Sol Metlin

Preparation and properties of rhodium(I) complexes of phosphinated poly(methylsiloxanes)

Abstract A series of poly(methylsiloxanes) that contain carbon-functional diphenylphosphine groups were prepared and subsequently treated with RhCl(CO)(PPh 3 ) 2 to produce polymer-attached chlorocarbonylrhodium(I) complexes. The materials are soluble in a variety of organic solvents, and are easily precipitated from solution by the addition of excess methanol. The polymer complex A derived from a phosphinated silicone polymer containing one PPh2 group per 60 siloxy units has a molecular weight of 21000 daltons and contains 0.8% Rh. In accord with its formulation, the polymer shows a ν(CO) at 1970 cm -1 and an ultraviolet absorption at 3625 A. Similar rhodium(I) complexes derived from phosphinated silicones containing one PPh 2 group per 20 (complex B) and 8 (complex C) siloxy units were also investigated. Complexes A and B catalyze the hydroformylation of hex-1-ene at 100°C, 1000 psi CO/H 2 pressure yielding the linear/branched heptaldehyde in a ratio of 0.9 with 95% selectivity and an overall conversion of 97% to products in 3 h. Although the hydroformylation conditions do not lead to depolymerization, both Rh and P are lost from the polymers and the actual catalyst appears to be a free rhodium carbonyl species. Complex C is a less active hydroformylation catalyst (14% aldehyde conversion, normal/branched ratio 1.7) and the polymer undergoes extensive degradation in the reaction.

The Mn2(CO)10 catalyzed hydrogenation and hydroformylation of olefins

Abstract Mn2(CO)10 catalyze the homogeneous hydrogenation of 1- and 2-octene. In the presence of carbon monoxide and hydrogen at temperatures up to 235°, it is also a homogeneous hydroformylation catalyst. Cyclohexene yields the expected product, cyclohexylmethanol, at 235°, but at 200° the major product is cyclohexylmethyl formate.

The 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.