Palladium-Catalyzed Cross-Coupling Reactions with Zinc, Boron, and Indium Exhibiting High Turnover Numbers (TONs):  Use of Bidentate Phosphines and Other Critical Factors in Achieving High TONs^†

Abstract

Palladium-catalyzed reactions of unsaturated organozincs with aryl or alkenyl iodides can exhibit turnover numbers (TONs) over 105 (>70% product yields). Under the conditions employed, Zn, B, and In appear to be the three most favorable metals, followed by Al(Zn) and Zr(Zn), whereas TONs observable with Sn, Cu, and Mn have been significantly lower