Preparation of allylboronates by Pd-catalysed borylative cyclisation of dienynes.

Reaction of a variety of dienynes with bis(pinacolato)diboron catalysed by Pd bis(trifluoroacetate) affords allylic boronates containing five or six membered carbo- or heterocycles, by concomitant formation of one C-C and one C-B bonds. Resulting allylboronates can be employed for a variety of subsequent transformations.