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

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. [ABSTRACT FROM AUTHOR]