Subscribe to RSS
Please copy the URL and add it into your RSS Feed Reader.
https://www.thieme-connect.de/rss/thieme/en/10.1055-s-00000083.xml
Synlett 2016; 27(07): 1006-1021
DOI: 10.1055/s-0035-1561322
DOI: 10.1055/s-0035-1561322
account
Aminocatalytic Enantioselective Cycloadditions
Further Information
Publication History
Received: 16 November 2015
Accepted after revision: 12 December 2015
Publication Date:
11 February 2016 (online)
Abstract
Aminocatalysis applied to cycloaddition chemistry has gained an outstanding level of efficiency and sophistication, with many examples in which the different organocatalytic activation manifolds have been applied to develop catalytic and enantioselective variants of synthetically relevant cycloaddition reactions. In this account, a selection of relevant contributions to this field carried out in our laboratories will be presented, showing that the catalytic generation of either electron-poor α,β-unsaturated iminium ions or, alternatively, electron-rich dienamines or trienamines can constitute a very useful approach for the activation of (poly)unsaturated aldehydes toward different types of reagents. Importantly, this account also shows that reactions can be designed from the beginning leading to the expected products and that proceed with excellent performance once an appropriate catalyst and conditions are selected. Alternatively, it is also shown that, in some cases, unexpected results are obtained which have led us to the discovery of interesting transformations that are unprecedented in the chemical literature.
1 Introduction
2 Formal [3+2] Cycloaddition with Azomethine Ylides
3 Attempted [3+2] Cycloaddition Using Hydrazones as Azomethine Imine Precursors
4 [5+2] Cycloaddition Between Oxidopyrylium Ylides and Enals under Dienamine Activation
5 [2+2] Cycloaddition Between Nitroalkenes and Enals under Dienamine Activation
6 Trienamine Activation. Unconjugated Dienals as Active Substrates in [4+2] Cycloaddition
7 Summary and Outlook
-
References
- 1a Kobayashi S, Jørgensen KA. Cycloaddition Reactions in Organic Synthesis . Wiley-VCH; Weinheim: 2002
- 1b Wipf P, Fang Z, Ferrie L, Ueda M, Walczak MA. A, Yan Y, Yang M. Pure Appl. Chem. 2013; 85: 1079
- 1c Ylijoki KE. O, Stryker JM. Chem. Rev. 2013; 113: 2244
- 1d Pellissier H. Tetrahedron 2012; 68: 2197
- 1e Moyano A, Rios R. Chem. Rev. 2011; 111: 4703
- 2a Ager DJ, de Vries AH. M, de Vries JG. Chem. Soc. Rev. 2012; 41: 3340
- 2b Howell GP. Org. Proc. Res. Dev. 2012; 16: 1258
- 2c Busacca CA, Fandrick DR, Song JJ, Senanayake CH. Adv. Synth. Catal. 2011; 353: 1825
- 2d Blaser H.-U, Federsel H.-J. Asymmetric Catalysis on Industrial Scale . Wiley-VCH; Weinheim: 2010. 2nd ed.
- 2e Farina V, Reeves JT, Senanayake CH, Song JJ. Chem. Rev. 2006; 106: 2734
- 3a Science of Synthesis, Asymmetric Organocatalysis . List B, Maruoka K. Georg Thieme Verlag; Stuttgart: 2012
- 3b Comprehensive Enantioselective Organocatalysis. Dalko PI. Wiley-VCH; Weinheim: 2013
- 3c Scheffler U, Mahrwald R. Chem. Eur. J. 2013; 19: 14346
- 3d Jacobsen EN, MacMillan DW. C. Proc. Nat. Acad. Sci. U.S.A. 2010; 107: 20618
- 3e Bertelsen S, Jørgensen KA. Chem. Soc. Rev. 2009; 38: 2178
- 3f MacMillan DW. C. Nature 2008; 455: 304
- 3g Dondoni A, Massi M. Angew. Chem. Int. Ed. 2008; 47: 4638
- 3h List B, Yang J.-W. Science 2006; 313: 1584
- 3i Movassaghi M, Jacobsen EN. Science 2002; 298: 1904
- 4a Paz BM, Jiang H, Jørgensen KA. Chem. Eur. J. 2015; 21: 1846
- 4b Holland MC, Gilmour R. Angew. Chem. Int. Ed. 2015; 54: 3862
- 4c Melchiorre P. Angew. Chem. Int. Ed. 2012; 51: 9748
- 4d Melchiorre P, Marigo M, Carlone A, Bartoli G. Angew. Chem. Int. Ed. 2008; 47: 6138
- 4e List B. Chem. Commun. 2006; 819
- 5a Jurberg ID, Chatterjee I, Tannert R, Melchiorre P. Chem. Commun. 2013; 49: 4869
- 5b Jiang H, Albrecht L, Jørgensen KA. Chem. Sci. 2013; 4: 2287
- 5c Arceo E, Melchiorre P. Angew. Chem. Int. Ed. 2012; 51: 5290
- 5d Ramachary DB, Reddy YV. Eur. J. Org. Chem. 2012; 865
- 6 Duan J, Li P. Catal. Sci. Technol. 2014; 4: 311 ; see also refs. 5a–c
- 7 Ahrendt KA, Borths CJ, MacMillan DW. C. J. Am. Chem. Soc. 2000; 122: 4243
- 8 Jen WS, Wiener JJ. M, MacMillan DW. C. J. Am. Chem. Soc. 2000; 121: 9874
- 9a Adrio J, Carretero JC. Chem. Commun. 2014; 50: 12434
- 9b Adrio J, Carretero JC. Chem. Commun. 2011; 47: 6784
- 9c Garner P, Kaniskan HU. Curr. Org. Synth. 2010; 7: 348
- 9d Pandey G, Banerjee P, Gadre SR. Chem. Rev. 2006; 106: 4484
- 9e Bonin M, Chauveau A, Micouin L. Synlett 2006; 2349
- 9f Najera C, Sansano JM. Angew. Chem. Int. Ed. 2005; 44: 6272
- 9g Husinec S, Savic V. Tetrahedron: Asymmetry 2005; 16: 2047
- 9h Coldham I, Hufton R. Chem. Rev. 2005; 105: 2765
- 10 Grigg R. Chem. Soc. Rev. 1987; 16: 89
- 11 Grigg R, Donegan G, Gunaratne HQ. N, Kennedy DA, Malone JF, Sridharan V, Thianpatanagul S. Tetrahedron 1989; 45: 1723
- 12 Vicario JL, Reboredo S, Badía D, Carrillo L. Angew. Chem. Int. Ed. 2007; 46: 5168
- 13 In fact, further experiments in our laboratories have shown that the hemiaminal synthesized by condensation between cycloadduct 3a and catalyst 4a required a long reaction time or reflux temperature for the hydrolysis with water in THF.
- 14a Donslund BS, Johansen TK, Poulsen PH, Halskov KS, Jørgensen KA. Angew. Chem. Int. Ed. 2015; 54: 13860
- 14b Meninno S, Lattanzi A. Chem. Commun. 2013; 49: 3821
- 14c Jensen KL, Dickmeiss G, Jiang H, Albrecht L, Jørgensen KA. Acc. Chem. Res. 2012; 45: 248
- 14d Palomo C, Mielgo A. Angew. Chem. Int. Ed. 2006; 45: 7876
- 14e Mielgo A, Palomo C. Chem. Asian J. 2008; 3: 922
- 15 Ibrahem I, Rios R, Vesely J, Córdova A. Tetrahedron Lett. 2007; 48: 6252
- 16 Lin S, Deiana L, Zhao G.-L, Sun J, Cordova A. Angew. Chem. Int. Ed. 2011; 50: 7624
- 17a Wang L, Shi X.-M, Dong W.-P, Zhu L.-P, Wang R. Chem. Commun. 2013; 49: 3458
- 17b Shi F, Zhu R.-Y, Liang X, Tu S.-J. Adv. Synth. Catal. 2013; 355: 2447
- 17c Bai J.-F, Wang L.-L, Peng L, Guo Y.-L, Ming J.-N, Wang F.-Y, Xu X.-Y, Wang L.-X. Eur. J. Org. Chem. 2011; 4472
- 17d Yu J, Shi F, Gong L.-Z. Acc. Chem. Res. 2011; 44: 1156
- 17e Xue M.-X, Zhang X.-M, Gong L.-Z. Synlett 2008; 691
- 17f Liu Y.-K, Liu H, Du W, Yue L, Chen Y.-C. Chem. Eur. J. 2008; 14: 9873
- 17g Chen X.-H, Zhang W.-Q, Gong L.-Z. J. Am. Chem. Soc. 2008; 130: 5652
- 17h Xie J, Yoshida K, Takasu K, Takemoto Y. Tetrahedron Lett. 2008; 49: 6910
- 18a Iza A, Carrillo L, Vicario JL, Badia D, Reyes E. Org. Biomol. Chem. 2010; 8: 2238
- 18b Iza A, Ugarriza I, Uria U, Reyes E, Carrillo L, Vicario JL. Tetrahedron 2013; 69: 8878
- 19 Reboredo S., Uria U., Reyes E., Carrillo L., Vicario J. L. manuscript in preparation.
- 20 Ugarriza U, Uria U, Carrilo L, Vicario JL, Reyes E. Chem. Eur. J. 2014; 20: 11650
- 21 Reboredo S, Reyes E, Vicario JL, Badia D, Carrillo L, de Cozar A, Cossío FP. Chem. Eur. J. 2012; 18: 7179
- 22 Reboredo S, Vicario JL, Carrillo L, Reyes E, Uria U. Synthesis 2013; 45: 2669
- 23 Mase N, Barbas CF. III. Org. Biomol. Chem. 2010; 8: 4043
- 24 Reboredo S, Vicario JL, Badía D, Carrillo L, Reyes E. Adv. Synth. Catal. 2011; 353: 3307
- 25a Fernandez N, Carrillo L, Vicario JL, Badia D, Reyes E. Chem. Commun. 2011; 47: 12313
- 25b See also: Fraile A, Schietroma DM. S, Albrecht A, Davis RL, Jørgensen KA. Chem. Eur. J. 2012; 18: 2773
- 26 For a review on [3+2] cycloadditions using azomethine imines, see: Nájera C, Sansano JM, Yus M. Org. Biomol. Chem. 2015; 13: 8596
- 27a Izquierdo C, Esteban F, Parra A, Alfaro R, Aleman J, Fraile A, García-Ruano JL. J. Org. Chem. 2014; 79: 10417
- 27b Suga H, Arikawa T, Itoh K, Okumura Y, Kakehi A, Shiro M. Heterocycles 2010; 81: 1669
- 27c Chen W, Du W, Duan Y.-Z, Wu Y, Yang S.-Y, Chen Y.-C. Angew. Chem. Int. Ed. 2007; 46: 7667
- 27d Chen W, Yuan X.-H, Li R, Du W, Wu Y, Ding L.-S, Chen Y.-C. Adv. Synth. Catal. 2006; 348: 1818
- 27e Hesping L, Biswas A, Daniluc CG, Mück-Lichtenfeld C, Studer A. Chem. Sci. 2015; 6: 1252
- 27f Hong X, Küçuk HB, Maji MS, Yang Y.-F, Rueping M, Houk KN. J. Am. Chem. Soc. 2014; 136: 13769
- 27g Rueping M, Maji MS, Küçük HB, Atodiresei I. Angew. Chem. Int. Ed. 2012; 51: 12864
- 27h Hashimoto T, Omote M, Maruoka K. Angew. Chem. Int. Ed. 2011; 50: 3489
- 28a Brehme R, Enders D, Fernandez R, Lassaletta JM. Eur. J. Org. Chem. 2007; 5629
- 28b Serrano I, Monge D, Álvarez E, Fernández R, Lassaletta JM. Chem. Commun. 2015; 51: 4077
- 28c Monge D, Crespo-Peña AM, Martín-Zamora E, Alvarez E, Fernández R, Lassaletta JM. Chem. Eur. J. 2013; 19: 8421
- 28d Crespo-Peña A, Monge D, Martín-Zamora E, Alvarez E, Fernández R, Lassaletta JM. J. Am. Chem. Soc. 2012; 134: 12912
- 28e Hashimoto T, Hirose M, Maruoka K. J. Am. Chem. Soc. 2008; 130: 7556
- 28f Herrera RP, Monge D, Martín-Zamora E, Fernández R, Lassaletta JM. Org. Lett. 2007; 9: 3303
- 28g Rueping M, Sugiono E, Theissmann T, Kuenkel A, Kockritz A, Pews-Davtyan A, Nemati N, Beller M. Org. Lett. 2007; 9: 1065
- 28h Dixon DJ, Tillman AL. Synlett 2005; 2635
- 29a Johnson JS. Angew. Chem. Int. Ed. 2004; 43: 1326
- 29b Enders D, Shilvock JP. Chem. Soc. Rev. 2000; 29: 359
- 29c For a formal conjugate addition of an hydroxymoyl anion equivalent to enals under iminium catalysis developed in our group, see: Alonso B, Reyes E, Carrillo L, Vicario JL, Badia D. Chem. Eur. J. 2011; 17: 6048
- 30 Fernández M, Uria U, Vicario JL, Reyes E, Carrillo L. J. Am. Chem. Soc. 2012; 134: 11872
- 31 Barton DH. R, Jaszberenyi JC, Liu W, Shinada T. Tetrahedron 1996; 52: 14673
- 32 For an excellent overview, see: Nielsen M, Worgull D, Zweifel T, Gschwend B, Bertelsen S, Jørgensen KA. Chem. Commun. 2011; 47: 632 ; see also ref. 5c
- 33a Ylijoki KE. O, Stryker JM. Chem. Rev. 2013; 113: 2244
- 33b Pellisier H. Adv. Synth. Catal. 2011; 353: 189
- 33c Mascareñas JL. Adv. Cycloaddition 1999; 6: 1
- 33d Singh V, Krishna UM, Vikrant GK. T. Tetrahedron 2008; 64: 3405
- 33e Wender PA, Love JA. Adv. Cycloaddition 1999; 5: 1
- 34a Hendrickson JB, Farina JS. J. Org. Chem. 1980; 45: 3359
- 34b Yadav AA, Sarang PS, Sau M, Thirumalairajan S, Trivedi GK, Salunkhe MM. Tetrahedron Lett. 2012; 53: 3599
- 34c Snider BB, Wu X, Nakamura S, Hashimoto S. Org. Lett. 2007; 9: 873
- 34d Celanire S, Marlin F, Baldwin JE, Adlington RM. Tetrahedron 2005; 61: 3025
- 34e Delgado AD, Castedo L, Mascareñas JL. Org. Lett. 2002; 4: 3091
- 34f Ohmori N. Chem. Commun. 2001; 1552
- 34g Sammes PG, Street LJ. J. Chem. Soc., Perkin Trans. 1 1983; 1261
- 34h Sammes PG, Street LJ, Kirby P. J. Chem. Soc., Perkin Trans. 1 1983; 2729
- 34i Sammes PG, Street LJ. J. Chem. Soc., Chem. Commun. 1982; 1056
- 35a Tchabanenko K, Sloan C, Bunetel Y.-M, Mullen P. Org. Biomol. Chem. 2014; 10: 4215
- 35b Nicolaou KC, Kang Q, Ng SY, Chen DY.-K. J. Am. Chem. Soc. 2010; 132: 8219
- 35c Tang B, Bray CD, Pattenden G. Org. Biomol. Chem. 2009; 7: 4448
- 35d Wang SC, Tantillo DJ. J. Org. Chem. 2008; 73: 1516
- 35e Wender PA, Bi FC, Buschmann N, Gosselin F, Kan C, Kee J.-M, Ohmura H. Org. Lett. 2006; 8: 5373
- 35f Roethle PA, Hernandez PT, Trauner D. Org. Lett. 2006; 8: 5901
- 35g Tang B, Bray CD, Pattenden G. Tetrahedron Lett. 2006; 47: 6401
- 35h Aggarwal VK, Grainger RS, Newton GK, Spargo PL, Hobson AD, Adams H. Org. Biomol. Chem. 2003; 1: 1884
- 35i Lopez F, Castedo L, Mascareñas JL. Org. Lett. 2002; 4: 3683
- 35j Wender PA, Jesudason CD, Nakahira H, Tamura N, Tebbe AL, Ueno Y. J. Am. Chem. Soc. 1997; 119: 12976
- 35k Bauta WE, Booth J, Bos ME, DeLuca M, Diorazio L, Donohoe TJ, Frost C, Magnus N, Magnus P, Mendoza J, Pye P, Tarrant JG, Thom S, Ujjainwalla F. Tetrahedron 1996; 52: 14081
- 35l Wender PA, Lee HY, Wilhelm RS, Williams PD. J. Am. Chem. Soc. 1989; 111: 8954
- 36a For an intramolecular version, see: Burns NZ, Witten MR, Jacobsen EN. J. Am. Chem. Soc. 2011; 133: 14578
- 36b For a subsequent intermolecular version, see: Witten MR, Jacobsen EN. Angew. Chem. Int. Ed. 2014; 53: 5912
- 36c For a previous attempt on an enantioselective [5+2] oxidopyrylium cycloaddition proceeding with poor enantiocontrol, see: Hodgson DM, Stupple PA, Johnstone C. ARKIVOC 2003; (vii): 49
- 37 Orue A, Reyes E, Vicario JL, Carrillo L, Uria U. Org. Lett. 2012; 14: 3740
- 38a Bertelsen S, Marigo M, Brandes S, Diner P, Jørgensen KA. J. Am. Chem. Soc. 2006; 128: 12973
- 38b Mose R, Jensen ME, Preegel G, Jørgensen KA. Angew. Chem. Int. Ed. 2015; 54: 13630
- 38c Martin-Santos C, Jarava-Barrera C, del Pozo S, Parra A, Diaz-Tendero S, Mas-Balleste R, Cabrera S, Aleman J. Angew. Chem. Int. Ed. 2014; 53: 8184
- 38d Gu J, Ma C, Li Q.-Z, Du W, Chen Y.-C. Org. Lett. 2014; 16: 3986
- 38e Feng X, Zhou Z, Zhou R, Zhou Q.-Q, Dong L, Chen Y.-C. J. Am. Chem. Soc. 2012; 134: 19942
- 38f Wang Z.-Y, Wong W.-T, Yang D. Org. Lett. 2013; 15: 4980
- 38g Xu D.-Q, Xia A.-B, Luo S.-P, Tang J, Zhang S, Jiang J.-R, Xu Z.-Y. Angew. Chem. Int. Ed. 2009; 48: 3821
- 38h Bencivenni G, Wu L.-Y, Mazzanti A, Giannichi B, Pesciaioli F, Song M.-P, Bartoli G, Melchiorre P. Angew. Chem. Int. Ed. 2009; 48: 7200
- 38i Wu L.-Y, Bencivenni G, Mancinelli M, Mazzanti A, Bartoli G, Melchiorre P. Angew. Chem. Int. Ed. 2009; 48: 7196
- 38j de Figueiredo RM, Fröhlich R, Christmann M. Angew. Chem. Int. Ed. 2008; 47: 1450
- 38k Sundén H, Rios R, Xu Y, Eriksson L, Córdova A. Adv. Synth. Catal. 2007; 349: 2549
- 38l Momiyama N, Yamamoto Y, Yamamoto H. J. Am. Chem. Soc. 2007; 129: 1190
- 38m Hong B.-C, Wu M.-F, Tseng H.-C, Huang G.-F, Su C.-F, Liao J.-H. J. Org. Chem. 2007; 72: 8459
- 38n Bench BJ, Liu C, Evett CR, Watanabe CM. H. J. Org. Chem. 2006; 71: 9458
- 38o Ramachary DB, Anebouselvy K, Chowdari NS, Barbas CF. III. J. Org. Chem. 2004; 69: 5838 ; and references therein
- 38p Thayumanavan R, Ramachary DB, Sakthivel K, Tanaka F, Barbas CF. III. Tetrahedron Lett. 2002; 43: 3817
- 39 Orue A, Uria U, Reyes E, Carrillo L, Vicario JL. Angew. Chem. Int. Ed. 2015; 54: 3043
- 40a Albrecht L, Dickmeiss G, Acosta FC, Rodríguez-Escrich C, Davis RL, Jørgensen KA. J. Am. Chem. Soc. 2012; 134: 2543
- 40b Weise CF, Lauridsen VH, Rambo RS, Iversen EH, Olsen M.-L, Jørgensen KA. J. Org. Chem. 2014; 79: 3537
- 40c Albrecht L, Gómez CV, Jacobsen CB, Jørgensen KA. Org. Lett. 2013; 15: 3010
- 40d Jiang H, Rodriguez-Escrich C, Johansen TK, Davis RL, Jørgensen KA. Angew. Chem. Int. Ed. 2012; 51: 10271
- 40e Albrecht L, Acosta FC, Fraile A, Albrecht A, Christensen J, Jørgensen KA. Angew. Chem. Int. Ed. 2012; 51: 9088
- 40f Albrecht L, Dickmeiss G, Weise CF, Rodriguez-Escrich C, Jørgensen KA. Angew. Chem. Int. Ed. 2012; 51: 13109
- 41 Roca-López D, Uria U, Reyes E, Carrillo L, Jørgensen KA, Vicario JL, Merino P. Chem. Eur. J. 2016; 22: 884
- 42 Talavera G, Reyes E, Vicario JL, Carrillo L. Angew. Chem. Int. Ed. 2012; 51: 4104
- 43a Patora-Komisarska K, Benohoud M, Ishikawa H, Seebach D, Hayashi Y. Helv. Chim. Acta 2011; 94: 719
- 43b Burés J, Armstrong A, Blackmond DG. J. Am. Chem. Soc. 2011; 133: 8822
- 44a Talavera G, Reyes E, Vicario JL, Carrillo L, Uria U. Adv. Synth. Catal. 2013; 355: 653
- 44b Fernandez M, Reyes E, Vicario JL, Badía D, Carrillo L. Adv. Synth. Catal. 2012; 354: 371
- 44c Reyes E, Talavera G, Vicario JL, Badia D, Carrillo L. Angew. Chem. Int. Ed. 2009; 48: 5701
- 45a Jia Z.-J, Jiang H, Li J.-L, Gschwend B, Li Q.-Z, Yin X, Grouleff J, Chen Y.-C, Jørgensen KA. J. Am. Chem. Soc. 2011; 133: 5053
- 45b For a review on trienamine catalysis, see: Kumar I, Ramaraju P, Mir NA. Org. Biomol. Chem. 2013; 11: 709 ; see also ref. 5c
- 46 Prieto L, Talavera G, Uria U, Reyes E, Vicario JL, Carrillo L. Chem. Eur. J. 2014; 20: 2145
- 47a Pantaine L, Coeffard V, Moreau X, Greck C. Eur. J. Org. Chem. 2015; 2005
- 47b Li Y, Lopez-Delgado FJ, Jørgensen DK. B, Nielsen RP, Jiang H, Jørgensen KA. Chem. Commun. 2014; 50: 15689
- 47c Blanco V, Leigh DA, Lewandowska U, Lewandowski B, Marcos V. J. Am. Chem. Soc. 2014; 136: 15775
- 47d Coelho JA. S, Trindade AF, Andre V, Teresa-Duarte M, Veiros LF, Afonso CA. M. Org. Biomol. Chem. 2014; 12: 9324
- 47e Cruz-Cruz D, Mose R, Villegas-Gomez C, Torbensen SV, Larsen MS, Jørgensen KA. Chem. Eur. J. 2014; 20: 11331
- 47f Xiao Y.-C, Yue C.-Z, Chen P.-Q, Chen Y.-C. Org. Lett. 2014; 16: 3208
- 47g Li X, Lin M.-H, Han Y, Wang F, Cheng J.-P. Org. Lett. 2014; 16: 114
- 47h Ma C, Jia Z.-J, Liu J.-X, Zhou Q.-Q, Dong L, Chen Y.-C. Angew. Chem. Int. Ed. 2013; 52: 948
- 47i Zhang S.-J, Zhang J, Zhou Q.-Q, Dong L, Chen Y.-C. Org. Lett. 2013; 15: 968
- 47j Rodríguez-Escrich C, Davis RL, Jiang H, Stiller J, Johansen TK, Jørgensen KA. Chem. Eur. J. 2013; 19: 2932
- 47k Jiang H, Cruz D, Li Y, Lauridsen VH, Jørgensen KA. J. Am. Chem. Soc. 2013; 135: 5200
- 47l Liu Y, Nappi M, Escudero-Adan EC, Melchiorre P. Org. Lett. 2012; 14: 1310
- 47m Jia Z.-J, Zhou Q, Zhou Q.-Q, Chen P.-Q, Chen Y.-C. Angew. Chem. Int. Ed. 2011; 50: 8638
- 47n Jiang H, Gschwend B, Albrecht L, Hansen SG, Jørgensen KA. Chem. Eur. J. 2011; 17: 9032
- 47o Liu Y.-K, Nappi M, Arceo E, Vera S, Melchiorre P. J. Am. Chem. Soc. 2011; 133: 15212 ; see also ref. 40d
For some selected reviews, see:
For two recent reference works, see:
For some selected general reviews on organocatalysis, see:
For some selected reviews specifically focused on aminocatalysis, see:
For some reviews on the utility of diarylprolinol-based organocatalysts, see:
For examples of [3+2] cycloadditions using stable azomethine imines under the iminium activation approach, see:
For additional examples using other organocatalytic activation manifolds, see:
For a review on the use of hydrazones as C-nucleophiles, see:
For some examples regarding their use under organocatalytic activation, see:
For reviews, see:
For reviews, see:
For a pioneering report, see:
For some examples, see:
For a pioneering report on the participation of catalytically generated dienamines as dienes in Diels–Alder reactions, see:
For other examples, see
See also:
We have observed this positive effect associated with a final hemiacetal/hemiaminal stabilization event as the final reaction of a cascade process involving iminium/enamine activation in other cases. See for example:
For a pioneering report, see: