1,3,5-三[(4’-乙炔基苯基)乙炔基]苯的合成

设计了多种合成路线制备芳香炔基树枝状化合物中间体1,3,5-三(4’-乙炔基苯基)乙炔基]苯,通过一系列的合成路线和反应条件的对比,发现多官能团的端基炔化合物与芳基溴化合物之间发生多重Sonogashira反应时,常会生成不同取代程度的极性相似化合物,因而难以分离.采用多官能团的端基炔化合物与芳基碘化合物反应可以避免这种情况.最终确定以1,3,5-三溴苯和2-甲基-3-丁炔-2-醇为原料,制得中间产物1,3,5-三乙炔基苯;再以对碘苯胺和三甲基硅乙炔为原料,经重氮化化、卤代反应制得4-三甲基硅乙炔基碘苯;后者与1,3,5-三乙炔苯经Sonogashira反应、裂解去保护反应,制得化合物1,3,5-三(4’-乙炔基苯基)乙炔基]苯.用1H NMR,13C NMR,元素分析等表征手段确认了中间体及最终产物的结构.

Synthesis of 1,3,5-Tris[(4'-ethynylphenyl)ethynyl]benzene

everal synthetic routes were designed to prepare 1,3,5-tris(4-ethynylphenyl)ethynyl]benzene.The synthetic routes and reaction conditions were contrasted and discussed,when multiple Sonogashira reactions were occurred between multifunctional alkyne-terminal compounds and aromatic bromine compounds,the different substitution degree compounds with similar polarity were obtained,and they were difficult to separate.Whereas the reactions between multifunctional alkyne-terminal compounds and aromatic iodine compounds can avoid this situation.1,3,5-Tribromobenzene reacted with 3-methylbutynol to afford 1,3,5-tris(3’-hydroxy-3’-methyl-but-1’-ynyl)benzene,then 1,3,5-triethynylbenzene was obtained by the cleavage reaction of the compound in presence of potassium hydroxide and toluene.On the other hand,using 4-iodoaniline and trimethyl silyl acetylene as raw materials,4-trimethylsiylethynyl iodobenzene was synthesized by diazo reaction and halogenation.Therefore,1,3,5-tris(4’-ethynylphenyl)ethynyl]benzene was prepared by the cleavage reaction of the 1,3,5triethynylbenzene and 4-trimethylsiylethynyl iodobenzene.The structures of the target compound and intermediates were confirmed by1H NMR,13C NMR techniques and element analysis.