Structural fluxionality in the tricyclo[3.3.1.0]nona-3,6-dienyl and bicyclo[3.2.2]nona-2,6,8-trienyl radicals
作者:John C. Walton
DOI:10.1039/p29890002169
日期:——
E.s.r. observation of radicals derived from 9-bromotricyclo[3.3.1.0]nona-3,6-diene, and related compounds, showed that they rearrange by β-scission to bicyclo[3.2.2]nona-2,6,8-trienyl radicals extremely rapidly; the latter radicals have hyperfine splittings similar to those of allyl radicals. 9-Deuterio- and 2-deuterio-9-bromotricyclo [3.3.1.0]nona-3,6-diene were reduced with tributyltin hydride. The
Esr观测从9-溴三环[3.3.1.0] nona-3,6-二烯和相关化合物衍生的自由基,表明它们通过β断裂重排为双环[3.2.2] nona-2,6,8-三烯基极端激进;后者的自由基具有与烯丙基相似的超精细分裂。用氢化三丁基锡还原9-氘-和2-氘-9-溴三环[3.3.1.0] nona-3,6-二烯。双环[3.2.2] nona-2,6,8-三烯和三环[3.3.1.0] nona-3,6-二烯产物中氘加扰的模式表明,中间基团参与简并重排序列,使它们在三个维度上具有完全可变性。这两个自由基在ca处处于平衡状态。375 K,但bicyclotrienyl物种是一个因素更重要的CA。10 2。实验结果和MNDO半经验计算都没有提供任何证据表明自由基对中额外的热力学稳定性超出烯丙基离域的预期范围。