Chemistry of iron complexes—VI. ESR, spectroscopic and other studies of complexes of iron(III) perchlorate and isothiocyanate with bis(tertiary phosphine/arsine oxides)
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P NMR spectroscopic analysis on photooxidation of 1,n‐bis(diphenylphosphino)alkanes with the aid of DFT calculations
作者:Shinro Yasui、Shoko Yamazaki
DOI:10.1002/poc.4021
日期:2020.4
Ph2P(═O)(CH2)nP(═O)Ph2. The oxidation of the diphosphine to the diphosphine monoxide took place according to first‐order kinetics with respect to the concentration of the diphosphine, the first‐order rate constant, kobs, being larger with increasing number of the methylene units in the spacer. The observation in kinetics is interpreted based on the conformation of the diphosphine radical cation intermediate initially
Intramolecular Stabilization of the Phosphine Radical Cation by the Second Phosphorus Atom during the Photooxidation of Diphosphines: <sup>31</sup>P NMR Spectroscopic Analysis
作者:Shinro Yasui、Shoko Yamazaki
DOI:10.1246/cl.141027
日期:2015.4.5
Diphosphines, Ph2P(CH2)nPPh2 1 (n = 1, 2, 3, 4, and 6), were photolyzed by a xenon lamp in air. The 31P NMR spectroscopic analysis of the reaction showed that 1 is oxidized, according to first-orde...
Evaluation of bifunctional chiral phosphine oxide catalysts for the asymmetric hydrosilylation of ketimines
作者:Christopher J.A. Warner、Sian S. Berry、Simon Jones
DOI:10.1016/j.tet.2019.130733
日期:2019.12
A series of bifunctional phosphine oxides have been prepared and evaluated as catalysts for the trichlorosilane mediated asymmetrichydrosilylation of ketimines. bis-Phosphine oxides, hydroxy-phosphine oxides, and biaryl phosphine oxides all demonstrated good catalytic activity, but poor to moderate enantioselectivity. A bis-P-chiral phosphine oxide displayed the highest enantioselectivity of 60%.
已经制备了一系列双官能氧化膦,并评价了其为三氯硅烷介导的酮亚胺的不对称氢化硅烷化的催化剂。双膦氧化物,羟基膦氧化物和联芳基膦氧化物都表现出良好的催化活性,但是对映选择性差至中等。甲双- P -手性膦氧化物显示的60%的最高的对映选择性。
Reduction of Tertiary Phosphine Oxides with DIBAL-H
作者:Carl A. Busacca、Ravinder Raju、Nelu Grinberg、Nizar Haddad、Paul James-Jones、Heewon Lee、Jon C. Lorenz、Anjan Saha、Chris H. Senanayake
DOI:10.1021/jo7024064
日期:2008.2.1
inhibition is tetraisobutyldialuminoxane (TIBAO), which builds up as the reaction proceeds. TIBAO selectively coordinates the TPO starting material, preventing further reduction. Several strategies have been found to circumvent this inhibition and obtain full conversion with this extremely inexpensive reducing agent for the first time. Practical reduction protocols for these critical targets have been developed
详细研究了用二异丁基氢化铝(DIBAL-H)还原叔膦氧化物(TPO)和硫化物。广泛的溶剂筛选表明,受阻脂族醚(例如MTBE)最适合在室温下进行此反应。许多TPO在环境温度下会经历相当大的降低,然后由于抑制作用而失速。31 P和13使用同位素标记的底物进行的13 C NMR研究以及竞争研究表明,这种抑制作用的来源是四异丁基二铝氧烷(TIBAO),随着反应的进行而积累。TIBAO有选择地协调TPO原料,防止进一步减少。已经发现了几种策略来绕开这种抑制作用并首次用这种极其廉价的还原剂获得完全转化。已经为这些关键目标制定了实用的减排方案。
Chemistry of iron complexes. Part 1. Synthesis, characterization, and structures of iron(III) complexes with bis(tertiary phosphine oxides)
and X-ray diffraction data. The cation [Fe(L – L)2Cl2]+ has been assigned a trans-octahedral structure. The nitrate complex of mdpo has a dimeric trigonal bipyramidal cation while the complex of edpo has a cis-octahedral structure. The nitrate complexes of tmdpo and hmdpo also have trigonal bipyramidal structure.