Cp*Ir(NHC) complexes as highly versatile and efficient catalysts for the cross-coupling of alcohols and amines

Abstract

A comparative study on the catalytic activity of a series of Cp*Ir(NHC)Cl2 complexes in several C-O and C-N coupling processes implying hydrogen-borrowing mechanisms has been performed. The compound Cp*Ir(InBu)Cl2 (InBu = 1,3-di-n-butylimidazolylidene) showed to be highly effective in the cross coupling reactions of amines and alcohols, providing high yields in the production of unsymmetrical ethers and N-alkylated amines. A remarkable feature is that the processes were carried out in the absence of base, phosphine or any other external additive. A comparative study with other well known catalysts, such as Shvo’s catalyst, is also reported