Sila-Morita-Baylis-Hillman reaction of arylvinyl ketones: overcoming the dimerization problem.

Arylvinyl ketones, under Morita-Baylis-Hillman (MBH) reaction conditions, produce a mixture of dimerization products. We propose a solution to this problem: a sila-MBH reaction. This cascade reaction involves addition of phosphine catalyst to arylvinyl ketones, trapping of the forming beta-silylenolate with aldehyde, followed by a 1,3-Brook rearrangement to give the Si-MBH adducts in good to excellent yields.