Rhodium containing cationic phosphines

Other protein-rhodium conjugates containing cationic rhodium catalysts have also been prepared using bis(diphenylphosphino-ethyl)amino derivatives 5-7 and solutions of these bis(phosphine) ligands in the presence of carbonic anhydrase, a-chymotrypsin and bovine serum albumin (47). However, the exact nature of the complexes formed has not been discerned in any of these cases, and these latter enzyme-transition metal complexes evidently do not exhibit enantioselectivity in hydrogenation of a-acetamidoacrylic acid. 

Cationic Rhodium Compiexes Containing Aromatic Phosphines... 

The hydrogenation reaction is carried out with a substituted cinnamic acid. The acetamido group is of particular importance because it functions as a secondary complexation function in addition to the alkene functionality. In the first step the alkene co-ordinates to the cationic rhodium species (containing an enantiopure phosphine DIPAMP in Figures 4.4 and 4.5 with the chirality at phosphorus carrying three different substituents, Ph, o-An, CH2) for which there are several diasteromeric structures due to ... 

Other iodocarbonyl complexes might be present, depending on the CO pressure. In a further study of the water-gas shift reaction a large number of phosphine-containing rhodium complexes were investigated as catalysts. They were mainly either neutral or cationic carbonyl derivatives... 

Studies in Asymmetric Synthesis, Preparation, Reactivity, and Solid-State Structures of Cationic Rhodium Complexes Containing a Chiral Amino-phosphine or Aminoarsine Ligand... 

An additional access to chiral sulfonated phosphines was also described [13a,b]. The method is based on the acylation of chiral hydroxyphosphines with commercial o-sulfobenzoic anhydride and was demonstrated on a number of diphosphines based on the DIOP skeleton (Eq. 1). The chelating properties of the diphosphines were studied by preparation of cationic rhodium complexes. The presence of the o-sulfobenzoate group is thought not to influence the catalytic properties. Chiral phosphines containing a sulfonate group (e.g., 8) were also obtained from BPPM by acylation with trimellitic anhydride followed by treatment with sodium tauri-nate [13 c],... 

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