Asymmetric Catalytic [4+5] Annulation of ortho-Quinone Methides with Vinylethylene Carbonates and its Extension to Stereoselective Tandem Rearrangement

Abstract

Palladium-catalyzed asymmetric [4+5] annulation of ortho-quinone methides (o-QMs) with substituted vinylethylene carbonates (VECs) is described for the first time, giving a novel enantioselective approach to chiral nine-membered benzoheterocycles. Based on this designed [4+5] annulation, an unprecedented silica gel-promoted tandem rearrangement reaction featuring a unique asymmetric aromatic Claisen rearrangement is explored at room temperature, offering a new method for asymmetric construction of all-carbon quaternary stereocenters embedded in chiral functionalized homoallylic alcohols.

Keywords: [4+5] annulation; asymmetric catalysis; ortho-quinone methides; quaternary carbon; rearrangement.