Rh and Ir complexes bearing -heteroscorpionates and their application in catalytic transfer hydrogenation

Equimolar treatment of the bis(pyrazol-1-yl)-phenylethanol ligand with [M(Cl) 3 (H 2 O) 3 ] precursors has been performed to obtain novel NNO -heteroscorpionate rhodium III ( 1 ) and iridium III ( 2 ) complexes. The structural features of 1 and 2 were determined by spectroscopic methods in solution and X-ray crystallography in the solid state. Complexes 1 and 2 are efficient catalysts for the transfer hydrogenation of ketones and aldehydes under low catalyst loadings. We report the synthesis, characterization, and catalytic performance of Rh III and Ir III complexes supported by N,N,O-heteroscorpionate ligands.