analysis. The unprecedented 3 → 4 ring expansion process is argued to be driven by an ambivalent aromatic vs antiaromatic character (or loss of aromaticity) of the primary phosphonium product. On the basis of DFT calculations, a mechanism involving a concerted 1,4-hydride shift/electrocyclization process as the rate-determining step is proposed and discussed vs possible alternatives.
尝试通过用双
二异丙基氨基环
丙烯四
氟硼酸酯对α-
氨基膦进行P-季
铵化来制备环
丙烯基salts盐,导致氮杂
环丁烷-2-亚甲基甲基phosph为意外的异构体,收率为57-85%。在X射线晶体学分析的基础上讨论了产品的基本结构。据认为,空前的3→4环膨胀过程是由主要phospho产物的矛盾的芳香族与反芳香族特征(或丧失芳香性)驱动的。在DFT计算的基础上,提出了一种涉及协同的1,4-
氢化物转移/电环化过程作为速率确定步骤的机理,并讨论了可能的替代方案。