Unified Approach to (Thio)chromenones via One-Pot Friedel–Crafts Acylation/Cyclization: Distinctive Mechanistic Pathways of β‑Chlorovinyl Ketones

A facile synthetic method to chromenones and thiochromenones has been developed using a one-pot Friedel–Crafts acylation of alkynes with suitably substituted benzoyl chlorides. This unified approach to (thio)­chromenones is readily applicable to aryl- and alkylalkynes where the stereochemically well-defined β-chlorovinyl ketone intermediates undergo distinctively different cyclization pathways. The ready availability of both starting materials, alkynes and benzoyl chlorides, coupled with the experimental simplicity makes the current synthetic method to (thio)­chromenones fast, efficient, and practical

Palladium-Catalyzed Aerobic Oxidative Hydroamination of Vinylarenes Using Anilines: A Wacker-Type Amination Pathway

A palladium-catalyzed intermolecular hydroamination of vinylarene derivatives using anilines has been developed for the first time under aerobic conditions, where the regioselective formation of <i>N</i>-arylketimines is accomplished. The current aerobic <i>oxidative</i> hydroamination pathway of anilines is distinct from that of palladium-catalyzed hydroamination reactions that proceed to give <i>sec</i>-arylethylamine and arylethylamine derivatives, identifying a longstanding missing reaction pathway, Wacker-type amination, to <i>N</i>-arylketimines using anilines. The ready availability of both starting materials, vinylarenes and anilines, offers an attractive and facile synthetic route to <i>N</i>-arylketimines in good to excellent yields