Developing Phospha-Stork Chemistry Induced by a Borane Lewis Acid

Bulky vinyl phosphanes undergo carbon-carbon coupling with aryl aldehydes with the help of the Lewis acid B(C6F5)(3) to give isolable methylene phosphonium products. Dimesityl(vinyl) phosphane undergoes a phospha-Stork reaction with bulky enones efficiently catalyzed by B(C6F5)(3) to eventually yield the corresponding substituted cyclobutane products.