Regioselective and Enantioselective Domino Aldol-Oxa-Michael Reactions to Construct Quaternary (Chroman) Stereocenters

An asymmetric domino aldol-oxa-Michael reaction of salicylaldehydes and ,-disubstituted ,-unsaturated aldehydes has been developed by using dienamine-mediated catalysis. The developed strategy leading to the stereoselective and regioselective formation of novel chroman derivatives with quaternary (chroman) stereocenters is presented. Particularly, salicylaldehydes with variously substitution patterns dominate the efficient construction of the chroman derivatives with high molecular complexity and skeletal diversity in excellent diastereo- and enantioselectivities.