Umpolung Chemo- and Regioselective Cascade Addition of Diethylzinc to α-Diketones Followed by Intramolecular Michael Reaction: Stereoselective Synthesis of Highly Substituted 1- Indanones.

Abstract

Herein we report an efficient stereoselective umpolung 1,2-addition of Et2Zn onto α-diketones followed by intramolecular cascade Michael cyclization. This strategy effectively delivers a broad range of substituted 1-indanones in excellent yields in a chemo- and regioselective fashion. Additionally, we performed a variety of synthetic transformations on the 1-indanone products. Furthermore, a hitherto-unexplored asymmetric variant of this methodology that provides up to 94:6 er using an easily accessible cinchona alkaloid ligand has been addressed.