Pd((R)-DTBM-SEGphos)Cl₂-catalyzed kinetic resolution of tertiary propargylic alcohols

We report here an asymmetric carboxylation reaction based on kinetic resolution of tertiary propargylic alcohols by identifying Pd((R)-DTBM-SEGphos)Cl2 as the pre-catalyst. A variety of optically active tertiary propargylic alcohols and tetrasubstituted 2,3-allenoic acids were obtained in good yields with excellent enantioselectivities. The salient features of this report include the use of readily available substrates, a readily available precatalyst, mild reaction conditions, remarkable functional group tolerance, gram-scale synthesis, and versatile synthetic transformations. Mass spectrometry experiments trapped some key intermediates, which revealed the mechanism.