Manuel Iglesias

2 a and 2 b , [Ir(CI)(COD)(NHC)] (COD=1,5‐cyclooctadiene), have been prepared via transmetallation from NHC−Ag complexes. [Rh(CI)(COD)(NHC)] ( 4 ) was prepared analogously. [Ir({κ‐ C , N ‐(NHC‐acetamide−1H)}(COD)] ( 3 c ) has been synthesized via transmetallation from the deprotonated NHC−Ag complex. [IrCp*({κ‐ C , N ‐(NHC‐acetamide−1H)}] ( 5 ) (Cp*=pentamethylcyclopentadienyl), has been obtained analogously. [Ir(CI)(CO) 2 (NHC)] ( 6 ) and [Ir({κ‐ C , N ‐(NHC‐acetamide−1H)}(CO) 2 ] ( 7 ) have been prepared by carbonylation of 2 b and 3 c , respectively. The catalytic activity of these complexes has been evaluated in the dehydrogenation of formic acid, under solventless conditions, in the presence of water as a cosolvent, and in a 5 : 2 HCOOH/Et 3 N mixture, with the best TOF values being obtained in the case of the latter. Stoichiometric experiments suggest COD hydrogenation as the preactivation step.