones with Allylic Alcohols: The Role of the Chiral Phosphoric Acid in C−O Bond Cleavage and Stereocontrol. J. Am. Chem. Soc. 2013, 135, 9255−9258. (g) Zheng, P.-F.; Ouyang, Q.; Niu, S.-L.; Shuai, L.; Yuan, Y.; Jiang, K.; Liu, T.-Y.; Chen, Y.-C. Enantioselective [4 + 1] Annulation Reactions of ‑Substituted Ammonium Ylides to Construct Spirocyclic Oxindoles. J. Am. Chem. Soc. 2015, 137, 9390−9399.
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ACS Catalysis SYNOPSIS TOC
HO R
O
O +
N N
amine (20 mol %) acid (20 mol %)
O
H
R1 N N
thiol (20 mol %) R1
amine/thiol double activation catalysis formal [5 + 3] cycloadditions
R
H
O >19:1 dr 8198% ee
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