Development of catalytic C-C and C-N bond forming reactions via rhodium mediated C-H bond activation

Abstract

Part 1. A Versatile Rh(I) Catalyst System Enabling the Addition of Heteroarenes to both Alkenes and Alkynes via C-H Bond Activation Pathway

A highly efficient and convenient rhodium catalyst system was developed for the direct hydroheteroarylation of unsatuated compounds with heteroarenes. A base cocatalyst was found to facilitate the key arene C-H bond activation step which is believed to proceed via a base-assisted pathway. Substrate scope was very broad to include both electron-deficient pyridine N-oxides and electron-rich azoles. The identical catalytic system was successfully applied to the hydroheteroarylation of both alkenes and alkynes with excellent regio- and stereoselectivity.

Part 2. Rhodium-Catalyzed Direct C-H Amination of Benzamides with Aryl Azides: A Novel Synthetic Route to Diarylamines

Direct amination of arene using aryl azides was developed for yielding structurally interesting diarylamine derivatives which have versatile synthetic and medicinal utilities. This can be the first example of rhodium catalyzed direct amination method for delivering anilino group into (hetero)arenes. A range of arene substrates were selectively aminated in high yields with excellent functional group tolerance. The amination requires no external oxidants releasing N2 as the single by-product, thus offering an environmentally benign procedure.