Palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron with vinyl triflates β-substituted by a carbonyl group:: efficient synthesis of β-boryl-α,β-unsaturated carbonyl compounds and their synthetic utility

Cross-coupling reaction of bis(pinacolato)diboron with beta-(trifluoromethanes ulfonyloxy)-alpha, beta-unsaturated carbonyl compounds was carried out in the presence of PdCl2(PPh3)(2)-2PPh(3) (3 mol%) and KOPh in toluene or K2CO3 in dioxane for the synthesis of cyclic and acyclic beta-boryl-alpha,beta-unsaturated esters, amides, and ketones in high yields. The vinylboronates thus obtained readily participated in carbon-carbon bond formation such as cross-coupling with vinyl triflates and 1,4-addition to alpha,beta-unsaturated ketones. (C) 2003 Elsevier B.V. All rights reserved.