Development of zinc borates designed for functionalized hard nucleophiles in the coupling reaction with allylic alcohol derivatives

Abstract

Zinc borates 3 (R T = aryl, alkenyl), prepared from the boronate esters 1 and MeZnCl, were developed for the title reaction. Thus, reaction of the allylic acetates 6a-c with the aryl borates 3a-f and the alkenyl borates 3g,h in the presence of NiCl 2(PPh 3) 2 (10 mol%) and DMI (10 equiv) at 40–50 °C afforded the coupling products 8a-o in good yields (Tables 1 and 2). Since MeZnCl is almost inert toward carbonyl groups, this method is applicable for the functionalized borates 3.