Synthesis of Nitrogen-Containing Heterocycles via Imidoyl or Iminyl Radical Intermediates

Synthesis of nitrogen-containing heterocycles with isocyanides, isothiocyanates, nitriles, imines, oxime derivatives, and other related compounds has been deeply investigated in organic synthesis. This chapter mainly focuses on summarizing radical cyclization reactions of these C-N unsaturated precursors to afford N-heterocycles in the past decade as well as some earlier feature examples. In most cases, imidoyl or iminyl radicals are involved in cyclizing onto unsaturated systems or heteroatoms to generate N-heterocycles, such as phenanthridines, (iso)quinolines, pyridines, indoles, and pyrroles. A few examples via other types of radical intermediates starting from isothiocyanates, isocyanates, and analogous structures are also included.