The preparation and properties of tris(triphenylphosphine)halogenorhodium(I) and some reactions thereof including catalytic homogeneous hydrogenation of olefins and acetylenes and their derivatives

Abstract

Bennett and Longstaff (ref. 16).

Homogeneous Hydrogenation of Unsaturated Carboxylic Acids Using Chlororhodate(I) Complexes and Rhodium(I) Diethylsulfide Complexes

“…A corresponding diphenylsulfide system was said to exhibit some activity, before decomposition of the catalyst again occurred (1 1). If the Rhl(olefin) complex is too stable, however, hydrogenation may not occur; this situation occurs in the case of attempted hydrogenation of tetracyanoethylene using Rh chlorides in DMA (1) and of tetrafluoroethylene using RhCl(PPh,), in benzene (12). An intimately related factor with these strong n-acid ligand systems is the increased electronic promotional energy necessary for the oxidative Hz addition (12).…”

Pioneering Perspectives on Asymmetric Hydrogenation

“…It was all made possible by Wilkinson's discovery that triphenylphosphine/Rh complexes catalyzed hydrogenation of olefins in solution. 3 Now, we are no longer dealing with catalysis on a metal surface but with a coordination compound in molecular dispersion. Thus, one could use the power of the synthetic chemist to vary structures without limit to optimize results in a more or less rational manner.…”

Origin of the formation of the 4‐butenyl end group in zirconocene‐catalyzed propylene polymerization

“…The formation of the dihydrido species RhCl(PPh 3 ) 2 H 2 is a reversible reaction involving hydrogen gas as a reactant. 34 Hydrogen was not flushed during the reaction to avoid hydrogenation of unsaturated groups, and so the hydride RhCl(PPh 3 ) 2 H 2 was expected to be reduced to RhCl(PPh 3 ) 3 during the reaction. This may explain the small change in the 4-butenyl/2-butenyl ratios with the reaction time.…”

“…The absorption of molecular hydrogen with RhCl(PPh 3 ) 3 in solution produced the transient dihydrido species RhCl(PPh 3 ) 2 H 2 after oxidative addition. 34 The reactant medium was prepared under an inert atmosphere in a 50-mL, round-bottom flask with a condenser on top. One gram of the polymer (iPP) was dissolved in 30 mL of dry toluene, and 0.5 mL of TIBA was added as a scavenger.…”