New method for the acylation of benzofurans toward the synthesis of 6H-indeno[2,1-b]benzofuran-6-ones and 2,2-bibenzofurans

Abstract

We have developed a TFAA-mediated acylation of benzofurans using carboxylic acids as acylating agents. The reaction does not require the aid of Lewis acid catalysts, and lead to the regioselective formation of 2-acyl benzofurans. Among these, 2-bromophenylacyl benzofurans and 2-(2-bromophenyl)acetyl benzofurans could be converted into 6H-indeno[2, 1-b]benzofuran-6-ones and 2, 2'-bibenzofurans, respectively.