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

氧环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，对氧环裂解的完全区域控制是现代化学中一个重要而严肃的问题。在本研究中，得到了以下结果：单取代氧烷与杂环烯的环加成。在有机卤化锡碱配合物存在下，与异氰酸酯、碳二酰亚胺在非常温和的条件下通过氧环裂解生成相应的3,5-二取代杂环化合物。相反，Ph_4SbI促进了氧烷的-裂解反应，得到了高产率的3,4-二取代异构杂环化合物。后一种类型的环加成迄今尚未报道。另一方面，在烯酮与氧环烷的反应中，SN催化剂和SB催化剂分别生成1,3-二恶氧烷和-内酯衍生物。因此，这两种催化剂的可补偿使用有望在有机合成中得到广泛采用。Ph_4SbOTf催化胺与氧烷的反应。在Ph_4SbOTf的催化量存在下，在完全无水条件下对Tile反应进行了影响。此外，这种催化剂允许使用等摩尔量的胺，尽管过量的胺在传统系统中是必不可少的。

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.