Synthesis of Novel, Highly Reactive Sulfur-containing Species by Taking Advantage of Steric Protection

我们利用2，4，6-三叔丁基苯基（Mes^*）和4-叔丁基-2，6-双[（2，2”，6，6”-四甲基-间三联苯-2 '-基）甲基]苯基（Bmt）等大体积取代基的空间位阻保护作用，合成了两种高活性的有机硫化合物。我们合成的第一种稳定的硫代醛Mes^*CHS与N-溴代或N-氯代丁二酰亚胺反应得到相应的硫代酰卤Mes^*C（=S）X（X=Br，Cl），再与醇、硫醇或胺反应得到硫代酯、二硫代酯或硫代酰胺。BmtLi与CS_2中的硫发生亲硫反应，生成具有卡宾特征的高活性阴离子物种（BmtS）（LiS）C：（1），并与二聚体物种（BmtS）（LiS）C=C（SLi）（SBmt）（2）处于平衡状态。阴离子1在-78℃时稳定，在-30℃时分解为C=S和BmtSLi。这是一种新的生成C=S的方法。

We have synthesized two types of highly reactive organosulfur species by taking advantage of steric protection due to bulky substituents such as 2,4,6-tri-t-butylphenyl (Mes^*) and 4-t-butyl-2,6-bis[(2,2",6,6"-tetrametyl-m-terphenyl-2'-yl)methyl]phenyl(Bmt). Reaction of stable thioaldehyde Mes^*CHS, synthesized by us as the first stable thioaldehyde, with N-bromo- or N-chlorosuccinimide gave the corresponding thioacyl halides Mes^*C(=S)X(X=Br,Cl), which reacted with alcohols, thiols or amines to afford thioesters, dithioesters or thioamides. BmtLi attacked on the sulfur of CS_2 (thiophilic reaction) to produce highly reactive anionic species having carbene character, (BmtS)(LiS)C : (1),which was in equiliprium with dimeric species, (BmtS)(LiS)C=C(SLi)(SBmt) (2).Anionic species 1 and 2 were also formed when HC(=S)(SBmt) was deprotonated with lithium tetramethylpiperidide and quenched with a variety of alkyl halides. Anion 1 was stabe at -78℃ but decomposed into C=S and BmtSLi at -30℃. This represents a novel method for the generation of C=S.