Regiocontrol of ring cleavage and cycloaddition of oxiranes catalyzed by organotin- and organoantimony halides

环氧乙烷是工业上可用的有用试剂，但太不稳定，不能在酸性或碱性条件下处理。因此，环氧环己烷裂解的完全区域控制是现代化学中一个重要而严重的问题。在本研究中，本研究取得了以下成果。在有机锡卤碱络合物存在下，与异氰酸酯、碳二亚胺在非常温和的条件下，通过环氧乙烷的裂解反应生成相应的3，5-二取代杂环化合物。相反，Ph_4SbI促进了环氧烷的裂解反应，高产率地得到了3，4-二取代的异构型杂环化合物。后一种环加成反应到目前为止还没有报道。另一方面，在烯酮与环氧乙烷的反应中，SN催化剂和Sb催化剂分别生成了1，3-二氧杂环戊烷和-内酯的衍生物，因此这两种催化剂的补偿使用有望在有机合成中得到广泛的应用。Ph_4SbOTf催化胺与环氧乙烷的反应。在完全无水条件下，在有催化量的Ph_4SbOTf存在下，反应进行。此外，这种催化剂允许使用等摩尔量的胺，尽管过量在传统体系中是不可忽视的。

Oxiranes are industrially available and useful reagents, but too unstable to treat under acidic or basic conditions. Complete regiocontrol of the oxirane-ring cleavage, so, is a significant and serious problem in modern chemistry. In this study, following results were obtained on this subject.1. Cycloaddition of monosubstituted oxiranes with heterocumulenes.In the presence of organotin halide-base complex, the reactions with isocyanates, carbodiimides proceeded via -cleavage of oxirane to furnish the corresponding 3,5-disubstituted heterocyclic compounds under very mild conditions. On the contrary, Ph_4SbI promoted the -cleavaged reaction of oxiranes to gave isomeric heterocyclic compounds, 3,4-disubstituted ones, in high yields. The latter type of cycloaddition has not been reported so far. On the other hand, in the reaction of ketene with oxiranes SN catalyst and SB catalyst gave 1,3-dioxolane and -lactone derivatives, respectively.Thus, compensatable use of the both catalysts would be expected to be adopted widely in organic synthesis.2. Reaction of amines with oxiranes catalyzed by Ph_4SbOTf.Tile reaction was effected under complete anhydrous conditions in the presence of catalytic amounts of Ph_4SbOTf. Moreover, this catalyst allowed the use of an equimolar amount of amine, although excess amounts have been indespensable in conventional systems.