Regiospecific Carbonylative Annulation of Iodophenol Acetates and Acetylenes To Construct the Flavones by a New Catalyst of Palladium−Thiourea−dppp Complex

[reaction: see text] Regiospecific carbonylative annulation of o-iodophenol acetates and acetylenes mediated by palladium-thiourea-dppp complex in the presence of base at 40 degrees C under a balloon pressure of CO generates diversified flavones in high yields. This newly developed synthetic technology provides a highly efficient method for potential application to the combinatorial synthesis of those heterocycles on the solid support.