氮杂环卡宾催化碳-碳不饱和键反应研究

Organic reaction generally occurs between an electrophile and a nucleophile, while carbene catalysts could reverse the polarity of an electrophile to a nucleophile (umpolung) and thus realize the reaction between two nucleophiles. With its unique property, carbene catalysis received extensive attention and met great succuess in recent years. Being one of the most important functional group, carbon-carbon unsaturated bond presents widely in a number of organic molecules and plays vital role in chemical transformations. However, the N-heterocyclic carbene (NHC)-catalyzed reactions of carbon-carbon unsaturated bond are rarely reported. Although Fu and our group have independently reported the first intra- and intermolecular NHC-catalyzed reactions of carbon-carbon unsaturated bond, the substrate scope and types of reactions are still very limited, thus the related research on NHC-catalyzed reaction of carbon-carbon unsaturated bond is a challenge but highly desired. We propose to synthesize bifunctional NHCs, such as NHC-hydrogen bonding catalysts, NHC-Lewis acid catalysts to enhance the interaction between the catalyst and substrate, and develop the bifunctional NHC-catalyzed reactions of carbon-carbon unsaturated bond,including the alpha- or beta- functionalization reaction of Michael acceptors, cyclization reactions of alkenes and cumulenes. The research will develop several novel, efficient and green NHC-catalyzed reactions of carbon-carbon unsaturated bonds, providing new methedologies of catalytic chemical transformations, and thus advance the science of catalysis.

有机反应通常是亲电试剂与亲核试剂间的反应，而卡宾催化能将亲电试剂"极性反转"为亲核试剂，实现两个亲核试剂间的反应。由于这一独特性质，近年卡宾催化受到广泛关注，取得了长足的发展。碳-碳不饱和键广泛存在于多种有机分子，是有机分子转化最重要的官能团之一。然而，氮杂环卡宾催化的碳-碳不饱和键反应却少有报道。我们和G.C.Fu小组先后分别报道了首例分子间及分子内的氮杂环卡宾催化的碳-碳不饱和键的反应，但反应底物范围、反应种类非常有限，相关研究亟待突破。我们拟通过发展氢键-卡宾催化剂、路易斯酸-卡宾催化剂等双官能团卡宾催化剂，增强催化剂与底物作用，实现卡宾催化多种底物的碳-碳不饱和键反应，如Michael受体alpha-或beta-位反应、烯烃及累积烯烃的环化反应等。研究有望实现若干新颖、高效、绿色的氮杂环卡宾催化碳-碳不饱和键反应，开辟催化转化新体系，促进催化科学发展。

碳-碳不饱和键是有机分子的基本官能团之一，碳-碳不饱和键的转化反应在有机反应中占有重要地位。通过羟基-卡宾双功能催化剂以及路易斯酸与卡宾协同催化等，我们实现了系列碳-碳不饱和键的转化反应。(1)实现了卡宾催化硝基烯烃与氧杂二烯的[4+2]环化反应以及与偶氮化合物的aza-MBH反应。(2)实现了卡宾催化不饱和羧酸和α-氨基酮的[3+2]环化反应，以及和环状酮亚胺[3+3]环化反应。(3) 通过氢键-卡宾催化，实现烯酮与靛红亚胺的不称[2+2]环化反应；以及橙酮与烯醛反应的[3+4]环化反应。(4)通过手性卡宾及氯化锂作为路易斯酸共同催化，实现烯醛与γ,δ-不饱和丙二酸酯串联环化得到并环δ-内酯化合物。项目发表SCI论文19篇，毕业博士研究生7名。发展的氮杂环卡宾催化剂收录于《Encyclopedia of Reagents for Organic Synthesis》工具书。