A simple approach for constructing a new boron–carbon bond by direct insertion into the B–H bond of amine– and phosphine–borane complexes is described. The outcome of this reaction was studied according to the substituents and the experimental conditions. A preliminary investigation of the reactivity of some insertion products as well as their anti-proliferative activities is also reported.
General and Efficient One-Pot Synthesis of Tertiary Phosphane–Borane Complexes Containing Different Alkyl Groups and In Situ Facile Recycling of the Phosphorus Donor Reagent
Tertiary symmetric and asymmetric phosphane–borane complexes containing different alkyl groups, including bulky groups, can be obtained by the addition of different Grignard reagents to benzothiadiphosphole 1 followed by direct complexation with BH3·THF. Treatment of the resulting mixture with PCl3 led to the reformation of the starting reagent 1, which was recovered from the reaction mixture by simple
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。
A Catalytic Method for the Reduction of Secondary and Tertiary Phosphine Oxides
TMDS has been found to be an efficient hydride source for the reduction of tertiary and secondary phosphineoxides using a catalytic amount of Ti(O I-Pr) 4 . All classes of tertiary phosphineoxides, such as triaryl, trialkyl, and diphosphine, were effectively reduced.
[figure: see text] Various phosphineoxides are efficiently reduced by the use of a methylation reagent and lithium aluminum hydride. Optically active P-chirogenic phosphineoxides are also reduced with inversion of configuration at phosphorus atom by treatment with methyl triflate, followed by reaction with LiAlH4.