Inherent Reactivity of Spiro‐Activated Electrophilic Cyclopropanes
作者:Patrick M. Jüstel、Alexandra Stan、Cedric D. Pignot、Armin R. Ofial
DOI:10.1002/chem.202103027
日期:2021.11.17
Ring, ring! The reactivity of spiro-activated electrophilic cyclopropanes was studied by following the kinetics of their SN2-type ring-opening reactions with thiophenolate ions in DMSO at 20 °C. The experimentally determined second-order rate constants (k2) correlated linearly with Mayr nucleophilicities N, basicities (pKaH), and Hammett substituent constants of the thiophenolates, but parabolic Hammett
响铃,响铃!通过跟踪螺环活化的亲电环丙烷在 20 °C 的 DMSO 中与苯硫酚离子的 S N 2 型开环反应的动力学,研究了螺环活化的亲电环丙烷的反应性。实验确定的二阶速率常数 ( k 2 ) 与迈尔亲核性N 、碱度 (p K aH ) 和苯硫酚盐的哈米特取代基常数线性相关,但抛物线哈米特图揭示了对转变稳定性的不同亲电子依赖性影响州。
Kinetics of α-chlorination of sulphoxides by N-chlorobenzotriazole
作者:Dario Landini、Angela Maia
DOI:10.1039/p29750000218
日期:——
The α-chlorination of aryl methyl and aryl isopropyl sulphoxides with N-chlorobenzotriazole in acetonitrile in the presence of pyridine follows second-order kinetics. The reaction is favoured by electron-donating groups and is subject to a noticeable kinetic isotope effect (KH/KD). On the basis of the kinetic data a common reaction mechanism is proposed for the two series of sulphoxides, involving
在吡啶存在下,在乙腈中用N-氯苯并三唑进行芳基甲基和芳基异丙基亚砜的α-氯化反应遵循二级动力学。该反应受供电子基团的促进,并且受到明显的动力学同位素效应(K H / K D)。根据动力学数据,提出了两个亚砜系列的通用反应机理,其中涉及形成中间体的氯-氧磺酸盐,在速率确定步骤中,该盐在碱的作用下分解成α-氯亚砜。