Ring Expansion of Heterocyclic KeteneN,X-Acetals and 2-Alkylidenedihydroindoles with Methanesulphonyl Azide by [3 + 2] Cycloaddition and Subsequent Extrusion of Molecular Nitrogen
作者:Helmut Quast、Svetlana Ivanova、Eva-Maria Peters、Karl Peters、Hans Georg Von Schnering
DOI:10.1002/jlac.199619961008
日期:1996.10
(route A2 16, 20, 21). In addition, 3 may undergo [3 + 2] cycloreversion into N-sulphonylimine 5 and diazoalkane 6 (route B 13, 17, 25). The configurations of the cyclic N-sulphonylamidines 16b and 21b, the N-sulphonylimine 24 and the N-sulphonylamine 27 are elucidated by means of X-ray diffraction analyses. The ratio of the (useful) ring-expansion reactions vs. the unwanted formation of 5 + 6 is hardly
甲磺酰叠氮化物(2)与分离的1型环状烯酮N,X-缩醛反应,即。10a,d,15b,d和22a–c,或通过相应的2-烷基苯并四氟硼酸2-烷基苯甲唑鎓去质子化而生成的那些,即14a 15a,14b 15b和18 19。环扩展产品是由从中间不稳定的[3 + 2] cycloadducts分子氮的挤压形成3与N个伴随1,2-移(路线A1 12,24)或X(路线A2 16,20,21)。此外,3可能会经历[3 + 2]循环还原为N-磺酰亚胺5和重氮烷6(路线B 13,17,25 )。借助X射线衍射分析阐明了环状N-磺酰胺基16b和21b,N-磺酰亚胺24和N-磺胺27的构型。(有用的)扩环反应与不想要的5 + 6形成之比几乎不受所用溶剂和实验温度的影响,但受潜在迁移原子和α-碳原子上取代基的性质的影响很大原子。