Ring-Opening of Vinylcyclopropane-1,1-dicarboxylates by Boronic Acids under Ligandless Palladium Catalysis in Neat Water

We report a highly efficient ring-opening reaction of vinylcydopropanes by boronic acids in water, using palladium nanoparticles formed from Pd(OAc)(2) under ligandless conditions. Unsubstituted vinylcydopropanes provide linear addition products with high selectivity, while a switch in regioselectivity to branched products is observed for aryl-substituted vinylcydopropanes.