Efficient Aqueous-Phase Heck Reaction Catalyzed by a Robust Hydrophilic Pyridine-Bridged Bisbenzimidazolylidene-Palladium Pincer Complex
作者:Tao Tu、Zhixun Wang、Xike Feng、Weiwei Fang
DOI:10.1055/s-0030-1259723
日期:2011.4
The first efficient example of NHC-palladium pincer complexcatalyzed aqueous Heck reaction with extremely low catalyst loadingwas realized without obvious hydrolysis of products by using a robusthydrophilic pyridine-bridged bisbenzimidazolylidene-palladiumcomplex as a molecular catalyst, which tolerated various electronicproperties of substituted functional groups in arenes.
site-selectivity in arene functionalization that is complementary to the site-selectivity from electrophilic aromatic substitution reactions has been a long-standing quest in organic synthesis. Palladium/norbornene cooperative catalysis potentially offers a unique approach to this problem, but its use has been hampered by the ortho constraint, which is the requirement of an ortho substituent for mono ortho functionalization
Borane catalyzed transesterification of <i>tert</i>-butyl esters using α-aryl α-diazoesters
作者:Maying Yan、Lei Xiao、Jiangkun Xiong、Lvnan Jin、Douglas W. Stephan、Jing Guo
DOI:10.1039/d3ob01548c
日期:——
The B(C6F5)3-catalyzed transesterification of a series of 3-alkenyl-oxindoles and other unsaturated tert-butyl esters with aryl-diazo esters is reported. This protocol is facile and generally high yielding proceeding under mild conditions and is remarkably chemoselective leaving the CC bonds intact.
报道了一系列3-烯基-羟吲哚和其他不饱和叔丁基酯与芳基重氮酯的B(C 6 F 5 ) 3催化酯交换反应。该方案在温和条件下操作简便且通常产率高,并且具有显着的化学选择性,使 C C 键完好无损。
Palladium-catalyzed Heck coupling of arylhydrazines via C–NHNH<sub>2</sub>bond activation
作者:Jin-Biao Liu、Fu-Jiao Chen、Na Liu、Jiang Hu
DOI:10.1039/c5ra05131b
日期:——
A novel palladium-catalyzed Heck coupling reaction of arylhydrazines with olefins is described, which affords various styrenes with high efficiency. This transformation proceeds through a C–NHNH2bond activation under mild conditions.
[2.2]Paracyclophane-based carbene–copper catalyst tuned by transannular electronic effects for asymmetric boration
作者:Jianqiang Chen、Wenzeng Duan、Zhen Chen、Manyuan Ma、Chun Song、Yudao Ma
DOI:10.1039/c6ra14404g
日期:——
of planar chiral carbene–copper complexes based on the [2.2]paracyclophane backbone with a pseudo-ortho substitution pattern have been synthesized and applied to asymmetric β-boration of α,β-unsaturatedesters. As a result, transannular electronic effects of the substituent of the chiralcatalyst have significant influence on the catalytic performance. A variety of chiral β-hydroxyl esters were obtained