Rhodium-Catalyzed Regio- and Diastereoselective Hydroarylation of Allenes: An Unprecedented Ene Reaction

A rhodium-catalyzed nucleophilic addition of α-acidic isocyanoacetamides to allenes for the selective formation of Z-vinyl-functionalized oxazoles as an unprecedented method for hydroarylation of allenes is described. Employing diverse isocyanoacetamides and allenes, a library of vinyl oxazoles is introduced in a stereo- and regiospecific fashion and moderate to high yields. Mechanistic investigations reveal that the reaction proceeds through a concise rhodium-catalyzed ene reaction followed by reductive elimination.