Enantioselective Formal [3 + 1 + 1] Cycloaddition Reaction by Ru(II)/Iminium Cocatalysis for Construction of Multisubstituted Pyrrolidines
作者:Mingfeng Li、Rui Chu、Jianghui Chen、Xiang Wu、Yun Zhao、Shunying Liu、Wenhao Hu
DOI:10.1021/acs.orglett.7b00055
日期:2017.3.17
A Ru(II)/iminium cocatalyzed asymmetric formal [3 + 1 + 1] cycloaddition reaction of diazoacetophenones, anilines, and enals is disclosed to construct multisubstituted pyrrolidines in one step with excellent diastereoselectivity and enantioselectivity. The reaction mechanism was postulated as a successful trapping of Ru(II)-associated ammonium ylides via a selective 1,4-addition to chiral amine activated
揭示了重氮基苯乙酮,苯胺和Enals的Ru(II)/亚胺共催化的不对称形式[3 +1 +1]环加成反应,可在一步中以优异的非对映选择性和对映选择性构建多取代的吡咯烷。推测该反应机理是通过选择性地将1,4-加成加入手性胺活化的烯醛中,然后通过串联氮杂-醛醇缩合工艺成功捕获了Ru(II)-相关的铵化铵。对照实验和理论密度泛函理论研究表明,可逆的NaOAc促进的aza-aldol过程导致非对映体转化,从而提供了稳定的产物。