Tandem hydroformylation-hydrogenation of 1-decene catalyzed by Rh-bidentate bis(trialkylphosphine)s.

A series of 2,2'-bis[(dialkylphosphino)methyl]biphenyls (alkyl-BISBIs) were synthesized and applied to the tandem hydroformylation-hydrogenation of 1-decene. The alkyl-BISBI ligands with "small" primary alkyl groups such as methyl or n-hexyl groups on the phosphorus atoms provided 1-alkanols selectively, whereas those with larger alkyl groups such as isopropyl or neopentyl groups showed much lower conversion from alkanals to alkanols. Observation of rhodium complexes of the BISBI-type ligands under H(2)/CO atmosphere revealed that the presence of a stable [RhH(CO)(2)(ligand)] species seems to be less favorable for the second step, the hydrogenation of aldehydes.