β-Functionalised radicals in organic synthesis: 2-acyloxyalkyl radicals from 2-acyloxyalkyl iodides by the tin route
作者:Francisco Foubelo、Francisco Lloret、Miguel Yus
DOI:10.1016/s0040-4020(01)90423-5
日期:1994.4
The reaction of iodoesters 1a-c with electrophilic olefins 2a-d and in situ generated tributyltin hydride (from a substoichiometric amount of tributyltin chloride and an excess of sodium borohydride) in the presence of a catalytic amount of AIBN in ethanol at 0 to 20°C yields the expected coupling products 3aa-3cd. Products 4 resulting from an iodine/hydrogen exchange are also obtained as by-products
在乙醇中催化量的AIBN存在下,在0至20°C的条件下,碘酸酯1a-c与亲电烯烃2a-d反应并原位生成氢化三丁基锡(由亚化学计量的氯化三丁基锡和过量的硼氢化钠) C产生预期的耦合积3aa-3cd。由碘/氢交换得到的产物4也作为副产物以可变的量获得。研究了偶联反应的立体化学:从反式-2-碘代环己基乙酸酯(1d)和丙烯酸甲酯(2a)开始,相应顺式/反式的1/3混合物获得非对映异构体。该结果表明相应的自由基偶联不是立体特异性的。