已经测量了从广泛的路易斯碱硼烷加合物中置换 BH 3的奎宁环动力学。这些速率的参数化使得能够开发出离核量表 (NF B ),以量化和预测一系列其他路易斯碱基的离去基团能力。在多个系列 R' 3– n R n X (X = P, N; R' = 芳基, 烷基) 中观察到的可加性允许制定相关的取代基参数 ( n f PB , n f AB ),提供了一种方法计算N F B一系列路易斯碱基的值远远超出了实验得出的值。通过取代基参数n f PB与一系列烷基和芳基 MIDA 硼酸盐在中性条件下的水解速率的相关性,探索了核离性参数的效用。这允许鉴定具有接近反应中心的杂原子的 MIDA 硼酸盐,显示出不寻常的动力学不稳定性或水解稳定性。
Activation of sodium borohydride <i>via</i> carbonyl reduction for the synthesis of amine- and phosphine-boranes
作者:P. Veeraraghavan Ramachandran、Henry J. Hamann、Randy Lin
DOI:10.1039/d1dt03495b
日期:——
carbonyl reduction by sodiumborohydride is described. Unlike the prior bicarbonate-mediated protocol, which proceeds via a salt metathesis reaction, the carbon dioxide-mediated synthesis proceeds via reduction to a monoformatoborohydride intermediate. This has been verified by spectroscopic analysis, and by using aldehydes and ketones as the carbonyl source for the activation of sodiumborohydride. This
Organocatalyzed Reduction of Tertiary Phosphine Oxides
作者:Marie-Luis Schirmer、Stefan Jopp、Jens Holz、Anke Spannenberg、Thomas Werner
DOI:10.1002/adsc.201500762
日期:2016.1.7
A novel selective catalytic reduction method of tertiaryphosphineoxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1–5 mol% even at low temperature (70 °C). Under the optimized conditions various phosphineoxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%