Visible-Light-Driven Difluoromethylation of Isocyanides with <i>S</i>-(Difluoromethyl)diarylsulfonium Salt: Access to a Wide Variety of Difluoromethylated Phenanthridines and Isoquinolines
作者:Wen-Bing Qin、Wei Xiong、Xin Li、Jia-Yi Chen、Li-Ting Lin、Henry N. C. Wong、Guo-Kai Liu
DOI:10.1021/acs.joc.0c00816
日期:2020.8.21
variety of difluoromethylated phenanthridines and isoquinolines is herein described. Electrophilic S-(difluoromethyl)diarylsulfonium salt proved to be a good difluoromethyl radical precursor under photoredox catalysis. A broad range of isocyanides were tolerated to furnish the corresponding difluoromethylated phenanthridines, isoquinolines, furo[3,2-c]pyridine, and pyrido[3,4-b]indole in moderate to
本文描述了一种有效的方法,将可见光驱动的异氰酸酯基自由基二氟甲基化处理,以使用各种二氟甲基化菲啶和异喹啉。在光氧化还原催化下,亲电S-(二氟甲基)二芳基ulf盐被证明是良好的二氟甲基自由基前体。在温和的条件下,宽范围的异氰化物可以中等至极好的收率提供相应的二氟甲基化菲啶,异喹啉,呋喃[3,2- c ]吡啶和吡啶并[3,4- b ]吲哚。还提出了一个合理的机制。
Transition-Metal-Free Direct Arylation of Anilines
作者:Tracey Pirali、Fengzhi Zhang、Anna H. Miller、Jenna L. Head、Donald McAusland、Michael F. Greaney
DOI:10.1002/anie.201106150
日期:2012.1.23
Aryne arylation: A new method of directarylation is reported for aniline substrates. The reaction uses benzyne to synthesize a variety of aminobiaryls under mild conditions (see scheme), requiring no stoichiometric metalation or transition‐metal catalysis. An ene mechanism is implicated, and conveys excellent functional group tolerance relative to metal‐mediated processes.
The first example of the palladium-catalyzed primary amine-directed C(sp2)–H alkynylation of biaryl-2-amines has been developed by using (bromoethynyl)triisopropylsilane as an alkynylating reagent. This protocol exhibits a broad substrate scope, excellent regioselectivity and gram-scale synthesis. Significantly, the versatility of this straightforward method was further demonstrated by controlled mono-
Aryl to Aryl Palladium Migration in the Heck and Suzuki Coupling of <i>o</i>-Halobiaryls
作者:Marino A. Campo、Haiming Zhang、Tuanli Yao、Abdellatif Ibdah、Ryan D. McCulla、Qinhua Huang、Jian Zhao、William S. Jenks、Richard C. Larock
DOI:10.1021/ja069238z
日期:2007.5.1
A novel 1,4-palladium migration between the o- and o'-positions of biaryls has been observed in organopalladium intermediates derived from o-halobiaryls. The organopalladium intermediates generated by this migration have been trapped either by a Heck reaction employing ethyl acrylate or by Suzuki cross-coupling using arylboronic acids. This palladium migration can be activated or deactivated by choosing the appropriate reaction conditions. Chemical and computational evidence supports the presence of an equilibrium that correlates with the C-H acidity of the available arene positions.