Direct Synthesis of Thiiranes from Alkenes Using Diaminoligosulfane and Acid Catalyst

以下是本项目取得的新成果。1. 研究了在Bronsted酸或金属三氟酸盐存在下，用4,4′-低硫代二morpholines由烯烃直接合成硫烷。因此，在羧酸或甲苯磺酸存在下，2- adamantyliden9 - benzonorbornenyliden1与4,4'-二硫代二硫代啉2,4,4 '-二硫代二硫代啉3和4,4'-硫代二硫代啉4反应生成相应的硫代烷。羧酸的pK_a值越小，反应速度越快。不幸的是，在大多数反应中观察到产生的硫代烷的异构化和分解。发现4,4'-寡硫二形态聚合物对1的反应性为2 b> 3 b> 4。2. 研究了以4,4′-二硫代二morpholine 3和干燥酸酐为原料直接合成硫烷的方法。虽然1和3与高活性酸酐如Tf_2O、TfOAc、Ts_2O和（CF_3C0）_2O反应生成相应的中等产率的硫烷，但也发生了异构化和分解。在过量Ac_2O的条件下，生成了噻烷，产物没有异构化和分解。在同样的条件下，2,2′-双金刚烷二烯5和反式环烯和顺式环烯6和顺式环烯7也反应生成相应的硫烷。3. 研究了N， N-二硫代双唑直接合成硫烷的方法。虽然在没有Cu (Otf)_2和Sc (Otf)_3的情况下，1与N，N-二硫代双苯并咪唑8的反应没有发生，但与N，N-二硫代双硫代（1h -1,2,4-三唑）9的反应在15℃下仍能进行。烯烃5-7、降冰片烯、反-和-9,9′-双苯并甲炔烯、8和9也反应生成相应的噻烷，在相同条件下保留了烯烃的构型。

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.