A robust and sustainable C(sp2)–C(sp3) cross-electrophile coupling was developed via nickel/copper synergistic catalysis under micellar conditions.
通过镍/铜协同催化在胶束条件下开发了稳健且可持续的C(sp²)–C(sp³)交叉电愿偶联。
Zn-Mediated, Pd-Catalyzed Cross-Couplings in Water at Room Temperature <i>Without</i> Prior Formation of Organozinc Reagents
作者:Arkady Krasovskiy、Christophe Duplais、Bruce H. Lipshutz
DOI:10.1021/ja906803t
日期:2009.11.4
Mix in water, stir. That is all that is required in this new approach to sp(3)-sp(2) cross-couplings between an alkyl iodide and an aryl bromide, both potentially bearing functionality. They react under catalysis by Pd(0) in the presence of zinc powder, aided by a nonionic amphiphile, to give the alkylated aromatic. No organic solvents and no heating; just add water.
In this study, nickel-catalyzedcoupling reactions between arylhalides and tert-alkyl Grignardreagents were developed. Our original bicyclic NHC ligands reduced the formation of isomerized products, and we found that NMP as a co-solvent suppressed the reduction process. Under the optimal conditions we developed, the catalyst loading was lowered to 0.5 mol %, and catalyst loading using ortho-substituted
Palladium-Catalyzed Conversion of Aryl and Vinyl Triflates to Bromides and Chlorides
作者:Xiaoqiang Shen、Alan M. Hyde、Stephen L. Buchwald
DOI:10.1021/ja107481a
日期:2010.10.13
The palladium-catalyzed conversion of aryl and vinyltriflates to aryl and vinyl halides (bromides and chlorides) has been developed using dialkylbiaryl phosphine ligands. A variety of aryl, heteroaryl, and vinyl halides can be prepared via this method in good to excellent yields.
Abstract A ligand-free nickel-catalyzed Kumada cross-coupling of aryl bromides and tert-butyl Grignardreagents led to the formation of a series of tert-butyl aryls in moderate to good yields, excellent tBu/iBu ratios, and good functional group compatibility. A radical coupling process is indicated and a mechanism with a Ni(I)-Ni(III) catalytic cycle is proposed.