Iron-catalyzed deoxygenation and 2-sulfonylation of quinoline <i>N</i>-oxides by sodium sulfinates towards 2-sulfonyl quinolines

<p>An iron(III)-catalyzed protocol towards 2-sulfonyl quinolines from quinoline <i>N</i>-oxides and sodium sulfinates was herein illustrated. The general and direct option featured for high efficiency (up to 91% yields) and good functional compatibilities (27 examples) in the Fe(III)-catalysis. Moreover, free radical mechanism was proposed for the one-pot deoxygenation and sulfonylation reaction based on the results of the control reactions.</p> <p>An novel reaction between quinoline N-oxides and sodium sulfinates for the synthesis of 2-sulfonyl quinolines was herein achieved by an iron(III)-catalyzed system. The general and direct transformation exhibited high efficiency (up to 91% yields) and good functional-groups compatibilities (27 examples). Moreover, free radical mechanism was proposed for the one-pot deoxygenation and sulfonylation reaction based on the results of the control reactions.</p>