Iodine atom transfer addition reaction of 1-iodoalkyl phosphonates to alkenes in the presence of α,α′-azoisobutyronitrile (AIBN): mechanistic aspects
作者:Piotr Bałczewski、Marian Mikołajczyk
DOI:10.1039/b005882n
日期:——
this work were to elucidate the mechanistic pathway of the title reaction, which constitutes the first example of a radical iodine atom transfer addition reaction of non-fluorine-containing phosphonates, and to determine whether 2-iodo-2-methylpropionitrile, 8, can serve as a competing iodine donor with the starting diethyl 1-iodoalkyl phosphonates, 1a,b. The title reaction was found to proceed with AIBN
这项工作的目的是阐明标题反应的机理途径,该机理构成了不含氟的膦酸酯的自由基碘原子转移加成反应的第一个实例,并确定2-碘-2-甲基丙腈是否8可以与1-碘烷基膦酸二乙酯1a,b一起作为竞争的碘供体。发现标题反应是使用AIBN作为唯一的自由基引发剂进行的,不需要有毒的锡试剂作为助引发剂,并生成3-碘烷基膦酸二乙酯3a – e(繁殖步骤的最终产物,分离出的产率为59–95% ),丁二酸琥珀酯,9,甲基膦酸二乙酯4,亚乙基双膦酸四乙酯 5(所有终止产物,产率0-10%)。使用TEMPO作为自由基陷阱证明了该反应的自由基特性。与AIBN和碘独立合成的8(引发步骤的中间体)在添加到反应混合物中时完全抑制了反应,表明它在转移阶段不作为碘供体,而是作为抑制剂。