Efficient kinetic resolution of racemic α-quaternary carboxylic acids via bromolactonization catalyzed by a BINOL-derived bifunctional sulfide

The catalytic kinetic resolution of racemic α-chiral carboxylic acids is an effective strategy for accessing optically active α-chiral carboxylic acid derivatives. While efficient catalytic kinetic resolutions of α-tertiary carboxylic acids have been well-established, the development of effective methods for the catalytic kinetic resolution of α-quaternary carboxylic acids bearing an all-carbon quaternary α-stereocenter remains a significant challenge. To accomplish this challenging project, we herein report an efficient kinetic resolution of α-quaternary carboxylic acids via a BINOL-derived chiral bifunctional sulfide-catalyzed bromolactonization, which produces α,γ-bis-quaternary γ-butyrolactones in high stereoselectivity.