Direct Synthesis of Thiiranes from Alkenes Using Diaminoligosulfane and Acid Catalyst

以下是本项目开发的新成果。1.研究了在布朗斯台德酸或金属三氟甲磺酸盐存在下，4，4 '-硫代二吗啉齐聚物与烯烃直接反应合成硫杂环丙烷的反应。因此，在羧酸或对甲苯磺酸存在下，2-金刚烷亚基-9-苯并降冰片烯亚基1与4，4 '-四硫代二吗啉2、4，4'-二硫代二吗啉3和4，4 '-硫代二吗啉4反应，得到相应的硫杂环丙烷。当使用羧酸时，pK_a值越小，反应速率越快。不幸的是，在大多数反应中观察到所得硫杂环丙烷的异构化和分解。发现4，4 '-低聚硫代二吗啉对1的反应性为2> 3> 4。2.研究了4，4 '-二硫代二吗啉3和酸酐直接合成硫杂环丙烷的方法。虽然化合物1和3与高活性酸酐如Tf_2O、TfOAc、Ts_2O和（CF_3CO）_2O反应生成相应的硫杂环丙烷，产率中等，但它们也发生异构化和分解。在过量Ac_2O的存在下，反应不发生异构化和分解，得到了环硫杂环丙烷。2，2 '-联金刚烷亚基5，以及反式-和顺式-环辛烯6和7也在相同条件下反应，得到相应的硫杂环丙烷。3.研究了由N，N-二硫代双唑直接合成硫杂环丙烷的方法。1与N，N-二硫代双苯并咪唑8在无Cu（OTf）_2和Sc（OTf）_3存在下不发生反应，而与N，N-二硫代双（1H-1，2，4-三唑）9在-15 ℃下仍能发生反应。烯烃5-7、顺丁烯、反式和顺式-9，9 '-二苯并降冰片亚甲基8和9也在相同条件下反应得到相应的硫杂环丙烷，并保留烯烃的构型。

The followings are new results developed by the present project. 1. Direct synthesis of thiiranes from alkenes using 4,4'-oligothiodimorpholines in the presence of Bronsted acid or metal triflate was investigated. Thus,2-adamantylidene-9-benzonorbornenylidene 1 reacted with 4,4'-teirathiodimorpholine 2, 4,4'-dithiodimorpboline 3, and 4,4'-thiodimorpholine 4 in the presence of carboxylic acid or ptoluenesulfonic acid to give the corresponding thiiranes. When carboxylic acid was used, the rate of reaction was faster as its pK_a value was smaller. Unfortunately, isomerization and decomposition of the resulting thiirane was observed in most of the reactions. Reactivity of 4,4'-oligothiodimorpholiws toward 1 is found to be 2> 3> 4. 2. The direct synthesis of thiiranes using 4,4'-dithiodimorpholine 3 and arid anhydride was investigated. Although reactions of 1 and 3 with highly reactive acid anhydride such as Tf_2O, TfOAc, Ts_2O, and (CF_3C0)_2O took place to form the corresponding thiiranes in moderate yields, their isomerization and decomposition also occurred. The reaction with excess of Ac_2O proceeded to give the thiiranes without the isomerization and decomposition of the products. 2,2'-Biadamantylidene 5, and trans- and cis-cyclooctene, 6 and 7, also reacted to furnish the corresponding thiiranes under the same conditions. 3. The direct synthesis of thiiranes using N, N-dithiobisazoles was investigated. Although the reaction of 1 with N, N-Dithiobisbenzimidazole 8 in the absence of Cu (Otf)_2 and Sc (Otf)_3 did not occur, that with N,N-dithiobis (1H-1,2,4-triazole) 9 proceeded even at-15℃. The alkenes 5-7, norbornene, and anti- and syn-9,9'-bibenzonorbomenylidenes, 8 and 9 also reacted to furnish the corresponding thiiranes with retention of configuration of the alkenes under the same conditions.