Multiple Hydrogen-Bonding Bifunctional Thiourea-Catalyzed Asymmetric Dearomative [4 + 2] Annulation of 3-Nitroindoles: Highly Enantioselective Access to Hydrocarbazole Skeletons

• DOI: 10.1021/acs.orglett.7b02068
• Publication Date: 2017-08-15T17:26:28Z
• Authors: Deng-Feng Yue; Jian-Qiang Zhao; Xiao-Zhen Chen; Yan Zhou; Xiao-Mei Zhang; Xiao-Ying Xu; Wei-Cheng Yuan
• Keywords: Annulation; Reactivity

A method for the enantioselective construction of hydrocarbazole skeletons through dearomative [4 + 2] annulation 3-nitroindoles with Nazarov reagents is reported. The reactions use multiple hydrogen-bonding bifunctional thiourea as catalyst and are highly diastereo- (up to >20:1 dr >99% ee). protocol was demonstrated by preparative-scale experiment versatile conversion products. in plays a pivotal role reactivity stereoselectivity.