Scheme 1) in which the boranediyl intermediate has inserted into an o-Me-ring C−C σ-bond to form a borafluorenyl structure incorporating boron in a delocalized five-membered ring. Boranediyl insertion into C−C σ-bonds, as distinct from boranediyl induced rearrangements involving CC cleavage in delocalized aromatic substrates, is unknown. The main difference between the structures of these products is that
芳基
硼二卤化物 2,6-Mes2C6H3BX2 (X = Cl (1); Br (2)) 和 2,6-Trip2C6H3BBr2 (3) (Mes = 2,4,6-Me3C6H2- 和 Trip = 2,4,6-i-Pr3C6H2-) 进行了描述。在
乙醚中用
锂金属处理 2 得到新型 9-
硼芴基
锂化合物 4 和 5(参见方案 1),其中
硼烷二基中间体已插入 o-Me-环 C-C σ-键以形成
硼芴基结构在离域五元环中加入
硼。
硼烷二基插入 C−C σ-键,与
硼烷二基诱导的重排不同,涉及离域芳族底物中的 CC 裂解,这是未知的。这些产品结构之间的主要区别在于,由于溶剂化醚的数量减少,5 被二聚化。