Study on the Conversion of 1,5,3,7-Dichalcogenadiazocines to Cyclic Polychalcogenides

目前的兴趣集中在含硫原子的反应物质上，这些反应物质是由环硫缩醛的断裂产生的。然而，尽管期望通过氧化环收缩得到各种含硫杂环，但对环聚氨基多硫缩醛的氧化研究却很少。特别是，构象柔性的八元氨基缩醛的氧化会引起自发的跨环Ch-Ch相互作用，得到1,5,3,7-二卤代二氮二双环[3.3.0]辛烷型二卤代二卤代，这些二卤代二卤代在亲核试剂对其亚甲基碳的攻击下进一步破碎，得到新的环状二卤代二卤代。我们想描述3,7-二取代的2 H，6H-四氢-1,5,3,7-二氯根二氮杂嗪通过各种氧化剂处理而收缩成1,2,4-二氯根二氮杂烷。用溴处理3,7-二取代的2 H，6H，6H-四氢-1,5,3,7-二噻二氮嘧啶，可得到中等产率的6H-二氢-1,2,3,4,5,7-五噻唑嘧啶，在该反应体系中加入单质硫可提高五噻唑嘧啶的产率。与氯化硫反应，产率较高。另一方面，用不同的氧化剂处理二硒二氮杂嗪和二碲二氮杂嗪，可以得到相应的3h -二氢-1,2,4-硫基偶氮烷，收率较高。反应的中间体应该是具有1,5,3,7-二氯根二氮二双环[3.3.0]辛烷值骨架的二溴或二溴化合物，它们是由两个碳原子跨环相互作用瞬时生成的。综上所述，2H， 6h -四氢-1,5,3,7-二硫代二氮杂嗪经各种氧化剂选择性收缩后，分别得到1,2,3,4,5,7-五噻唑嗪和1,2,4-二硫代二氮杂嗪。

Current interest has been concentrated on the chalcogen atom-containing reactive species generated by the fragmentation of cyclic chalcogenoacetals. However, few studies on the oxidation of cyclic polyaminopolychalcogenoacetals have been achieved in spite of the expectation to give various chalcogen-containing heterocycles through the oxidative ring contraction. Especially, it was expected that oxidation of conformationally flexible eight membered aminochalcogenoacetals would cause spontaneous transannular Ch-Ch interaction to give 1,5,3,7-dichalcogenadiazabicyclo[3.3.0]octane-type dichalcogena dications which would undergo further fragmentation to give novel cyclic dichalcogenidesby the attack of nucleophiles toward the methylene carbons of the dications, In this paper, we would like to describe a novelring contraction of 3,7-Disubstituted 2 H,6H-tetrahydro-1,5,3,7-dichalcogenadiazocines to 1,2,4-dichalcogenazolidines by treating with various oxidizing agents.Treatment of 3,7-disubstituted 2 H,6H-tetrahydro-1,5,3,7-dithiadiazocines with bromine afforded 6H-dihydro-1,2,3,4,5,7-pentathiazocines in moderate yield and the addition of elemental sulfur in this reaction systems resulted in an increase of the yields of pentathiazocines. Reaction with sulfur chloride resulted in a good yield.On the other hand, treatment of diselenadiazocines and ditelluradiazocines with various oxidizing agents afforded the corresponding 3H-dihydro-1,2,4-chalcogenazolidines in good yields. The intermediates of the reactions were supposed to be diselena or ditellura dications possessing 1,5,3,7-dichalcogenadiazabicyclo[3.3.0]octane skeleton generatedtransiently by the transannular interaction of two chalcogen atoms.In conclusion, 2H,6H-tetrahydro-1,5,3,7-dichalcogenadiazocines subjected to selective ring contraction by treating with various oxidizing agents gave 1,2,3,4,5,7-pentathiazocines and 1,2,4-diselena- or ditellurazolidines, respectively.