Cobalt-catalyzed cross-coupling reactions of alkyl halides with aryl Grignard reagents and their application to sequential radical cyclization/cross-coupling reactions
Reactions of alkyl halides with arylmagnesium bromides in the presence of cobalt(II)(diphosphine) complexes are discussed. Treatment of 1-bromooctane with phenylmagnesium bromide with the aid of a catalytic amount of CoCl2(dppp) [DPPP=1,3-bis(diphenylphosphino)propane] yielded octylbenzene in good yield. The reaction mechanism would include single electron transfer from an electron-rich cobalt complex
Copper-Catalyzed Boron-Selective C(sp<sup>2</sup>)–C(sp<sup>3</sup>) Oxidative Cross-Coupling of Arylboronic Acids and Alkyltrifluoroborates Involving a Single-Electron Transmetalation Process
作者:Siyi Ding、Liang Xu、Pengfei Li
DOI:10.1021/acscatal.5b02524
日期:2016.2.5
A rapid and highly selective oxidative cross-coupling reaction between readily available and shelf-stable arylboronic acids and primary or secondary potassium alkyltrifluoroborates was devised and developed, which works under mild conditions using copper(II) acetate as the catalyst and silver oxide as the oxidant. Initial experimental results indicate that a single-electron transmetalation process
A simple protocol for performing chromium-catalyzed highly diastereoselective alkylations of arylmagnesium halides with cyclohexyl iodides at ambient temperature has been developed. Furthermore, this ligand-free CrCl2 enables efficient electrophilic alkenylations of primary, secondary and tetiary alkylmagnesium halides with readily available alkenyl acetates. Moreover, this chemoselective C‒C coupling
benzyl halides and sulfonates imparts unique reactivity at the benzylic carbon atom. Photoredox sp3-sp3 cross-coupling proved ineffective for coupling p-methoxybenzyl chloride (PMBCl), leading to a new strategy for the sp3-sp3 cross-coupling of benzyl halides and sulfonates. This strategy involved LiCl-accelerated synthesis of a Grignard reagent followed by a copper-catalyzed cross-coupling. The conditions
Tandem Intramolecular Carbolithiation-Lithium/Zinc Transmetallation and Applications to Carbon−Carbon Bond-Forming Reactions
作者:Miguel Yus、Rosa Ortiz
DOI:10.1002/ejoc.200400349
日期:2004.9
Lithium/zinc transmetallation with the cyclic organolithium intermediate 3 (prepared by intramolecular carbolithiation of the initially formed organolithium 2) gives the corresponding organozinc intermediate 5. Copper- or palladium-promoted SN2′ reactions between compound 5 and allylic or propargylic halides, as well as arylation, vinylation, benzylation, acylation, and conjugate addition to α,β-unsaturated