The ozonation of the O-methyloximes has been investigated. Besides the corresponding ketones, ketone diperoxides, and N-methoxyamides were produced. The stereochemistry of the ketone diperoxides was studied by the NMR technique.
Palladium-catalyzed arene C(sp2)–H acetoxylation has emerged as a powerful tool to construct a carbon–oxygen (C–O) bond. However, the requirement of stoichiometric chemical oxidants for this transformation possesses a significant disadvantage. To solve this fundamental problem, we now report an anodic oxidation strategy to achieve arene C(sp2)–H acetoxylation.
A highly para‐selective CAr−H difluoromethylation of ketoxime ethers under ruthenium catalysis has been developed. A wide variety of ketoxime ethers are compatible with the reaction, which leads to the corresponding para‐difluoromethylated products in moderate to good yield. A mechanistic study clearly showed that chelation‐assisted cycloruthenation is the key factor in the para selectivity of the
已经开发了在钌催化下酮肟醚的高度对位选择性C Ar -H二氟甲基化。各种各样的酮肟醚均可与该反应相容,从而以中等至良好的产率产生相应的对二氟甲基化产物。一项机理研究清楚地表明,螯合辅助的环化钌是影响酮肟醚二氟甲基化对位选择性的关键因素。使用密度泛函理论来获得对位选择性的理论理解。#
OrthoC H amidations enabled by a recyclable manganese-ionic liquid catalytic system
作者:Xianqiang Kong、Bo Xu
DOI:10.1016/j.tetlet.2019.151521
日期:2020.2
We described an environmentally benign, recyclable base metal catalyst system (MnBr(CO)(5)/[Hmim] OAc) for ortho-C-H amidation. The readily available dioxazolones was used as the amidation agents. A broad substrate scope and high functional group tolerance were observed. The catalyst system (MnBr(CO)(5)/[Hmim]OAc) could be easily reused by simple phase separations: (C) 2019 Elsevier Ltd. All rights reserved.