20491-53-6Relevant articles and documents
Parallels between Metal-Ligand Cooperativity and Frustrated Lewis Pairs
Habraken, Evi R. M.,Jupp, Andrew R.,Brands, Maria B.,Nieger, Martin,Ehlers, Andreas W.,Slootweg, J. Chris
, p. 2436 - 2442 (2019)
Metal ligand cooperativity (MLC) and frustrated Lewis pair (FLP) chemistry both feature the cooperative action of a Lewis acidic and a Lewis basic site on a substrate. A lot of work has been carried out in the field of FLPs to prevent Lewis adduct formation, which often reduces the FLP reactivity. Parallels are drawn between the two systems by looking at their reactivity with CO2, and we explore the role of steric bulk in preventing dimer formation in MLC systems.
Enantioselective addition of secondary phosphines to methacrylonitrile: Catalysis and mechanism
Sadow, Aaron D.,Togni, Antonio
, p. 17012 - 17024 (2005)
A highly enantioselective intermolecular hydrophosphination reaction is described. The (Pigiphos)-nickel(II)-catalyzed reaction of secondary phosphines and methacrylonitrile gives chiral 2-cyanopropylphosphines in good yield and high enantiomeric excess (ee's up to 94%; (R)-(S)-Pigiphos = bis{(R)-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl}cyclohexylphos phine). We propose a mechanism involving coordination of methacrylonitrile to the dicationic nickel catalyst followed by 1,4-addition of the phosphine, and then, rate-determining proton transfer. This mechanism is supported by (a) the experimentally determined rate law (rate = K[Ni][methacrylonitrile][t-Bu 2PH]), (b) a large primary deuterium isotope effect K H/KD = 4.6(1) for the addition of t-Bu2PH(D) at 28.3°C in toluene-d8, (c) the isolation and characterization of the species [Ni(K3-Pigiphos)(KN-methacrylonitrile)]2+, and (d) DFT calculations of model compounds.
N,N-BIS(2-DIALKYLPHOSPHINOETHYL)AMINE-BORANE COMPLEX AND PRODUCTION METHOD THEREFOR, AND METHOD FOR PRODUCING RUTHENIUM COMPLEX CONTAINING N,N-BIS(2-DIALKYLPHOSPHINOETHYL)AMINE AS LIGAND
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Paragraph 0164; 0165-0169, (2019/02/19)
The purpose of the present invention is to provide an N,N-bis(2-dialkylphosphinoethyl)amine-borane complex which is a ruthenium complex that exhibits excellent catalytic activity in a hydrogenation reaction, etc., and a production method therefor, and a method for efficiently producing a ruthenium complex containing N,N-bis(2-dialkylphosphinoethyl)amine as a ligand. The present invention is capable of efficiently producing an amine-borane complex (3) by reacting an oxazolidinone compound (1) with a dialkylphosphine-borane compound (2) in the presence of a base. The present invention is also capable of efficiently producing a ruthenium complex (5) by reacting the amine-borane complex (3) with a ruthenium compound (4) in the presence of an amine. (In the formula, a solid line, a dashed line, B, C, H, L1-L3, LG, n, N, O, P, Ru, X, and R1-R10 are as defined in the description.)
Rapid Metal-Free Formation of Free Phosphines from Phosphine Oxides
Provis-Evans, Cei B.,Emanuelsson, Emma A. C.,Webster, Ruth L.
supporting information, p. 3999 - 4004 (2018/09/21)
A rapid method for the reduction of secondary phosphine oxides under mild conditions has been developed, allowing simple isolation of the corresponding free phosphines. The methodology involves the use of pinacol borane (HBpin) to effect the reduction while circumventing the formation of a phosphine borane adduct, as is usually the case with various other commonly used borane reducing agents such as borane tetrahydrofuran complex (BH3?THF) and borane dimethyl sulfide complex (BH3?SMe2). In addition, this methodology requires only a small excess of reducing agent and therefore compares favourably not just with other borane reductants that do not require a metal co-catalyst, but also with silane and aluminium based reagents. (Figure presented.).
