Nature Catalysis ( IF 37.8 ) Pub Date : 2021-07-19 , DOI: 10.1038/s41929-021-00653-7 Takahiro Doba 1 , Wataru Sato 1 , Rui Shang 1 , Eiichi Nakamura 1
Regioselective thienyl–thienyl coupling is arguably one of the most important transformations for organic electronic materials. A prototype of ideal organic synthesis to couple two thienyl groups by cutting two C–H bonds requires formal removal of two hydrogen atoms with an oxidant, which often limits the synthetic efficiency and versatility for oxidation-sensitive substrates (for example, donor and hole-transporting materials). Here, we found that diethyl oxalate, used together with AlMe3, acts as a two-electron acceptor in an iron-catalysed C–H activation. We describe the regioselective thienyl C–H/C–H coupling with an iron(III) catalyst, a trisphosphine ligand, AlMe3 and diethyl oxalate under mild conditions. The efficient catalytic system accelerated by ligand optimization polymerizes thiophene-containing monomers into homo- and copolymers bearing a variety of electron-donative π motifs. The findings suggest the versatility of iron catalysis for the synthesis of functional polymers, for which the potential of this ubiquitous metal has so far not been fully appreciated.
中文翻译:
铁催化的区域选择性噻吩基 C-H/C-H 偶联
区域选择性噻吩基-噻吩基偶联可以说是有机电子材料最重要的转变之一。通过切割两个 C-H 键来偶联两个噻吩基的理想有机合成原型需要用氧化剂正式去除两个氢原子,这通常会限制氧化敏感底物(例如,供体和空穴)的合成效率和多功能性。运输材料)。在这里,我们发现草酸二乙酯与 AlMe 3一起使用,在铁催化的 C-H 活化中充当双电子受体。我们描述了区域选择性噻吩基 C-H/C-H 与铁 (III) 催化剂、三膦配体 AlMe 3偶联和草酸二乙酯在温和条件下。通过配体优化加速的高效催化体系将含噻吩的单体聚合成具有各种给电子π基序的均聚物和共聚物。研究结果表明铁催化合成功能聚合物的多功能性,迄今为止,这种普遍存在的金属的潜力尚未得到充分认识。