C–H Oxidation/Michael Addition/Cyclization Cascade for Enantioselective Synthesis of Functionalized 2-Amino-4H-chromenes

• DOI: 10.1021/acs.orglett.5b03148
• Publication Date: 2015-12-10T16:35:59Z
• Authors: Bo Wu; Xiang Gao; Zhong Yan; Mu-Wang Chen; Yong-Gui Zhou
• Keywords: Squaramide; Michael reaction; Cascade reaction; Methylene

A streamlined method for the enantioselective synthesis of 2-amino-4H-chromenes from readily available 2-alkyl-substituted phenols and active methylene compounds bearing a cyano group with up to 97% ee is presented. This reaction cascade procedure including manganese dioxide mediated C–H oxidation generation o-quinone methides bifunctional squaramide-catalyzed Michael addition/cyclization.