The direct insertion of indium powder into alkyl iodides was found to be efficiently catalyzed by a catalytic amount of cobalt(II) bromide (10 mol%). Upon subjection of the thus-formed alkylindium compounds to palladium-catalyzed cross-coupling reactions with a wide range of arylhalides, a series of cross-coupled products could be obtained in moderate to good yields with the tolerance to many important
means of an iodine-catalyzed direct indium insertion into alkyl iodide in THF is reported. The thus-generated alkyl indium reagents effectively underwent Pd-catalyzed cross-couplingreactions with various aryl halides, exhibiting good compatibility to a variety of sensitive functional groups. By replacing THF with DMA and using 0.75 equiv of iodine, less reactive alkyl bromide could be used as substrate
Direct Synthesis of Water-Tolerant Alkyl Indium Reagents and Their Application in Palladium-Catalyzed Couplings with Aryl Halides
作者:Zhi-Liang Shen、Kelvin Kau Kiat Goh、Yong-Sheng Yang、Yin-Chang Lai、Colin Hong An Wong、Hao-Lun Cheong、Teck-Peng Loh
DOI:10.1002/anie.201005798
日期:2011.1.10
A direct result: Alkylindiumreagents are synthesized by the insertion of indium into alkylhalide mediated by CuCl. The synthetic utility of these reagents is demonstrated by their palladium‐catalyzed coupling with arylhalides (see scheme). The reagents are compatible with various functional groups, and this makes the protocol generally useful in organic synthesis. DMA=N,N‐dimethylacetamide, TB
effectively underwent palladium-catalyzed cross-coupling reactions with a myriad of aryl halides in aqueous media, leading to the cross-coupled products in modest to high yields. The mildness of the formed alkylorganometallics allowed the tolerance to various important functional groups incorporated in both substrates of alkyl iodides and aryl halides.
A Cobalt-Catalyzed Alkene Hydroboration with Pinacolborane
作者:Lei Zhang、Ziqing Zuo、Xuebing Leng、Zheng Huang
DOI:10.1002/anie.201310096
日期:2014.3.3
efficient cobalt catalyst for the hydroboration of both vinylarenes and aliphatic α‐olefins with pinacolborane is described, providing the anti‐Markovnikov products with excellent regio‐ and chemoselectivity, broad functional‐group tolerance, and high turnover numbers (up to 19 800). The alkenehydroboration route is further extended to a two‐step, one‐pot hydroboration and cross‐coupling of alkylboronates