Synthesis of Benzothienobenzofurans via Annulation of Electrophilic Benzothiophenes with Phenols
Akhil R Krishnan, Sheba Ann Babu, Nitha P. R., Jagadeesh Krishnan, Jubi John*
We have developed a metal-free, mild and green synthetic route towards benzothieno[3,2-b]benzofurans by the annulation of 3-nitrobenzothiophene with phenols. The reaction was found to be general with a range of substituted phenols. In addition, we could extend the methodology for the synthesis of pentacenes and could demonstrate the synthesis in gram-scale. Moreover, we extended the strategy for the synthesis of benzothieno[2,3-b]benzofurans by starting from 2-nitrobenzothiophenes.
Org. Lett. 2021, 23, 1814–1819