Stereoselective hydrogen transfer reactions of vinyl radicals: Cyclization of alkynyl iodides by Unimolecular Chain Transfer from silicon hydrides
作者:Angeles Martinez-Grau、Dennis P. Curran
DOI:10.1016/s0040-4020(97)00257-3
日期:1997.4
hexynyl and heptynyl iodides proceeds stereoselectively to give either E- or Z-exocyclic double bonds depending on the type of precursor and radical chain used. In UniMolecular Chain Transfer (UMCT) reactions, the intramolecular abstraction of hydrogen by the intermediate vinyl radical leads exclusively to the E-isomer while the traditional tin hydride method usually provides the Z-isomer with good
取决于所用的前体和自由基链的类型,几种取代的己炔基碘和庚炔基碘化物的环化立体选择性地进行,以得到E-或Z-环外双键。在单分子链转移(UMCT)反应中,中间乙烯基基团对氢的分子内提取仅导致E-异构体,而传统的氢化锡方法通常为Z-异构体提供良好的选择性。