Mild Copper-Catalyzed, <span style="font-variant: small-caps">l</span>-Proline-Promoted Cross-Coupling of Methyl 3-Amino-1-benzothiophene-2-carboxylate

Abstract

Cu-catalyzed N-arylation is a useful tool for the chemical modification of aromatic heterocycles. Herein, an efficient carbon–nitrogen cross-coupling of methyl 3-amino-1-benzothiophene-2-carboxylate with a range of (hetero)aryl iodides using CuI, l-proline and Cs2CO3 in dioxane at moderate temperature is described. The procedure is an extremely general, relatively cheap, and experimentally simple way to afford the N-substituted products in moderate to high yields. The structures of the new heterocyclic compounds were confirmed by NMR spectroscopy and HRMS investigation.

Keywords

• benzo[<i>b</i>]thiophene
• copper catalysis
• l-proline%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> <span style="font-variant: small-caps">l</span>-proline
• <i>N</i>-arylation
• aryl iodides