手性N-杂环卡宾催化的高对映选择性氮杂二烯狄尔斯-阿尔德反应

Highly enantioselective azadiene Diels-Alder reactions catalyzed by chiral N-heterocyclic carbenes.

作者信息

He Ming, Struble Justin R, Bode Jeffrey W

机构信息

Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106-9510, USA.

出版信息

J Am Chem Soc. 2006 Jul 5;128(26):8418-20. doi: 10.1021/ja062707c.

DOI:10.1021/ja062707c

PMID:16802805

Abstract

Highly enantioselective, N-heterocyclic carbene (NHC)-catalyzed aza-Diels-Alder reactions are described. A novel chiral triazolium salt based on the cis-1,2-aminoindanol platform serves as an efficient precatalyst for the NHC-catalyzed redox generation of enolate dienophiles that undergo LUMOdiene-controlled Diels-Alder reactions with N-sulfonyl-alpha,beta-unsaturated imines in good yields and with exceptional diastereo- and enantioselectivities (>99% ee). In contrast to uncatalyzed variants, this organocatalytic process proceeds at room temperature without stoichiometric reagents, producing synthetically valuable, enantiomerically pure cis-3,4-disubstituted dihydropyridinone products.

摘要

本文描述了高度对映选择性的N-杂环卡宾（NHC）催化的氮杂Diels-Alder反应。一种基于顺式-1,2-氨基茚满醇平台的新型手性三唑鎓盐作为一种有效的预催化剂，用于NHC催化的烯醇化物亲双烯体的氧化还原生成，该烯醇化物亲双烯体与N-磺酰基-α,β-不饱和亚胺发生LUMO二烯控制的Diels-Alder反应，产率良好，具有优异的非对映和对映选择性（对映体过量>99%）。与未催化的变体相比，这种有机催化过程在室温下进行，无需化学计量的试剂，生成具有合成价值的对映体纯的顺式-3,4-二取代二氢吡啶酮产物。