Substituent effects at the origin of a free-radical 1,2-aryl migration and in the related disproportionation reaction of 10-hydro-9-p-X-phenyl-9-phenanthryl radicals
cross‐coupling of aryl tosylates with alkyl and aryl Grignardreagents is reported. The catalytic system uses CoF3 and NHCs (NHC=N‐heterocyclic carbene) as ancillary ligands. The reaction proceeds via highly selective C−O bond functionalization, leading to the corresponding products in up to 98 % yield. The employment of alkylGrignardreagents allows to achieve a rare C(sp2)−C(sp3) cross‐coupling of
Suzuki‐Miyaura coupling of haloarenes is the most widely used protocol for the synthesis of biphenyls. Organosulfur compounds are promising electrophiles since they are abundant in nature and versatile in organic synthesis. We report here the desulfinylative Suzuki‐Miyaura coupling of aryl sulfoxides with phenylboronic acids using bench‐stable nickel/5‐(2,4,6‐triisopropylphenyl)imidazolylidene[1,5‐a]pyridines
卤代芳烃的Suzuki-Miyaura偶联是联苯合成中使用最广泛的方案。有机硫化合物是有前途的亲电子试剂,因为它们性质丰富且有机合成用途广泛。我们在此报告使用稳定的镍/ 5-(2,4,6-三异丙基苯基)咪唑基亚甲基[1,5- a ]吡啶作为催化剂将芳基亚砜与苯基硼酸的脱亚磺酰基铃木-宫浦偶合。配体易于从常见的商业化学品制备。该方法适用于对称和不对称的芳基亚砜,并且以高达94%的收率获得了一系列带有各种官能团的联苯。
Palladium-catalyzed Direct C–H Bond Arylation of Simple Arenes with Aryltrimethylsilanes
作者:Kenji Funaki、Hiroshi Kawai、Tetsuo Sato、Shuichi Oi
DOI:10.1246/cl.2011.1050
日期:2011.9.5
Direct C–H bond arylation of arenes with aryltrimethylsilanes catalyzed by PdCl2 in the presence of CuCl2 as an oxidant has been developed. In addition to the role as the oxidant, CuCl2 is found to be necessary for the selective cross-coupling reaction.
Phenanthrene Synthesis by Eosin Y-Catalyzed, Visible Light- Induced [4+2] Benzannulation of Biaryldiazonium Salts with Alkynes
作者:Tiebo Xiao、Xichang Dong、Yanchi Tang、Lei Zhou
DOI:10.1002/adsc.201200569
日期:2012.11.26
A metal-free, visible light-induced [4+2] benzannulation of biaryldiazonium salts with alkynes was developed. With eosin Y as photoredox catalyst, a variety of 9-substituted or 9,10-disubstitutedphenanthrenes were obtained via a cascade radical addition and cyclization sequence.
Gold-catalyzed efficient tandem assembly of terminal alkynes and arynes: synthesis of alkynylated biphenyl derivatives
作者:Chunsong Xie、Yuhong Zhang、Yuzhu Yang
DOI:10.1039/b806821f
日期:——
Gold catalysts have been found to catalyze the tandem assembly of arynes and terminal alkynes efficiently in the presence of CuI under mild reaction conditions to provide useful alkynylated biphenyl derivatives.