All-Carbon Quaternary Stereocenters α to Azaarenes via Radical-Based Asymmetric Olefin Difunctionalization

A radical-based asymmetric olefin difunctionalization strategy for rapidly forging all-carbon quaternary stereocenters alpha to diverse azaarenes is reported. Under cooperative photoredox and chiral Bronsted acid catalysis, cyclopropylamines with alpha-branched 2-vinylazaarenes can undergo a sequential two-step radical process, furnishing various valuable chiral azaarene-substituted cyclopentanes. The use of the rigid and confined C-2-symmetric imidodiphosphoric acid catalysts achieves high enantio- and diastereo-selectivities for these asymmetric [3 + 2] cycloadditions.