BF₃•Et₂O Promoted Dienone-Phenol Type Rearrangement to Synthesize Phosphepine with Aggregation Induced Luminescence (AIE) Effect

Abstract

Very recently, phosphepines has emerged as a new luminogen. Further explorations of this new motif in optical materials have been hampered by the lack of general and practical methods for their synthesis and derivation. The rearrangement of dienones promoted by acid or base is widely used in the preparation of phenols. A series of phosphepines with aggregation induced luminescence (AIE) effect were synthesized by the dienone-phenol rearrangement reaction of spirodienone six-membered phosphacycles in the presence of BF3•Et2O. Keywords dienone-phenol rearrangement; phosphepine; aggregation-induced emission (AIE); BF3•Et2O 有机磷化合物在有机小分子催化、生物探针及有机 光电材料等领域得到了广泛应用 [1] , 其中在 π 共轭体系 中引入磷原子是一种高效调节共轭材料光电性能的方 法 [2] . 早期报道的磷杂环庚三烯在室温下会快速分解释 放出芳烃和活泼的亚膦烯中间体 [3] . 通过对磷中心的空 间屏蔽, 或者将磷杂环庚三烯引入到稠环体系中可以获 得稳定的磷杂环庚三烯类化合物 [4] . 合成此类型磷杂七 元环的最常用的方法 [5] 是通过二溴芳烃 A1 的双锂化, 再与二氯化磷反应构筑磷杂七元环 A2 (Scheme 1, a), Hissler 等 [6] 利用该方法合成了双噻吩并磷杂七元环, 并 将其用于有机场效应晶体管(OFET)制备. 该课题组还 设计合成了双溴代萘基膦 A3 [7] , 然后通过分子内的 C-C 键的偶联来构筑含有双萘结构的磷杂七元环 A4