Rhodium-catalyzed conjugate addition-enantioselective protonation: the synthesis of alpha,alpha'-dibenzyl esters.

Alpha-benzyl acrylates, which are conveniently prepared from the corresponding aldehydes, can be employed as substrates in a tandem rhodium-catalyzed conjugate addition-enantioselective protonation protocol to afford enantiomerically enriched alpha,alpha'-dibenzyl esters. The synergistic effect of enantiopure ligand and proton source was rapidly optimized with use of a microwave reactor.