Iridium(III)-Catalyzed Direct Arylation of C–H Bonds with Diaryliodonium Salts
作者:Pan Gao、Wei Guo、Jingjing Xue、Yue Zhao、Yu Yuan、Yuanzhi Xia、Zhuangzhi Shi
DOI:10.1021/jacs.5b06758
日期:2015.9.30
arylation of complex compounds. Mechanistic studies by density functional theory calculations suggested that the sp(3) C-H activation was realized by a triflate-involved concerted metalation-deprotonation process, and the following oxidation of Ir(III) to Ir(V) is the most favorable when a bistriflimide is contained in the diaryliodonium salt. Calculations indicated that both steps are enabled by initial anion
3. leads to amide products which can be hydrolyzed under mild conditions. The amidation reaction is mild, general and compatible with both primary C−H bonds of tertiary and secondary alcohols, as well as secondary C−H bonds of cyclic secondary alcohols. This method provides an easy access to free 1,2-aminoalcohols after efficient and mild cleavage of the oxime directing group and activated amide.
Described herein is the development of Ir(III)-catalyzed direct C–H amidation using azidoformates as a readily deprotectable amino source. Substrates with unactivated methyl C(sp3)–H and aromatic or olefinic C(sp2)–H bonds were smoothly reacted by the iridium-based catalyst system to provide the corresponding primary alkylamines and anilines upon the subsequent removal of N-protecting groups, such
Mass Spectrometry in Structural and Stereochemical Problems. CCXVII. Electron Impact Promoted Fragmentation of <i>O</i>-Methyl Oximes of some α,β-Unsaturated Ketones and Methyl Substituted Cyclohexanones
作者:Younus M. Sheikh、Raymond J. Liedtke、A. M. Duffield、Carl Djerassi
DOI:10.1139/v72-444
日期:1972.9.1
delineate the modes of mass spectrometric fragmentation of O-methyl oximes of α,β-unsaturated ketones and methyl substituted cyclohexanones. α,β-Unsaturated ketone and 2- and 4-methylcyclohexanone O-methyl oxime ether derivatives fragment upon electron impact in a manner reminiscent of the carbonyl derivatives from which they were prepared. However, several fragmentation sequences characteristic of the O-methyl