Hess B Andes
Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37205, USA.
J Am Chem Soc. 2002 Feb 13;124(6):920-1. doi: 10.1021/ja0172823.
Density functional calculations have been carried out for cycloproylidene-, cyclopentylidene-, and tropyllideneallene oxides (7-9) and the reaction pathway for their conversion to the corresponding oxyallyls (10-12) and cyclopropanones (13-15) in order to probe the electronic structure of the intermediate oxyallyls. All three oxyallyls were found to be stabilized with respect to their allene oxides in comparison to the unsubstituted allene oxide and oxyallyl. For 7 and 9 the stabilization can be attributed to the zwitterionic character of the oxyallyls, while for 8 the stabilization can be attributed to its diradical character. This suggests that oxyallyl is capable of "adapting" to its local environment. Calculations predict that oxyallyl 12 should be an observable intermediate in the absence of nucleophiles, since it is calculated to be of lower energy than either the allene oxide 9 or the cyclopropanone 15.
已对环丙叉基、环戊叉基和草鎓叉基丙二烯氧化物（7 - 9）进行了密度泛函计算，并研究了它们转化为相应的烯丙氧基（10 - 12）和环丙烷酮（13 - 15）的反应途径，以探究中间烯丙氧基的电子结构。与未取代的丙二烯氧化物和烯丙氧基相比，发现所有这三种烯丙氧基相对于它们的丙二烯氧化物都更稳定。对于7和9，这种稳定性可归因于烯丙氧基的两性离子特性，而对于8，稳定性可归因于其二自由基特性。这表明烯丙氧基能够“适应”其局部环境。计算预测，在没有亲核试剂的情况下，烯丙氧基12应该是可观察到的中间体，因为计算得出它的能量低于丙二烯氧化物9或环丙烷酮15。
