Alkynylated Diazadioxaacenes: Syntheses and Properties

We report the successful synthesis of a series of ethynylated dioxa­diazaacenes and investigate their properties. We developed a modular Cu-based catalytic procedure to build up [1,4]­dioxino­[2,3-b]­pyrazine motifs starting from only a few building blocks. TIPS-acetylene-substituted benzene-1,2-diol and naphthalene-2,3-diol were reacted with 2,3-dichloropyrazine, 2,3-dichloroquinoxaline, and 2,3-dichlorobenzoquinoxaline to give a set of six novel and well-soluble dioxadiazaacenes. Different reaction conditions for the coupling were tested. Copper catalysis is most effective and gave the best yield of dioxadiazaacenes. The resulting azaoxaacenes were characterized in terms of optical and electronic properties and crystal packing.本工作成功合成了一系列乙炔基取代的二氧二氮杂并苯（dioxadiazaacenes），并对其相关性质开展了系统研究。我们开发了一种模块化铜基催化合成策略，可仅通过少量结构砌块即可构建[1,4]二氧六环并[2,3-b]吡嗪结构单元。将三异丙基硅基（TIPS）乙炔基取代的苯-1,2-二醇与萘-2,3-二醇，分别与2,3-二氯吡嗪、2,3-二氯喹喔啉、2,3-二氯苯并喹喔啉进行偶联反应，得到了六种结构新颖且溶解性优异的二氧二氮杂并苯。我们对该偶联反应的多种反应条件进行了筛选，结果表明铜催化体系效果最优，可获得二氧二氮杂并苯的最高产率。所得到的氮氧杂并苯的光学、电子性质以及晶体堆积特征均得到了系统表征。