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.
catalytic amount of cesium carbonate (10 mol%) was found to be capable of effectively catalyzing the insertion of indium powder into alkyl iodides. The thus‐generated alkylindiumreagents could readily undergo palladium‐catalyzed cross‐coupling reactions with a wide variety of arylhalides, showing compatibility to a range of important functional groups.