Palladium-Catalyzed Decarboxylative Ortho-Ethoxycarbonylation of O-Methyl Ketoximes and 2-Arylpyridines with Potassium Oxalate Monoester
摘要:
A novel method for introducing an ester group via palladium-catalyzed ligand-directed C-H activation has been explored. The ortho-ethoxycarbonylation of O-methyl ketoximes proceeded smoothly with the nontoxic and easily handled reagent potassium oxalate monoester, affording the desired products in moderate to good yields. Furthermore, pyridine could also be employed as a directing group to obtain similar results in this transformation.
Palladium-Catalyzed Oxidative Ethoxycarbonylation of Aromatic C−H Bond with Diethyl Azodicarboxylate
作者:Wing-Yiu Yu、Wing Nga Sit、Kin-Man Lai、Zhongyuan Zhou、Albert S. C. Chan
DOI:10.1021/ja710555g
日期:2008.3.1
(DEAD) together with Oxone or K2S2O8. Substrates such as 2-arylpyridines, pyrrolidinone, acetylindoline, quinoline, and oximes were ethoxycarbonylated with excellent chemo- and regioselectivities. The catalytic reaction is probably initiated by chelation-assisted cyclopalladation of the ortho-C−H bond. Preliminary studies suggested that reactive ethoxyacyl radicals generated from thermal decomposition
A palladium-catalyzed ortho-directed alkylation of O-methyl ketoximes that proceeds through a regioselective ring-opening reaction of epoxides has been demonstrated. This C(sp2)–H activation/alkylation protocol was carried out in pivalic acid/1,1,1,3,3,3-hexafluoro-2-propanol (PivOH/HFIP, 2:8) as the solvent and was applied to various O-methyl ketoximes that contain either electron-donating or electron-withdrawing
Rh(III)- and Ir(III)-Catalyzed C–H Alkynylation of Arenes under Chelation Assistance
作者:Fang Xie、Zisong Qi、Songjie Yu、Xingwei Li
DOI:10.1021/ja501910e
日期:2014.3.26
Rh(III)- and Ir(III)-catalyzed, chelation-assisted C-H alkynylation of a broad scope of (hetero)arenes has been developed using hypervalent iodine-alkyne reagents. Heterocycles, N-methoxy imines, azomethine imines, secondary carboxamides, azo compounds, N-nitrosoamines, and nitrones are viable directing groups to entail ortho C-H alkynylation. The reaction proceeded under mild conditions and with controllable
Ruthenium(II)-Catalyzed α-Fluoroalkenylation of Oxime Ethers with <i>gem</i>-Difluorostyrenes <i>via</i> C–H Activation and C–F Cleavage
作者:Lili Zhang、Kezuan Deng、Gaorong Wu、Jinyue Yang、Shibiao Tang、Xiaopan Fu、Chengcai Xia、Yafei Ji
DOI:10.1021/acs.joc.0c01842
日期:2020.10.2
A novel route for ruthenium(II)-catalyzed α-fluoroalkenylation of oxime ethers with gem-difluorostyrenes via C–Hactivation and C–F cleavage has been developed for the first time. Notably, the alkenyl units of products exhibit exclusive Z-configuration. This reaction features a broad substrate scope and good functional group tolerance. A plausible reaction mechanism is confirmed by an available cycloruthenated
Palladium-catalyzed oxime ether directed regioselective C-H alkoxylation of arenes
作者:Liang Pan、Liang Wang、Qun Chen、Mingyang He
DOI:10.1080/00397911.2016.1242749
日期:2016.12.16
ABSTRACT A palladium-catalyzed highly regioselective ortho-C(sp2)-H alkoxylation of oxime ethers with PhI(OAc)2 as the oxidant and alcohols as the alkoxylation reagents has been developed. Mono-alkoxylated and acetoxylated products could be selectively obtained via tuning the reaction conditions. A series of oxime ethers were tolerated, affording the corresponding products in moderate to good yields