Polylithiumorganic Compounds - 19.
作者:Adalbert Maercker、Volker E.E. Daub
DOI:10.1016/s0040-4020(01)86961-1
日期:1994.2
α-methylbenzylidenecyclopropane (32c) this rearrangement was shown to occur intermolecularly via a trilithiumorganic compound 56. The suggested mechanism of these reductive metalation reactions via a bisected radical anion 87 where the lithium is mainly bound to the cyclopropyl carbon atom and oriented syn to the phenyl ring, was supported by MNDO (geometries) and ab initio (energies) calculations.
取决于取代基,α-取代的亚苄基环丙烷(32)或多或少容易与锂粉尘(2%钠)在乙醚中反应,从而仅发生环丙烷σ-键顺式对苯环的区域选择性断裂。在升高温度时,由于剧烈相互作用而最初形成的1,3-二锂有机化合物通过1,6-质子移位而重排为双桥的1,4-二硫代化合物。对于α-甲基亚苄基环丙烷(32c),这种重排显示是通过三锂有机化合物56在分子间发生的。这些还原金属化反应的建议机理是通过两等分的自由基阴离子87进行的,其中锂主要与环丙基碳原子键合且取向为正构。 MNDO(几何形状)和从头算(能量)计算支持了对苯环的连接。