Experimental and Theoretical Characterization of the Aromatization, Epimerization, and Fragmentation Reactions of Bi-2H-azirin-2-yls Prepared from 1,4-Diazidobuta-1,3-dienes
作者:Klaus Banert、Frank Köhler、Antje Melzer、Ingolf Scharf、Gerd Rheinwald、Tobias Rüffer、Heinrich Lang、Rainer Herges、Kirsten Heß、Nugzar Ghavtadze、Ernst-Ulrich Würthwein
DOI:10.1002/chem.201101220
日期:2011.8.29
isomerization were postulated. In the case of meso‐ and rac‐22, nearly quantitative formation from diazide 21, isolation as stable solids, and complete characterization were possible. On the thermolysis of 22, aromatization to 23 was only a side reaction, whereas equilibration of meso‐ and rac‐22 and fragmentation, which led to alkyne 24 and acetonitrile, dominated. Prolonged irradiation of 22 gave mainly
1,4- Diazidobuta -1,3-二烯(Ž,Ž) - 10,17,和21被光分解和thermolyzed得到哒嗪13,20,和23分别。为了解释这些芳香族终产物,高度应变双2的产生ħ -azirin -2- YLS 12,19,和22和它们的价异构化被假定。在的情况下,内消旋-和外消旋- 22,几乎定量形成从二叠氮化物21,作为稳定固体的分离以及完整的表征都是可能的。在22的热解中,芳构化到23只是一个副反应,而内消旋和rac - 22的平衡以及碎片化(导致炔24和乙腈)占主导地位。长时间照射22主要得到嘧啶25。不仅在bi-2 H -azirin-2-yls 22的情况下,而且在简单的螺环2 H- azirine 29上都观察到2 H azirine单元C-2处构型的变化。在相对较低的温度下(75°C)。还通过高级量子化学计算研究了rac - 22的片段化,从而生成炔烃24和两