Brønsted acids of anionic chiral Co(iii) complexes as catalysts for the stereoselective synthesis of cis-4-aminofuranobenzopyrans

Abstract

A highly enantioselective interrupted Povarov reaction of salicylaldimines and 2,3-dihydrofuran was developed, through the elegant Brønsted acid catalysis of anionic chiral Co(III) complexes. This reaction affords the cis-4-aminofuranobenzopyran derivatives with up to 95% yield, >20 : 1 dr and 96 : 4 er. Moreover, a one-pot three-component procedure of salicylaldehydes, anilines, and 2,3-dihydrofuran proves to be successful, with higher reaction efficiency.