Access to 3-aminobenzothiophenes and 3-aminothiophenes fused to 5-membered heteroaromatic rings through 6π-electrocyclization reaction of keteniminium salts
作者:Amandine Kolleth、Simona Müller、Alexandre Lumbroso、Gamze Tanriver、Saron Catak、Sarah Sulzer-Mossé、Alain De Mesmaeker
DOI:10.1016/j.tetlet.2018.06.049
日期:2018.8
5-membered heteroaromatic rings as thiophenes, furans and pyrroles through a 6π-elctrocyclization reaction of keteniminium salts. We investigated various substituents not only on the aromatic rings, but also at C-2 and on the nitrogen atom of the keteniminium salt. In particular, we have determined the electronic requirements of the nitrogen substitution to secure the efficient formation of the corresponding
我们描述了通过酮亚胺盐的6π-电子环化反应将3-氨基苯并噻吩和3-氨基噻吩与5-元杂芳族环稠合为噻吩,呋喃和吡咯的一般方法。我们不仅研究了芳环上的各种取代基,而且还研究了烯酮铵盐的C-2和氮原子上的各种取代基。特别是,我们确定了氮取代的电子要求,以确保有效形成相应的酮亚胺盐。pK a之间的明确关系确定胺的形成导致烯属铵盐的形成,并确定了苯并噻吩的收率,应将其广泛应用于涉及这些中间体的其他反应中。通过竞争反应和DFT计算,获得了对该6π-电环化反应的难易程度的其他见解。