A transition metal‐free iodosobenzene‐promoted direct oxidative 3‐arylation of quinoxalin‐2(H)‐ones was developed using various arylhydrazines under air. The protocol affords a variety of 3‐arylquinoxalin‐2(H)‐one derivatives in moderate to good yields. This method provides a rapid access to biologically interesting benzo[g]quinoxalinones and pyrido[3,4‐b]pyrazinones. The present methodology features high functional group tolerance including base‐sensitive groups as well as allyl‐ and benzyl‐substituted quinoxalin‐2(H)‐ones under mild reaction conditions.magnified image

An efficient and novel annulation protocol for the construction of diverse and polyfunctionalized γ-pyrones via an InBr3-catalyzed reaction is described.

An efficient protocol for the construction of 3‐carbonyl functionalized 4‐pyrones has been developed using a transition‐metal free thermal cascade reaction of diazodicarbonyls with β‐enamino esters or β‐enamino ketones. This reaction proceeds via cascade carbene generation, ketene formation via thermal Wolff‐rearrangement, nucleophilic addition, intramolecular cyclization, and elimination. This protocol provides a rapid synthetic route to diverse 2,3,5‐trisubstituted 4‐pyrone derivatives.magnified image

In(III)‐Catalyzed O‐annulation of cyclic diazodicarbonyl compounds with 2‐naphthols, 6‐quinolinol, β‐tetralone, and 9‐phenanthrol is developed. This novel synthetic strategy paves a facile and desired access to diverse and functionalized benzochromones. This imperative protocol involves domino carbene generation, ketene formation through Wolff‐rearrangement, nucleophilic addition, H‐migration, intramolecular cyclization, and elimination of water.