A New Bidentate Aminophosphole−Olefin Ligand for the Rhodium-Catalyzed Hydroformylation of Mono- and Disubstituted Olefins

Reaction of 1-bromo-2,5-diphenylphosphole with 10,11-dihydro-5 H -dibenzo[ b, f ]azepine resulted in the formation of the corresponding aminophosphole 3, which was structurally characterized. Reaction of 3 with [Rh 2 (μ - Cl) 2 (C 2 H 4 ) 4 ] and [Rh(COD) 2 ][BF 4 ] afforded the complexes [Rh 2 (μ - Cl) 2 ( 3 ) 2 ] ( 4 ) and [Rh(COD)( 3 )][BF 4 ] ( 5 ), respectively. In both complexes, characterized by NMR as well as by X-ray crystallography, ligand 3 behaves as a chelate through coordination of the phosphorus atom and the olefinic part of the ligand to the rhodium center. The activity of both complexes was tested in the hydroformylation of mono- and disubstituted olefins at 20 bar of CO/H 2 pressure. Complex 5 proves to be the most efficient catalyst.