TFA-promoted sulfonation/cascade cyclization of 2-propynolphenols with sodium sulfinates to 4-sulfonyl 2<i>H</i>-chromenes under metal-free conditions

Abstract

A novel, efficient and metal-free cascade sulfonylation/cyclization of 2-propynolphenols with commercially available sodium sulfinates was developed for the synthesis of 4-sulfonyl 2<italic>H</italic>-chromenes under mild conditions.