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DOI: 10.1055/s-0031-1289788
NHCs in Asymmetric Organocatalysis: Recent Advances in Azolium Enolate Generation and Reactivity
Publication History
Received: 17 April 2012
Accepted after revision: 03 May 2012
Publication Date:
13 July 2012 (online)

Abstract
Organocatalysis represents a synthetic paradigm that has grown exponentially in popularity over the last decade, arguably becoming one of the most desired synthetic methods for the creation of enantiomerically enriched products. Within this field the use of N-heterocyclic carbenes (NHCs) has seen appreciable research activity with the realisation of many novel reaction types. This review provides a comprehensive account of recent advances in the generation and reactivity of azolium enolates with exclusive focus on those processes rendered asymmetric through the use of chiral NHCs.
1 Introduction: NHCs in Organocatalysis
1.1 Azolium Enolates
2 Azolium Enolate Generation via Ketenes
2.1 Asymmetric Formal [2+2] Cycloadditions
2.2 Asymmetric Formal [3+2] Cycloadditions
2.3 Asymmetric Formal [4+2] Cycloadditions
2.4 Asymmetric Protonation and Halogenation
3 Azolium Enolate Generation via α-Functionalised Aldehydes
4 Azolium Enolate Generation via Enals
5 Activated Esters as Azolium Enolate Precursors
6 Conclusions and Outlook
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References
- 1 Arduengo AJ, Harlow RL, Kline M. J. Am. Chem. Soc. 1991; 113: 361
MissingFormLabel
- 2 Igau A, Grutzmacher H, Baceiredo A, Bertrand G. J. Am. Chem. Soc. 1988; 110: 6463
MissingFormLabel
- 3 Wanzlick HW. Angew. Chem., Int. Ed. Engl. 1962; 1: 75
- 4 Ukai T, Tanaka R, Dokawa T. J. Pharm. Soc. Jpn. 1943; 63: 296
MissingFormLabel
- 5a Breslow R. J. Am. Chem. Soc. 1958; 80: 3719
MissingFormLabel
- 5b Breslow R, Schmuck C. Tetrahedron Lett. 1996; 37: 8241
- 6 Lapworth A. J. Chem. Soc., Trans. 1903; 83: 995
MissingFormLabel
- 7 Stetter H. Angew. Chem., Int. Ed. Engl. 1976; 15: 639
- 8a Ryan SJ, Candish L, Lupton DW. J. Am. Chem. Soc. 2009; 131: 14176
MissingFormLabel
- 8b Candish L, Lupton DW. Org. Lett. 2010; 12: 4836
- 8c De Sarkar S, Studer A. Angew. Chem. Int. Ed. 2010; 49: 9266
MissingFormLabel
- 8d Kaeobamrung J, Mahatthananchai J, Zheng P, Bode JW. J. Am. Chem. Soc. 2010; 132: 8810
MissingFormLabel
- 8e Zhu Z.-Q, Xiao J.-C. Adv. Synth. Catal. 2010; 352: 2455
MissingFormLabel
- 8f Biswas A, Sarkar SD, Fröhlich R, Studer A. Org. Lett. 2011; 13: 4966
- 8g Mahatthananchai J, Zheng P, Bode JW. Angew. Chem. Int. Ed. 2011; 50: 1673
- 8h Sun F-G, Sun L-H, Ye S. Adv. Synth. Catal. 2011; 353: 3134
MissingFormLabel
- 8i Wanner B, Mahatthananchai J, Bode JW. Org. Lett. 2011; 13: 5378
- 8j Biswas A, De Sarkar S, Tebben L, Studer A. Chem. Commun. 2012; 48: 5190
- 8k Mahatthananchai J, Kaeobamrung J, Bode JW. ACS Catal. 2012; 2: 494
- 8l Samanta RC, Maji B, De Sarkar S, Bergander K, Fröhlich R, Mück-Lichtenfeld C, Mayr H, Studer A. Angew. Chem. Int. Ed. 2012; 21: 5234
- 8m Yao C, Wang D, Lu J, Li T, Jiao W, Yu C. Chem.−Eur. J. 2012; 18: 1914
- 9a Enders D, Niemeier O, Henseler A. Chem. Rev. 2007; 107: 5606
MissingFormLabel
- 9b Marion N, Diez-Gonzalez S, Nolan SP. Angew. Chem. Int. Ed. 2007; 46: 2988
MissingFormLabel
- 9c Moore JL, Rovis T. Top. Curr. Chem. 2009; 291: 77
- 10a Biju AT, Kuhl N, Glorius F. Acc. Chem. Res. 2011;
- 10b Vora H, Rovis T. Aldrichimica Acta 2011; 44: 3
- 11a Phillips E, Chan A, Scheidt K. Aldrichimica Acta 2009; 42: 55
- 11b Nair V, Menon RS, Biju AT, Sinu CR, Paul RR, Jose A, Sreekumar V. Chem. Soc. Rev. 2011; 40: 5336
MissingFormLabel
- 12 Zhang Y.-R, He L, Wu X, Shao P.-L, Ye S. Org. Lett. 2007; 10: 277
- 13 Duguet N, Campbell CD, Slawin AM. Z, Smith AD. Org. Biomol. Chem. 2008; 6: 1108
MissingFormLabel
- 14a Duguet N, Donaldson A, Leckie SM, Douglas J, Shapland P, Brown TB, Churchill G, Slawin AM. Z, Smith AD. Tetrahedron: Asymmetry 2010; 21: 582
- 14b Duguet N, Donaldson A, Leckie SM, Kallstrom EA, Campbell CD, Shapland P, Brown TB, Slawin AM. Z, Smith AD. Tetrahedron: Asymmetry 2010; 21: 601
- 15a Cannizzaro CE, Strassner T, Houk KN. J. Am. Chem. Soc. 2001; 123: 2668
- 15b Cannizzaro CE, Houk KN. J. Am. Chem. Soc. 2004; 126: 10992
- 16 Tang K, Wang J, Hou Q, Cheng X, Liu Y. Tetrahedron: Asymmetry 2011; 22: 942
- 17 He L, Lv H, Zhang Y.-R, Ye S. J. Org. Chem. 2008; 73: 8101
MissingFormLabel
- 18 Wang X.-N, Shao P.-L, Lv H, Ye S. Org. Lett. 2009; 11: 4029
MissingFormLabel
- 19 Wang X.-N, Zhang Y.-Y, Ye S. Adv. Synth. Catal. 2010; 352: 1892
MissingFormLabel
- 20 Huang X.-L, Chen X.-Y, Ye S. J. Org. Chem. 2009; 74: 7585
MissingFormLabel
- 21 Wang T, Huang X.-L, Ye S. Org. Biomol. Chem. 2010; 8: 5007
MissingFormLabel
- 22 Jian T.-Y, He L, Tang C, Ye S. Angew. Chem. Int. Ed. 2011; 50: 9104
MissingFormLabel
- 23a Beecken H, Korte F. Tetrahedron 1962; 18: 1527
- 23b Jäger U, Schwab M, Sundermeyer W. Chem. Ber. 1986; 119: 1127
- 24 Lv H, Zhang Y.-R, Huang X.-L, Ye S. Adv. Synth. Catal. 2008; 350: 2715
- 25 Wang X.-N, Shen L.-T, Ye S. Org. Lett. 2011; 13: 6382
- 26 Wang X.-N, Shen L.-T, Ye S. Chem. Commun. 2011; 47: 8388
- 27 Shao P.-L, Chen X.-Y, Ye S. Angew. Chem. Int. Ed. 2010; 49: 8412
MissingFormLabel
- 28 Huang X.-L, He L, Shao P.-L, Ye S. Angew. Chem. Int. Ed. 2009; 48: 192
MissingFormLabel
- 29 Zhang Y.-R, Lv H, Zhou D, Ye S. Chem.–Eur. J. 2008; 14: 8473
- 30 Lv H, Chen X.-Y, Sun L.-h, Ye S. J. Org. Chem. 2010; 75: 6973
MissingFormLabel
- 31 Jian T.-Y, Shao P.-L, Ye S. Chem. Commun. 2011; 47: 2381
MissingFormLabel
- 32 Lv H, You L, Ye S. Adv. Synth. Catal. 2009; 351: 2822
MissingFormLabel
- 33 Shao P.-L, Chen X.-Y, Sun L.-H, Ye S. Tetrahedron Lett. 2010; 51: 2316
- 34 Shen L.-T, Shao P.-L, Ye S. Adv. Synth. Catal. 2011; 353: 1943
MissingFormLabel
- 35 Wang X.-N, Lv H, Huang X.-L, Ye S. Org. Biomol. Chem. 2009; 7: 346
MissingFormLabel
- 36 Concellón C, Duguet N, Smith AD. Adv. Synth. Catal. 2009; 351: 3001
- 37 Douglas J, Ling KB, Concellón C, Churchill G, Slawin AM. Z, Smith AD. Eur. J. Org. Chem. 2010; 5863
- 38 Vora HU, Wheeler P, Rovis T. Adv. Synth. Catal. 2012; 354: 1617
- 39a Chow KY.-K, Bode JW. J. Am. Chem. Soc. 2004; 126: 8126
MissingFormLabel
- 39b Reynolds NT, Read de Alaniz J, Rovis T. J. Am. Chem. Soc. 2004; 126: 9518
MissingFormLabel
- 39c Chan A, Scheidt KA. Org. Lett. 2005; 7: 905
MissingFormLabel
- 39d Sohn SS, Bode JW. Org. Lett. 2005; 7: 3873
MissingFormLabel
- 39e Zeitler K. Angew. Chem. Int. Ed. 2005; 44: 7506
- 39f Ling KB, Smith AD. Chem. Commun. 2011; 47: 373
MissingFormLabel
- 40 Mahatthananchai J, Bode JW. Chem. Sci. 2012; 3: 192
MissingFormLabel
- 41 Reynolds NT, Rovis T. J. Am. Chem. Soc. 2005; 127: 16406
MissingFormLabel
- 42 Vora HU, Rovis T. J. Am. Chem. Soc. 2010; 132: 2860
- 43 He M, Uc GJ, Bode JW. J. Am. Chem. Soc. 2006; 128: 15088
MissingFormLabel
- 44 He M, Beahm BJ, Bode JW. Org. Lett. 2008; 10: 3817
MissingFormLabel
- 45 Hayashi Y, Itoh T, Aratake S, Ishikawa H. Angew. Chem. Int. Ed. 2008; 47: 2082
- 46 Kobayashi S, Kinoshita T, Uehara H, Sudo T, Ryu I. Org. Lett. 2009; 11: 3934
- 47 Kawanaka Y, Phillips EM, Scheidt KA. J. Am. Chem. Soc. 2009; 131: 18028
MissingFormLabel
- 48 He M, Struble JR, Bode JW. J. Am. Chem. Soc. 2006; 128: 8418
MissingFormLabel
- 49 Kaeobamrung J, Kozlowski MC, Bode JW. Proc. Natl. Acad. Sci. U.S.A. 2010; 107: 20661
- 50 Fang X, Chen X, Chi YR. Org. Lett. 2011; 13: 4708
- 51 Wadamoto M, Phillips EM, Reynolds TE, Scheidt KA. J. Am. Chem. Soc. 2007; 129: 10098
- 52 Phillips EM, Roberts JM, Scheidt KA. Org. Lett. 2010; 12: 2830
MissingFormLabel
- 53 Phillips EM, Wadamoto M, Chan A, Scheidt KA. Angew. Chem. Int. Ed. 2007; 46: 3107
- 54 Li Y, Wang X.-Q, Zheng C, You S.-L. Chem. Commun. 2009; 5823
- 55 Lv H, Mo J, Fang X, Chi YR. Org. Lett. 2011; 13: 5366
- 56 Hao L, Du Y, Chen X, Jiang H, Shao Y, Chi YR. Org. Lett. 2012; 14: 2154
MissingFormLabel
- 57a Simal C, Lebl T, Slawin AM. Z, Smith AD. Angew. Chem. Int. Ed. 2012; 51: 3653
- 57b Belmessieri D, Morrill LC, Simal C, Slawin AM. Z, Smith AD. J. Am. Chem. Soc. 2011; 133: 2714
MissingFormLabel
- 57c Morrill LC, Lebl T, Slawin AM. Z, Smith AD. Chem. Sci. 2012; 3: 2088
For related processes using isothiourea-mediated catalysis to form ammonium enolates, see: