Synthesis of new rhodium complexes with a hemilabile nitrogen-containing bis(phosphinite) or bis(phosphine) ligand. Application to hydroformylation of styrene

Two new cationic rhodium(I) complexes with a hemilabile nitrogen-containing bis(phosphinite) or bis(phosphine) ligand have been prepared. 31P-NMR studies provide evidence that the ligands are coordinated to the metal in P,P-bidentate mode, whereas for the bis(phoshine)-based ligand, a P,N,P-tridentate mode is also possible to be found at low temperatures. The complexes were applied to the hydroformylation of styrene and displayed a high chemoselectivity for aldehydes with a very good branched/linear ratio.