Asymmetric Synthesis of Homoallylic Alcohols Featuring Vicinal Tetrasubstituted Carbon Centers via Dual Pd/Photoredox Catalysis

Abstract

Dual palladium/photoredox-catalysis provides an effective method for the asymmetric synthesis of vicinal a,b-tri/tetra- or a,b-tetra-substituted homoallylic alcohols. Regio- and enantioselective decarboxylative allylic alkylation of vinyl cyclic carbonates is reported using Hantzsch type esters as radical precursors. The developed methodology combines the use of versatile and accessible reagents and can be operated under mild reaction conditions giving the target molecules in appreciable to good yields, high branch-selectivity and appreciable enantiomeric ratios of up to 94:6. This protocol marks a rare example of the use of prochiral electrophiles for the creation of vicinal congested carbon centers.

Recent Advances in Decarboxylative Conversions of Cyclic Carbonates and Beyond

“…The same group also proved the efficiency of a catalytic system that merges photoredox and Pd catalysis in building quaternary carbons from vinyl cyclic carbonates via the use of Hantzsch-type esters as radical precursors (Scheme 12 ). 19…”