Regiodivergent Annulation Reactions of Chalcones to Indenones and Indanones with C1 Reagents.

Abstract

One-pot direct regiodivergent annulations of chalcones, as exemplified by the drug metochalcone and a bioactive dichloro-substituted chalcone with a quinoline ring, to indanones and indenones are conveniently achieved with single-carbon reagent Kukhtin-Ramirez adducts. A Cs2CO3-promoted unusual selective cleavage of the cyclopropyl C-C bond distal to the strong carbonyl acceptor, further driven to completion by follow-up regiodivergent annulations via Pd(OAc)2-catalyzed Heck reaction or Cs2CO3-mediated SNAr process, is key for the success.