Palladium-Catalyzed Domino Carbopalladation/Carbonylative Cyclization: Synthesis of Heterocycles bearing Oxindoles and 3-Acylbenzofuran/3-Acylindole Moieties

Abstract

A novel and straightforward methodology for palladium-catalyzed carbopalladation-initiated domino carbonylative cyclization to construct bisheterocycles has been established. With TFBen as an efficient and convenient CO source, the protocol is capable of generating oxindole and 3-acylbenzofuran/3-acylindole moieties from the corresponding N-(o-iodoaryl)­acrylamides and o-alkynylphenols/o-alkynylanilines with the formation of three C–C bonds and one C–O/C–N bond in a single one-step operation. A wide range of bisheterocycles bearing oxindoles and 3-acylbenzofurans/3-acylindoles were prepared in moderate to excellent yields with good functional group tolerance.

Rh(iii)-catalyzed [4 + 1] cyclization of aryl substituted pyrazoles with cyclopropanols via C–H activation

“…1 Accordingly, the development of efficient and economical ways to synthesize such molecules has attracted continuous interest in organic synthesis. 2 In recent years, transition-metal-catalyzed tandem cyclization reactions through chelation-assisted C–H bond activation have emerged as powerful tools for the step-economical construction of complex cyclic compounds. 3 In particular, tandem cyclization reactions that involve sequential functionalization of C–H and N–H bonds have been demonstrated as a highly efficient strategy to fabricate high-value carbocycles and heterocycles from simple starting materials.…”

Recent advances in palladium‐catalyzed α‐arylation reactions

“…They are more malleable and ductile. Comprising all these properties, this precious gray white metal shows its excellence in many reactions including Wacker process, 19 Heck, 20 Hiyama, 21 Kumada, 22 Negishi, 23 Suzuki, 24 and Stille 25 couplings, hydrosilylations, 26 carbonylation, 27 carbopalladation, 28 synthesis of heterocycles, 29,30 ring formation reactions, 31 formation of C-F bonds, 32 etc. It is also used in automobile catalytic converters.…”