An efficient and convenient synthesis of various cyclic amidines has been achieved via iridium-catalyzed deoxygenative reduction of lactams with a silane followed by a one-pot cycloaddition reaction with sulfonyl azides. Using the novel tandem procedure, a large array of cyclic amidines bearing various sized rings were synthesized in good yields from readily available lactams. This methodology has been successfully utilized in the late stage diversification of complex architectures bearing a lactam moiety.

Indolizine is an important heterocyclic compound with several interesting properties that make it suitable for numerous applications in many fields, such as biology, medicine and materials. However, the synthesis of 3-alkyl indolizines from bulky primary halogenated alkanes has not yet been reported. Herein, a transition-metal-free synthetic route to 3-aryl and 3-alkyl indolizines from electron-deficient alkenes, pyridines and primary halogenated hydrocarbons has been reported for the first time using a tandem reaction. The key step of this method is the oxidative dehydrogenative aromatization of a tetrahydroindolizine intermediate with 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) as the oxidant. The advantages of this protocol are its use of easily available and low-cost starting materials, the transition-metal-free conditions and its ready scalability.

Considering the ubiquitous nature and ready synthesis of amides, and the great significance of organofluorine‐containing species, the cross‐coupling of amides and polyfluoroarenes, leading to new carbon–carbon bond‐forming methodologies, would find useful applications in synthesis, late‐stage functionalization, and rapid generation of molecular diversity. Herein, we present a novel synthesis of α‐polyfluoroaryl amines via Sm/SmI2‐mediated deoxygenative cross‐coupling of aromatic amides with polyfluoroarenes through direct C−H functionalization. The structural and functional diversity of these readily available precursors provides a versatile and flexible strategy for the streamlined synthesis of α‐polyfluoroaryl amines. Combining experimental and theoretical studies, a novel plausible mechanism of the α‐aminocarbene‐mediated C−H insertion has been revealed, which may stimulate future work for the development of novel methods in amine synthesis.