Diphosphonite

Note 1 PEPQ 4,4 -biphenylylene diphosphonite components retained Peak 1 877.5 ... 

The asymmetric hydrogenation of quinoline continues to be of interest. Li et al. reported the asymmetric hydrogenation of a variety of 2-substituted-quinolines to the corresponding tetrahydroquinolines using an Ir-catalyst with a BINOL-derived diphosphonite ligand... 

Subsequently, it was shown that rhodium complexes derived from diphosphi-nites, diphosphonites, and diphosphites - as well as hybrid ligands - are similarly active and selective to diphosphines [46 i],... 

The fluorous alkylphosphines 2 [8, 12] and 3 [8, 13], containing one or two perfluoroalkyl tails, respectively, have also been prepared. Partition coefficients of the chiral fluorous monophosphines 3a-b were found to be lower than the values measured for the corresponding phosphines 1, which contain one extra perfluoroalkyl tail [13], In addition, fluorous phosphinites, phosphonites and phosphites 4a-e and diphosphonite 5 have become available [8, 14]. 

Figure 1.14 Generation of supramolecular catalysts for asymmetric hydrogenation (a) Assembly of heterodimeric chelating ligands, (b) Structure of the optimal rhodium-diphosphonite complex for asymmetric hydrogenation (other ligands from the metal center omitted for clarity), (c) Enantioselective hydrogenation of functionalized alkenes.

A chiral diphosphonite, derived from BINOL (18) and with an achiral diphenyl ether backbone, is an excellent ligand for the iridium-catalysed asymmetric hydrogenation of quinolines. Enantioselectivities ranging from 90 to 94% were obtained.343... 

Reetz MT, Li X (2006) Asymmetric hydrogenation of quinolines catalyzed by iridium complexes of BINOL-derived diphosphonites. Chem Commun May 28 2159-2160... 

Irgafos P-EPQ Tetrakis(2,4-di-tert-butylphenyl)-4,4 -biphenylene diphosphonite 38613-77-3... 

The macrocyclic diphosphonite 25 was obtained in good yield from phenylbis-(diethylamino)phosphine. A new calix[4]arene tetrakis(dimethylphosphinite) (26) has been synthesised and its X-ray crystal structure determined. Both in... 

PtC=C and Pi C=C-C 13C chemical shifts were reported for (92) and related complexes.428 A typical 195Pt resonance was observed (—2180 ppm) for (93).429 A detailed analysis of and 13C resonances (from 2-D COSY and 13C, HMQC experiments) has been made for (94) and related systems.430 and 31P 1H NMR spectra for cz s-[PtCl L-K3C,P,P ], where L = sterically constrained diphosphonite ligands, gave characteristic Pt-P coupling constants.431 31P NMR spectroscopy was used to differentiate the isomers (95) and (96).432... 

Reetz and Li studied asymmetric hydrogenation of quinolines using iridium complex with a chiral BINOL derived diphosphonite ligand with an achiral diphenyl ether backbone as catalyst, achiral P ligands serving as possible additives (Scheme 10.7) [9]. Under the optimized conditions, 2 substituted and... 

Calixarene phosphorus derivatives continue to be studied for their intriguing properties. New tervalent examples are the calix[4]arene diphosphonite (43), the calix[6]arene diphosphite (44), and a tetra-phosphoramidite of a calix[4]resorci-nolarene. ... 

Typical processing stabilizers for polypropylene and butylated hydroxy-toluene (BHT) as the primary antioxidant and phosphates and phosphonates as secondary antioxidants. Examples of the latter that are commonly used are tetrakis-(2,4-di-terr-butyl-phenyl)-4-4 -bisphenylylenediphosphonite, distearyl-pentaerythrityl-diphosphonite, tris-(nonylphenyl)-phosphite, tris-(2,4-di-teft-butyl-phenyl)-phosphite and bis(2,4-di-ferr-butyl-phenyl)- pentaerythrityl-diphosphite. In commercial polypropylenes, phosphorous compounds are always used together with a sterically hindered phenol. The compounds are commonly added in concentrations between 0.05 and 0.25%. 

The P-Pt coupling data for the platinum- phosphonite complexes published in the literature have been reviewed by Vlugt et and the 7ppt couplings for two new complexes containing novel, sterically constrained diphosphonite ligands with 2-tert-butyl-phenolate and 2,2 -dioxo-3,3 -di-tert-butyl-5,5 -dimethoxy-1,1 -biphenyl groups have been measured by them. 

Non-hydrolyzable divalent metal oxides or sulfides, such as zinc oxide or zinc sulfide, are good stabilizers for poly(aryl ether sulfone)s. Organic aromatic phosphite and diphosphonite compounds were used as stabilizers. These compounds are shown in Figure 6.4. 

Figure 6.4 Phosphorous-based Stabilizers. Mark 2112 Tris(2,4-di-ferf-butyl phenyl) phosphite, Sandostab -P-EPQ Tetrakis(2,4-di-tert-butyl phenyl)-4,4-bi-phenylene diphosphonite ...

Tetrakis(2,4-di-terf-butyl phenyl)-4,4,-biphenylene diphosphonite, 230 Santowax R Mixed terphenyls, 230 SapronTM S SMA copolymer, 166 Schulatec PPS PolyCphenylene sulfide), 198 Selar PA3426 PA 6 T/I Poly(amide), 416 Sepharose CL... 

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