Copper(I)-Catalyzed Cascade Sulfonimidate to Sulfonamide Rearrangement: Synthesis of Imidazo[1,2-<i>a</i>][1,4]diazepin-7(6<i>H</i>)-one

A novel strategy of copper­(I)-catalyzed cascade intramolecular nucleophilic attack on <i>N</i>-sulfonylketenimine followed by rearrangement of sulfonimidates to sulfonamides resulting in a library of substituted 8,9-dihydro-5<i>H</i>-imidazo­[1,2-<i>a</i>]­[1,4]­diazepin-7­(6<i>H</i>)-ones has been developed