One-pot sequential combination of multi-component and multi-catalyst: synthesis of 5-aminobenzofurans from aminophenol and ketene acetals

The reaction between p-aminophenols 1 and various ketene acetals 2 in the presence of hypervalent iodine is described. The results show that 2- and 3-substituted 5-sulfonamidobenzofurans 3 are obtained in moderate to good yields from p-aminophenols and ketene acetals.