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.
Frost, C. G., Penrose, S. D., Lambshead, K., Raithby, P. R., Warren, J. E., & GleaveO, R. (2007). Rhodium-catalyzed conjugate addition-enantioselective protonation: The synthesis of alpha,alpha'-dibenzyl esters. Organic Letters, 9(11), 2119-2122. https://doi.org/10.1021/ol070603g