An Intramolecular Umpolung Cascade Kukhtin–Ramirez Reaction/Michael Addition-Initiated Cyclization: Stereoselective Synthesis of Tetrasubstituted Cyclopropane Fused 1-Indanones

Abstract

Herein, we disclose a fascinating highly stereoselective P(NMe 2 ) 3 mediated intramolecular deoxygenative umpolung cascade Michael addition-initiated cyclopropanation with a diverse substrate adaptability. This methodology creates a new horizon for expedient access to valuable 6,5,3-fused scaffolds having an all-carbon quaternary stereocenter via Kukhtin–Ramirez (K–R) adduct formation, with excellent diastereoselectivity and yields under metal-free ambient conditions. A few functional group transformations have also been performed successfully. Additionally, an asymmetric catalytic attempt using ( R )-(+)-H8-BINOL has delivered good enantioselectivity.

Topics & Concepts