PREPARATION AND CATALYTIC HYDROFORMYLATION ACTIVITY OF SOME HALOCARBONYLRHODIUM(I) COMPLEXES CONTAINING PHOSPHINOALKYLORGANOSILICON LIGANDS

The synthesis and properties of a series of trans-halocarbonylrhodium(I) complexes containing the phosphinoalkylorganosilicon ligands Me3SiCH2PPh2, Me3Si(CH2)3PPh2, and PPh2CH2(Me)Si(OSiMe2)3O have been investigated. The complexes could be prepared by an exchange reaction involving RhCl(CO)(PPh3)2 and the organosilicon ligands or in better yields by the reaction of Rh2Cl2(CO)4 with the ligands. Iodorhodium derivatives were obtained as the exclusive products in the latter reaction if a small amount of LiI was present. The catalytic activity of RhCl(CO)(PPh2CH2SiMe3)2 was similar to that of RhCl(CO)(PPh3)2 in the hydroformylation of hex-1-ene at 100°C and 1000 psi pressure of H2/CO. The catalytic properties of the iodo derivatives RhI(CO)L2 [L = Me3SiCH2PPh2, Me3Si(CH2)3PPh2, and PPh2CH2(Me)Si(OSiMe2)3O] varied considerably, with RhI(CO)(PPh2CH2SiMe3)2 producing an unexpectedly low linear/branched aldehyde product ratio. © 1979.