Rh‐catalyzed Tandem Coupling of Sulfonamide with Isonitrile and Amine in Presence of Iodobenzene Diacetate: Direct Access to <i>N</i> ‐Sulfonyl Guanidines

Abstract We report herein a new synthetic pathway for the formation of N ‐sulfonyl guanidine via multicomponent coupling of arylsulfonamide, isonitrile, and amine in the presence of a catalytic amount of Rh(COD)Cl] 2 and iodobenzene diacetate as a promoter. The reaction is presumed to proceed via in situ formation of PhINTs due to the presence of the hypervalent iodine reagent PhI(OAc) 2 in the reaction medium. The addition of PPh 3 has been found to be beneficial in enhancing the catalytic performance of [Rh(COD)Cl] 2 . The formation of the key intermediate, carbodiimide resulted from the reaction between PhINTs and isonitrile which gets converted to the respective sulfonyl guanidine due to the nucleophilic attack of the amine.