Funktionelle Phosphane: Part X. Die homogene Hydrierung von Ketonen und α,β-ungesättigten Carbonylverbindungen mit 2-(Diphenylphosphanyl)anilido-Komplexen des Iridiums und Rhodiums als Katalysatoren. Molekülstrukturen von [Rh(PPh3)2(2-Ph2PC6H4NH-κN,κP)] u

The catalytic hydrogenation of saturated and unsaturated ketones and aldehydes in the presence of [Ir(CO)(PPh3)(2-Ph2PC6H4NR-κN,κP)] (R=H: 1; R=Me: 2), [Rh(CO)(PPh3)(2-Ph2PC6H4NR-κN,κP)] (R=H: 3; R=Me: 4), [Rh(PPh3)2(2-Ph2PC6H4NH-κN,κP)] (5), and [Ir(CO)(PPh3)(2-Ph2PC6H4N{C(O)camph-(1S)}-κN,κP)] (6, C(O)camph-(1S)=(1S)-camphanoyl) has been investigated. Out of the complexes tried, only 1 showed significant activity for the reduction of the carbonyl group. Evidence is presented that the catalytic cycle is entered by the formation of the cis-(H,H)-cis-(P,P)-dihydride [IrH2(CO)(PPh3)(2-Ph2PC6H4NH-κN,κP)] (9a) which can be observed by 1H NMR under 45 bar H2. The homogeneous hydrogenation of five α,β-unsaturated carbonyl compounds (crotonaldehyde, ethyl vinyl ketone, 2-cyclohexen-1-one, benzylideneacetone, and benzylideneacetophenone), in the presence of 1, proceeded with chemoselectivities for the corresponding allylic alcohols varying between zero for EtC(O)CHCH2 and 77–78% for PhCHCHC(O)Me and MeCHCHCHO, respectively. Complexes 1 and 5 were fully characterized by X-ray structure analysis.