767323-63-7

Upstream product

• 76189-55-4 (R)-(+)-2,2’-bis(diphenylphosphino)-1,1’-binaphthalene 
• 76144-87-1 2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl 
• 201230-82-2 carbon monoxide 

Relevant academic research and scientific papers

Stoichiometric and catalytic oxidation of BINAP by dioxygen in a rhodium(I) complex

The square planar complex (BINAP)Rh(CO)Cl (BINAP = 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) was synthesized from [Rh(COD)Cl]2 (COD = 1,5 cyclooctadiene) and BINAP under a CO atmosphere. It reacts with oxygen to form the square planar (BINAP(O))Rh(CO)Cl in approximately 50% yield, along with molar equivalents of free BINAP dioxide (BINAP(O)2) and CO2. The oxygen atom of the BINAP(O) was shown crystallographically to be trans to the CO ligand. In the presence of excess BINAP under CO/O2 gas mixtures, the reaction is catalytic with a TOF of 0.16 h-1 at ambient temperature in chloroform. The kinetics of this transformation were investigated and conditions for optimum selectivity for BINAP(O) formation suggested. A stoichiometric mechanism is proposed that involves initial formation of an O2 adduct, followed by oxygen atom transfer to both phosphorus atoms of BINAP or to one phosphorus atom and the CO ligand trans to it. These processes might be concerted, or stepwise with intermediate Rh=O species. To the best of our knowledge, this chemistry represents the first example of a reaction exhibiting oxygen atom addition from O2 either to both phosphorus atoms in a bisphosphine ligand or to one phosphorus atom and a CO ligand in the same complex.

Evaluation of C4 diphosphine ligands in rhodium catalysed methanol carbonylation under a syngas atmosphere: Synthesis, structure, stability and reactivity of rhodium(i) carbonyl and rhodium(iii) acetyl intermediates

The carbonylation of methanol to acetic acid is a hugely important catalytic process, and there are considerable cost and environmental advantages if a process could be designed that was tolerant of hydrogen impurities in the CO feed gas, while eliminating by-products such as propionic acid and acetaldehyde altogether. This paper reports on an investigation into the application of rhodium complexes of several C4 bridged diphosphines, namely BINAP, 1,4-bis(diphenylphosphino)butane (dppb), bis(diphenylphosphino) xylene (dppx) and 1,4-bis(dicyclohexylphosphino)butane (dcpb) as catalysts for hydrogen tolerant methanol carbonylation. An investigation into the structure, reactivity and stability of pre-catalysts and catalyst resting states of these complexes has also been carried out in order to understand the observations in catalysis. Rh(i) carbonyl halide complexes of each of the ligands have been prepared from both [Rh2(CO)4Cl2] and dimeric μ-Cl-[Rh(L)Cl]2 complexes. These Rh(i) carbonyl complexes are either dimeric with bridging phosphine ligands (dppb, dcpb, dppx) or monomeric chelate complexes. The reaction of the complexes with methyl iodide at 140 °C has been studied, which has revealed clear differences in the stability of the corresponding Rh(iii) complexes. Surprisingly, the dimeric Rh(i) carbonyls react cleanly with MeI with rearrangement of the diphosphine to a chelate co-ordination mode to give stable Rh(iii) acetyl complexes. The Rh acetyls for L = dppb and dppx have been fully characterised by X-ray crystallography. During the catalytic studies, the more rigid dppx and BINAP ligands were found to be nearly 5 times more hydrogen tolerant than [Rh(CO) 2I2]-, as revealed by by-product analysis. The origin of this hydrogen tolerance is explained based on the differing reactivities of the Rh acetyls with hydrogen gas, and by considering the structure of the complexes. The Royal Society of Chemistry.

Difluorphos, an Electron-Poor Disphosphane: A Good Match between Electronic and Steric Features

The π acidity makes the difference: The fluorinated diphosphane, difluorphos, is synthesized (see structure: purple = P, red = O, green = F, gray = C) and its stereoelectronic features are evaluated in theoretical and experimental studies. Its unusual π acidity explains the excellent results obtained with it in ruthenium-mediated asymmetric hydrogenation of fluorinated β-functionalized ketones. These results are better than those obtained with other biphenyl-based diphosphanes.