Deactivation of cationic CuI and AuI catalysts for A3 coupling by CH2Cl2: Mechanistic implications of the formation of neutral CuI and AuI chlorides

摘要

Care should be exercised when using CH2Cl2 as a solvent for reactions in which amines are a reagent, since undesirable deactivation of cationic copper(I) and gold(I) catalysts to form the corresponding inactive neutral chloride complexes [LMCl] (M=Cu or Au) can occur as a result of the generation of hydrogen chloride in the medium. CuI and AuI deactivation has been proved for the Mannich three-component coupling reaction. A series of CuI and AuI complexes with potential mechanistic implications were isolated and characterized by X-ray crystallography. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.