FREE-RADICAL ADDITION OF ALKANETHIOLS TO ALKYNES - REARRANGEMENTS OF THE INTERMEDIATE BETA-THIOVINYL RADICALS
FREE-RADICAL ADDITION OF ALKANETHIOLS TO ALKYNES - REARRANGEMENTS OF THE INTERMEDIATE BETA-THIOVINYL RADICALS
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DOI：
10.1021/jo00089a030
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发表时间：
1994-05-20
影响因子：
3.6
通讯作者：
SPAGNOLO, P
中科院分区：
文献类型：
--
作者：
BENATI, L;CAPELLA, L;SPAGNOLO, P
通过烷硫醇（包括苯乙基硫醇、烯丙基硫醇和苄基硫醇）与单取代乙炔在苯中在90 ℃下的自由基反应，已经产生了多种2-巯基取代的乙烯基。8-（苄硫基）乙烯基自由基6容易重排成（乙烯基硫基）甲基自由基7通过苯基从硫甲基到乙烯基碳的新颖的1，4-迁移; 2-（苯乙硫基）乙烯基自由基12经历内部1，5-氢转移以形成β-硫代取代的苄基自由基13，该苄基自由基13又经历乙烯基硫基自由基18的快速β-消除;和2-（烯丙基硫基）乙烯基自由基20进行动力学优选的5-外环化，得到伯自由基26，其可以容易地重排为更稳定的扩环自由基25。
A variety of 2-mercapto-substituted vinyl radicals have been produced through the free-radical reaction of alkanethiols (including phenethyl, allyl, and benzyl mercaptans) with monosubstituted acetylenes in benzene at 90 degrees C. The 8-(benzylthio)vinyl radicals 6 readily rearranged to (vinylthio)methyl radicals 7 via a novel 1,4-migration of the phenyl group from thiomethyl to vinyl carbon; 2- (phenethylthio)vinyl radicals 12 underwent internal 1,5-hydrogen transfer to form beta-thio-substituted benzyl radicals 13 which in turn suffered fast beta-elimination of vinylthio radicals 18; and 2-(allylthio)vinyl radical 20 underwent kinetically preferred 5-exo cyclization to give the primary radical 26 which could easily rearrange to the more stable ring-expanded radical 25.