One‐Pot Synthesis of 2‐(alkylsulfanyl)quinolines from Aryl Isothiocyanates and Allenes or Alkynes

In this work, a conceptually novel approach to diversely substituted 2‐(alkylsulfanyl)quinolines is described. The approach includes the assembly of the target molecules from allenic or acetylenic carbanions, aromatic isothiocyanates, and alkylating agents. The process proceeds in a single synthetic operation via the formation and 6π‐electrocyclization of N‐aryl‐1‐aza‐1,3,4‐trienes, R2R3C=C=C(R1)C(SAlk)=NAr, with the participation of the carbon‐carbon double bond of the phenyl group and the azadiene fragment of the azatrienic system.