Tri(hetero)substituted Carbonium Ions. VIII. The Hydride Reduction of Cyclic and Open-chain Dithiocarbamidium Salts
作者:Kazuhisa Hiratani、Takeshi Nakai、Makoto Okawara
DOI:10.1246/bcsj.46.3872
日期:1973.12
This provides a practical method for the synthesis of formamide thioacetals. The RDB reduction of 1d at higher temperature, however, yielded abnormal products, thiazolin-2-thione (3) and thiazolidine (4) instead of the formamide thioacetal (2d). The mechanism for the formation of 3 and 4 has been discussed in terms of the ambident character of the cation (1d). Pyrolytic reactions of the thioacetals
对以下五种稳定的 N,S,S-三(杂)取代碳正离子的氢化物还原进行了研究:N,N,S,S'-四甲基二硫代氨基鎓离子 (1a)、2-二甲氨基-1,3- dithiolanylium 离子 (1b)、2-dimethylamino-1,3-dithianylium 离子 (1c)、2-methylthio-3-methyl-4,5-dihydrothiazolium 离子 (1d) 和 2,3,5,6-tetrahydrothiazolo[2 ,3-b] 噻唑鎓离子 (1e)。发现二氢双(甲氧基乙氧基)铝酸钠(RDB)是合适的还原剂。在-5°C 下碳正离子的 RDB 还原以中等产率得到相应的甲酰胺硫缩醛 (2)。这为合成甲酰胺硫缩醛提供了一种实用的方法。然而,在较高温度下还原 1d 的 RDB 会产生异常产物,噻唑啉-2-硫酮 (3) 和噻唑烷 (4),而不是甲酰胺硫缩醛 (2d)。已经根据阳离子的环境特性