Nitrosoarenes as Nitrogen Source for Generation of Sulfonamides with the Insertion of Sulfur Dioxide under Metal-Free Conditions

Summary of main observation and conclusion A metal-free reaction of nitrosoarenes,aryldiazonium tetrafluoroborates,and sulfur dioxide under mild conditions is developed,giving rise to sulfonamides in moderate to good yields.This transformation proceeds eficiently at room temperature in the presence of cyclohexa-1,4-diene with a broad reaction scope.Good functional group compatibility is observed,including cyano,halo,and ester.A plausi-ble mechanism involving a radical process with the insertion of sulfur dioxide is proposed,and cyclohexa-1,4-diene serves as the reductant during the transformation.