Friedel-crafts cyclisation—VI11Part V.J.M. Allen, K.M. Johnston and R.G. Shotter, Chem. & Ind. 108 (1976).
作者:J.M. Allen、K.M. Johnston、J.F. Jones、R.G. Shotter
DOI:10.1016/0040-4020(77)80317-7
日期:——
Polyphosphoric acid-catalysed cyclisation of derivatives of crotonophenone and chalcone is shown to be a general reaction which occurs without migration of aryl substituents evident with other Friedel-Crafts catalysts. Two other reactions, however, may intervene: hydrogenation and α-carbonyl cleavage. Thus 4-bromochalcone gives 3 - (p - bromophenyl) -1 - phenylpropan -1 - one, 3 - (p - bromophenyl)indan
巴豆酮和查尔酮衍生物的多磷酸催化环化反应是一般反应,在没有其他Friedel-Crafts催化剂明显的芳基取代基迁移的情况下发生。但是,可能还会发生另外两个反应:氢化和α-羰基裂解。因此,4-溴查耳酮得到3-(对-溴苯基)-1-苯基丙烷-1-1、3- (对-溴苯基)茚满-1-1和一些苯甲酸。与报道的α,β-不饱和酯和二乙烯基酮环化的机理相比,讨论了环化的机理。中间Wheland配合物的形成被认为是可旋转的。