Bromination and Azidation Reactions of 2-Styrylchromones. New Syntheses of 4(5)-Aryl-5(4)-(2-chromonyl)-1,2,3-triazoles
作者:Artur M. S. Silva、Judite S. Vieira、Cristela M. Brito、Jos� A. S. Cavaleiro、Tam�s Patonay、Albert L�vai、Jos� Elguero
DOI:10.1007/s00706-003-0125-y
日期:2004.3.1
strongly electron-withdrawing group hindered the bromination. The dehydrobromination of 2-(2-aryl-1,2-dibromoethyl)chromones with triethylamine gave a diastereomeric mixture of ( E )- and ( Z )-2-(α-bromostyryl)chromones. Some novel 4(5)-aryl-5(4)-(2-chromonyl)-1,2,3-triazoles have been obtained from the reactions of 2-(2-aryl-1,2-dibromoethyl)chromones, 2-(α-bromostyryl)chromones, and 2-styrylchromones
用两个摩尔当量的三溴化吡啶鎓对带有电子中性取代基的2-苯乙烯基色酮进行溴化反应,得到2-(2-芳基-1,2-二溴乙基)色酮和3-溴-2-(2-芳基-1,2-二溴乙基)色酮。由于其C(2)= C(3)和Cα = Cβ双键的较高反应性,其B环上供电子取代基的存在导致化合物的混合物,而强吸电子基团则受阻溴化。2-(2-芳基-1,2-二溴乙基)色酮与三乙胺的脱氢溴化反应生成( E )-和( Z )-2-(α-溴代苯乙烯基)色酮。从2-(2-芳基-1,2-二溴乙基)色酮2的反应中获得了一些新颖的4(5)-芳基-5(4)-(2-chromonyl)-1,2,3-三唑-(α-溴代苯乙烯基)色酮和2-苯乙烯基色酮与叠氮化钠 2-苯乙烯基色酮与叠氮化钠的反应更有效,更通用,可构成一锅合成4(5)-芳基-5(4)-(2-苯甲酰基)-1,2,3-三唑的合成方法制备在其芳基环上带有给电子或吸电子取代基的1,2,3