Improved, Odorless Access to Benzo[1,2-d;4,5-d′]- bis[1,3]dithioles and Tert-butyl Arylsulfides via C-S Cross Coupling
作者:Kevin Kopp、Olav Schiemann、Nico Fleck
DOI:10.3390/molecules25163666
日期:——
Benzo[1,2-d;4,5-d′]bis[1,3]dithioles are important building blocks within a range of functional materials such as fluorescent dyes, conjugated polymers, and stable trityl radicals. Access to these is usually gained via tert-butyl aryl sulfides, the synthesis of which requires the use of highly malodorous tert-butyl thiol and relies on SNAr-chemistry requiring harsh reaction conditions, while giving
苯并[1,2-d;4,5-d']双[1,3]二硫醇是荧光染料、共轭聚合物和稳定的三苯甲基自由基等一系列功能材料中的重要组成部分。获得这些通常是通过叔丁基芳基硫化物获得的,其合成需要使用具有强烈恶臭的叔丁基硫醇,并且依赖于需要苛刻反应条件的 SNAr 化学,同时产率低。在目前的工作中,S-叔丁基异硫脲溴化物成功地用作叔丁基硫醇的无味替代品。CS 键的形成在钯催化下进行,硫醇盐在原位形成,导致叔丁基芳基硫化物的产率高。苯并[1,2-d;4,5-d']双[1,3]二硫醇的随后形成是用三氟甲磺酸钪(III)实现的,三氟甲磺酸钪是一种比通常使用的路易斯酸危害更小的试剂,例如,三氟化硼或四氟硼酸。这使得能够方便且环保地获得高产率的苯并[1,2-d;4,5-d']双[1,3]二硫醇。