Allylic Carbon–Carbon Double Bond Directed Pd-Catalyzed Oxidative <i>ortho</i>-Olefination of Arenes
作者:Parthasarathy Gandeepan、Chien-Hong Cheng
DOI:10.1021/ja300168m
日期:2012.4.4
Pd-catalyzed selective ortho-olefination of arenes assisted by an allylic C-C double bond at room temperature using O-2 as a terminal oxidant is described. A possible mechanism involving the initial coordination of allylic C=C bond to Pd followed by selective o-C-H bond metalation is proposed.
Chemoselective hydroamination of vinyl arenes catalyzed by an NHC-amidate-alkoxide Pd(II) complex and p-TsOH
作者:Richard Giles、Justin O’Neill、Joo Ho Lee、Michael K. Chiu、Kyung Woon Jung
DOI:10.1016/j.tetlet.2013.05.101
日期:2013.7
The hydroamination of various substituted vinyl arenes with benzenesulfonamide was explored using an NHC-amidate-alkoxide palladium catalyst in conjunction with p-TsOH. Utilizing halide-substituted and electron-rich vinyl arenes, this methodology selectively furnished the cross-coupled hydroamination products in moderate to excellent yields in a Markovnikov fashion while greatly reducing undesired acid-catalyzed homocoupling of the vinyl arenes. Electron-rich vinyl arenes typically required milder conditions than electron-poor ones. While most effective for para-substituted substrates, the catalyst system also furnished the desired products from ortho- and meta-substituted vinyl arenes with high chemoselectivities. (C) 2013 Elsevier Ltd. All rights reserved.