叔膦和氮杂环卡宾协同催化环化反应研究

Developing novel synthetic methods and strategies to realize functional group transformations in an atom-economical way and construct complex molecules concisely is the ultimate goal in modern organic chemistry. Recently, organocatalysis especially phosphine and N-heterocyclic carbenes (NHCs) have attracted considerable attention due to their unique activation patterns. And tremendous elegant transformations have been reported which are catalyzed by phosphine or NHCs. Now, we are seeking to develop a dual catalytic system which would take both phosphine catalyst and NHCs catalyst to achieve new activation patterns. Compared with traditional catalytic system, this cooperative catalytic system would allow us to break the limitations of single catalytic system and access complex molecules in one single step from simple and easily available starting materials. The described cooperative catalysis here could provide a straightforward, highly efficient, atom-economic, and green method for the access of heterocyclic compounds, which should be valuable for organic synthesis.

发展高效的合成策略，从而实现功能性分子简洁、绿色的构建，是当代有机化学领域核心目标。近年来，叔膦和氮杂环卡宾作为有机小分子催化剂，由于其独特的活化模式受到科研人员的广泛关注。以往基于单一叔膦或者氮杂环卡宾催化的反应已经取得令人瞩目的成就。现在我们致力于发展叔膦和氮杂环卡宾的双催化方法，这种叔膦和氮杂环卡宾的协同催化模式可以突破以往单一催化剂体系的局限性，实现从简单易得的起始原料出发，通过一步反应直接合成出结构复杂的目标分子。相比传统的多步合成法，本项目拟发展的杂环化合物合成法仅需要一步，是一种高效、绿色和原子经济的方法。

氮杂环卡宾（NHC）作为一类具有独特反应活性的有机小分子催化剂，近年来被广泛应用于各种具有复杂结构化合物的不对称催化合成。α-溴代肉桂醛和吲哚-2-甲基-3-甲醛衍生的不饱和二氰基类化合物在手性氮杂环卡宾催化下，成功合成手性四氢咔唑衍生物；利用金和氮杂环卡宾两种催化相结合，成功的实现了金和氮杂环卡宾接力催化关于isatin衍生的不饱和醛和烯炔酰胺的不对称串联(4+3)环加成反应。环化反应主要包括：烯炔酰胺和硫叶立德在金属催化剂调控下合成氮杂和氧杂七元环化合物；烯炔酰胺和硫叶立德在金催化和氢氧化锂作用下合成2-吡喃酮衍生物；硫叶立德和苯并三唑的(5+1)环化合成1,2,4-苯并三嗪类衍生物。