摘要
本文研究了在四氟硼酸银存在下,硫醚与碘甲烷室温下发生碳硫键选择性断裂反应。研究结果表明:只有当二苄基硫醚的苯环对位连有强的供电子基团甲氧基时,方可发生碳硫键的断裂。提出了一个离子型反应机理且碳硫键的断裂分三步完成。首先,硫醚与甲基化试剂反应生成甲基锍盐;继而,此锍离子离解成由苄基碳正离子和硫醚组成的离子—偶极集合物;最后,甲基化试剂再进攻集合物中的硫醚,从而导致碳硫键的断裂。
The reaction of various dibenzylsulfides with excess methyl iodide in the presence of excess silver tetrafluoroborate at room temperature and the carbon - sulfur bond selective cleavage reac-tion in some case were studied. The results showed that only the benzyl group with p - methoxy sub-stituent could undergo bond cleavage. The carbon - sulfur bond cleavage process might consist of three steps.The first, sulfide reacts with methylation agent to form methylsulfonium salt and the second, sulfonium ion undergoes dissociation to form an ion - dipole assemblage consisting of benzyl carbocation and sulfide. Finally, methylating agent attacks sulfide in assemblage to cleavage carbon - sulfur bond.
出处
《有机化学》
SCIE
CAS
CSCD
北大核心
1996年第6期507-513,共7页
Chinese Journal of Organic Chemistry
基金
煤炭系统留学回国人员科技基金
关键词
硫醚
碳硫键
断裂
选择性
Sulfides, selective carbon - sulfur bond cleavage, mechanism
