Suzuki–Miyaura coupling of phosphinoyl-α-allenic alcohols with arylboronic acids catalyzed by a palladium complex “on water”: an efficient method to generate phosphinoyl 1,3-butadienes and derivatives

Abstract

We report here the first palladium-catalyzed Suzuki–Miyaura couplings of phosphinoyl-α-allenic alcohols with arylboronic acids “on water” without phase-transfer catalysts or additives. This new methodology provides a novel approach to generate phosphinoyl 1,3-butadienes and derivatives with medium to excellent yields. A mechanism via initial C(sp³)–OH bond cleavage of the substrate to form π-allyl-palladium intermediates, and transmetallation with arylboronic acid, followed by reductive elimination to afford the product, is proposed.