Sodium dithionite initiated addition of 1-bromo-1-chloro-2,2,2-trifluoroethane to allylaromatics
作者:Jolanta Ignatowska、Wojciech Dmowski
DOI:10.1016/j.jfluchem.2006.01.007
日期:2006.6
hexanes resulted in double dehydrohalogenation affording, in good yields, conjugated dienes 4 (1,1,1-trifluoro-5-phenyl-2,4-pentadienes) terminated with the CF3 group at the one end and the phenyl group at the opposite end. These dienes were found to be sufficiently reactive to undergo Diels-Alder condensation with active dienophiles to give trifluoromethylated carbocycles. The reactions of CF3CHClBr with
连二亚硫酸钠有效地促进1-溴-1-氯-2,2,2-三氟乙烷到烯丙基苯1的末端双键的添加。反应在MeCN / H 2 O中进行,以摩尔比为3:1的1-(2-溴-4-氯-5,5,5-三氟戊基)苯2的非对映异构体以及少量的其还原型脱溴产品3。2和3的总产率取决于1中芳环取代基的性质。用DBU在回流的己烷中处理加合物2导致两次脱卤化氢反应,并获得高收率的共轭二烯4(1,1,1-三氟-5-苯基-2,4-戊二烯)的一端是CF 3基,另一端是苯基。发现这些二烯具有足够的反应性,可以与活性的亲二烯体进行狄尔斯-阿德耳缩合反应,得到三氟甲基化的碳环。CF 3 CHClBr与烯丙基杂环的反应不太成功,导致难以分离的化合物的混合物或聚合树脂的收率低。