Synthesis of (p-Nitroaryl)diarylmethanes via Vicarious Nucleophilic Substitution of Hydrogen
作者:M. Ma˛kosza、M. Surowiec、S. Voskresensky
DOI:10.1055/s-2000-6411
日期:——
(p-Nitroaryl)diarylmethanes are readily prepared via vicarious nucleophilic substitution of hydrogen in nitroarenes with carbanions of diarylmethyl p-chlorophenyl sulfide. These carbanions are efficient for introduction of diarylmethyl substituents in the para position of nitroarenes via the VNS reaction. The reaction does not proceed ortho to the nitro group due to steric hindrances on the addition step.
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