Nitti Andrea, Osw Peshawa, Calcagno Giuseppe, Botta Chiara, Etkind Samuel I, Bianchi Gabriele, Po Riccardo, Swager Timothy M, Pasini Dario
Department of Chemistry, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
INSTM Research Unit, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Org Lett. 2020 Apr 17;22(8):3263-3267. doi: 10.1021/acs.orglett.0c01043. Epub 2020 Apr 7.
We demonstrate the broad applicability of the annulation protocol combining, in one pot, a direct arylation and cross aldol condensation for the straightforward synthesis at gram-scale of π-extended thiophene-based scaffolds. The regiospecific direct arylation drives the subsequent cross-aldol condensation proceed under the same basic conditions, and the overall protocol has broad applicability in the synthesis of extended aromatics wherein the thiophene ring is annulated with furans, pyridines, indoles, benzothiophenes, and benzofurans. These scaffolds can be further elaborated into π-extended, highly fluorescent oligomers with a central deficient benzothiadiazole unit with up to nine aromatic rings through coupling reactions.
我们展示了环化反应方案的广泛适用性，该方案在一个反应瓶中结合直接芳基化和交叉羟醛缩合反应，可直接以克级规模合成π-扩展的基于噻吩的支架结构。区域特异性直接芳基化驱动后续交叉羟醛缩合反应在相同碱性条件下进行，并且该整体方案在扩展芳烃的合成中具有广泛适用性，其中噻吩环与呋喃、吡啶、吲哚、苯并噻吩和苯并呋喃稠合。通过偶联反应，这些支架结构可进一步转化为具有中心缺电子苯并噻二唑单元、多达九个芳环的π-扩展、高荧光低聚物。
