Silver-Catalyzed Regioselective Phosphorylation of <i>para</i>-Quinone Methides with P(III)-Nucleophiles
作者:Shipan Xu、Jun Xie、Yu Liu、Weifeng Xu、Ke-Wen Tang、Biquan Xiong、Wai-Yeung Wong
DOI:10.1021/acs.joc.1c01703
日期:2021.11.5
Moreover, a series of corresponding enantiomers can be obtained by employing dialkyl arylphosphonite (ArP(OR)2) as substrates. The control experiments and 31P NMR tracking experiments were also performed to gain insights for the plausible reaction mechanism. This protocol may have significant implications for the formation of C(sp3)–P bonds in Michaelis–Arbuzov-type reactions.
P(III)-亲核试剂 (P(OR) 3 , ArP(OR) 2 , Ar 2 P-OR)银催化对醌甲基化物 ( p -QMs )区域选择性磷酸化的简单有效方法通过 Michaelis-Arbuzov 型反应建立。在温和条件下,广泛的 P(III)-亲核试剂和对-醌甲基化物具有良好的耐受性,从而得到预期的二芳基甲基取代的有机磷化合物,具有良好的产率。此外,以二烷基芳基亚膦酸酯(ArP(OR) 2 )为底物,可以得到一系列相应的对映异构体。对照实验和31还进行了 P NMR 跟踪实验以深入了解可能的反应机制。该协议可能对Michaelis-Arbuzov 型反应中 C( sp 3 )-P 键的形成具有重要意义。
Oxidation of Nitrobenzylic Carbanions with Dimethyldioxirane. New Synthesis of Quinomethanes and Nitrobenzylic Carbinols. First Examples of Methylation of Carbanions with Dimethyldioxirane
The reaction of nitrobenzylic carbanions with dimethyldioxirane (DMD) results in oxidation at the carbanion center or at the nitronate center to give nitrobenzylic carbinols or quinomethanes, respectively. Minor amounts of the methylation products are also formed. Both of these processes were observed for carbanions of (p-nitroaryl)diarylmethanes. The outcome of the oxidation process is very sensitive
Flash photolytic generation and study of<i>p</i>-quinone α-phenylmethide and<i>p</i>-quinone α,α-diphenylmethide in aqueous solution
作者:J. A. Chang、A. J. Kresge、H.-Q. Zhan、Y. Zhu
DOI:10.1002/poc.767
日期:2004.6
p-Quinone α-phenylmethide (7) and p-quinone α,α-diphenylmethide (8) were generated by flashphotolytic dehydration of p-hydroxy-α-phenylbenzyl alcohol (9, R1 = Ph, R2 = H) and p-hydroxy-α,α-diphenylbenzyl alcohol (9, R1 = R2 = Ph) respectively, and rates of their decay were measured in aqueous perchloric acid and sodium hydroxide solutions and also as in acetic acid, biphosphate ion, tris(hydroxym
对苯二酚α-苯甲基(7)和对苯醌α,α-二苯甲基(8)是通过对羟基-α-苯基苯甲醇(9,R 1 = Ph,R 2 = H)的快速光解脱水制得的。对羟基-α,α-二苯基苄醇(9,R 1 = R 2 分别在高氯酸水溶液和氢氧化钠溶液中以及在乙酸,二磷酸根离子,三(羟甲基)甲基铵离子,铵离子和碳酸氢根离子缓冲液中测量其衰减速率。这些数据提供的这些醌甲基化物的水合速率分布图显示了hydro离子和氢氧根离子催化的区域以及“未催化的”水反应,在稀溶液中对于二苯基取代的底物饱和了nium离子的催化,但仅在浓缩状态下有效。碱性较低的单苯基底物的酸性溶液。两种底物也都具有相反的水合氢离子同位素效应(k H + / k D + <1)。这些结果表明,氢醌离子催化的反应是通过醌甲基化物在其羰基氧原子上的快速预平衡质子化,然后确定由水形成的苄型碳正离子的捕获率而发生的。苯基取代会延迟水合速率,还会降低醌甲基
Staudinger, Chemische Berichte, 1908, vol. 41, p. 1359
作者:Staudinger
DOI:——
日期:——
854. Free radicals and radical stability. Part XVI. The properties of triarylmethanols containing p-hydroxyl substituents, and the quinonoidation theory of free radicals