两种单取代二噻吩并[2,3-b:3′,2′-d]噻吩衍生物的开环反应的研究

Study on the Ring-Opening Reaction of Two Mono-Substituted Dithieno[2,3-b:3′,2′-d]Thiophenes

以2,5-二(三甲基硅基)二噻吩并[2,3-b:3′,2′-d]噻吩为原料,有效地制备了两种单取代的二噻吩并[2,3-b:3′,2′-d]噻吩衍生物,2-三甲基硅基二噻吩并[2,3-b:3′,2′-d]噻吩与二噻吩并[2,3-b:3′,2′-d]噻吩-2-甲酸乙酯.研究了这两种非对称产物在一当量正丁基锂存在条件下的不对称开环现象,中间体锂盐经DMF猝灭可各自有效地得到两种同分异构体,即丁硫基[3,3′]联噻吩醛衍生物,同时发现具给电子基团(三甲基硅基)的底物具有较显著的开环选择性,而具吸电子基团(酯基)底物的开环选择性不太显著.

Starting from 2,5-bis（trimethylsilyl）dithieno[2,3-b：3′,2′-d]thiophene,two mono-substituted dithieno[2,3-b：3′,2′-d]thiophenes： 2-trimethylsilyl-dithieno[2,3-b：3′,2′-d]thiophene and ethyl dithieno[2,3-b：3′,2′-d]thiophene-2-carboxylate were synthesized efficiently.Their ring-opening reaction occurred in presence of n-BuLi at low temperature.After quenching with DMF,the derivatives of 2＇-butylsulfanylbithiophenyl-2-carbaldehyde were obtained effectively.The selectivity of ring opening reaction is good to the substrate with EDG（TMS group）,but poor to that with EWG（ester gourp）.