Thiocarbonyl Ylide Intermediates Generated by Deprotonation of 2-Phenacylthio- and 2-(<i>p</i>-Bromophenacylthio)-1,3-dithiolylium and 2-(<i>p</i>-Bromophenacylthio)-1,3-dithiolanylium Bromides
作者:Juzo Nakayama、Toshiro Takemasa、Masamatsu Hoshino
DOI:10.1246/bcsj.53.2281
日期:1980.8
2-(p-Bromophenacylthio)-1,3-dithiolylium bromide, when treated with triethylamine, gave 2-(p-bromophenacylidene)-1,3-dithiole (17%) and bis[(p-bromobenzoyl)(1,3-dithiol-2-ylidene)methyl] disulfide (72%). Treatment of 2-phenacylthio-1,3-dithiolylium bromide with triethylamine also gave similar results. On the other hand, 2-(p-bromophenacylthio)-1,3-dithiolanylium bromide yielded 1-(p-bromophenyl)-2-(1,3-dithiolan-2-yl)-2-thioxoethanone (12%) in addition to 2-(p-bromophenacylidene)-1,3-dithiolane (49%) contrary to the reported results. These results can best be rationalized by 1,3-cyclization of thiocarbonyl ylide intermediates to the valence tautomeric episulfides.
2-(对溴苯乙酰硫)-1,3-二硫铵溴化物在与三乙胺反应后,得到了2-(对溴苯乙酰基烯)-1,3-二硫烯(17%)和双[(对溴苯酰)(1,3-二硫烯-2-基)甲基]二硫化物(72%)。将2-苯乙酰硫-1,3-二硫铵溴化物与三乙胺反应也得到了类似的结果。另一方面,2-(对溴苯乙酰硫)-1,3-二硫烯铵溴化物除了生成1-(对溴苯基)-2-(1,3-二硫烯-2-基)-2-硫烯乙酮(12%),还得到了2-(对溴苯乙酰基烯)-1,3-二硫烯(49%),这与之前的报道结果相反。这些结果可以通过硫羰基耦合中间体的1,3-环化反应,转化为价基式肟化物来最好地解释。