Pd-catalyzed regio- and enantioselective allylation of cyclic allylboronates

Abstract

A robust protocol for the palladium-catalyzed regio-and enantioselective allylic substitution of 6-membered cyclic boronate salts is reported, enabling efficient access to complex scaffolds possessing two distinct alkenes, a synthetic boron handle, and an allylic tertiary stereocenter. This methodology is characterized by high levels of stereoselectivity and regioselectivity across a wide range of substrates. The synthetic potential of this approach has been demonstrated by several transition metal-catalyzed selective derivatizations. Computational studies at a mixed UMA/DFT level of theory reveal that the reaction is governed by a Curtin-Hammett scenario, wherein reductive elimination from hetero-bis-σ-allyl palladium(II) intermediates constitutes the regio-and enantio-determining step of the process.