Syntheses, Characterizations, and Reactivity of Two Cu(I)-Amido Complexes: Proposed Intermediate in Cu(I)-Catalyzed Goldberg Reaction

Abstract

Reactions between dichloro-bridged copper(I) complexes and amides with different carbonyl substituents (CF₃, CH₃, and Ph) were reported. Two neutral Cu(I)-amido complexes, [Cu(Dppf)(MOAA)] (I) and [Cu(Dppf)(MOTFAA)] (II) (Dppf = 1,1'-bis(diphenylphosphino)ferrocene, MOAA and MOTFAA = deprotonated N-(4-methoxyphenyl) acetamide and N-(4-methoxyphenyl) trifluoroacetamide, respectively), were synthesized in moderate to good yield and characterized by element analysis, 1H NMR and X-ray crystallography method (СIF file CCDC no. 1015222 (I)). The results showed that the production of Cu(I)- amido complxes were influenced by carbonyl substituent in the order of Ph > CF₃ > CH₃. The substituent effect also appeared in the N-arylation reactions of I and II with iodobenzene, which generated another copper(I) complex Cu(Dppf)I (III) and two amides products [N-methyl-N-(4-methoxyphenyl) acetamide] (А) and [N-methyl-N-(4-methoxyphenyl) trifluoroacetamide] (B) in different yield. The formation and transformation of the Cu(I)-amido complexes could indicate their dynamiccompetency as the intermediates of Goldberg reaction.