A facile and general synthesis of various N-substituted cyanamides was accomplished by the Tiemann rearrangement of amidoximes with benzenesulfonyl chlorides (TsCl or o-NsCl) and DIPEA.

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CuI-Catalyzed intramolecular aminocyanation of terminal alkynes in N-(2-ethynylphenyl)-N-sulfonylcyanamides was initiated by the formation of Cu-acetylide to trigger N-CN bond cleavage of the N-sulfonylcyanamide moiety followed by CN migration to form a β-cyano Cu-vinylidene intermediate. Subsequently, the indole ring closure furnished the corresponding 1-sulfonyl-3-cyanoindoles.

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The reaction of methyl anthranilates with N-arylcyanamides in the presence of p-TsOH in t-BuOH under reflux afforded predominantly 3-arylquinazolin-4-ones. In contrast, the reaction of the same reactants with TMSCl in t-BuOH at 60 °C followed by the Dimroth rearrangement in aqueous ethanolic sodium hydroxide gave exclusively the regioisomers, 2-(N-arylamino)quinazolin-4-ones. The regioselective synthesis of N-aryl-substituted 2-aminoquinazolin-4-ones can be further applied to the synthesis of benzimidazo[2,1-b]quinazolin-12-ones.