Direct 2-Amination of Pyridines via Dearomatization/Rearomatization Strategy.

2-Aminopyridines are privileged scaffolds in pharmaceuticals, yet direct amination from pyridines remains scarce. We have developed a metal-free dearomatization/rearomatization strategy using readily available isocyanates as nitrogen source. Inexpensive DMAD serves as the dearomative reagent to form intermediates, which are rearomatized by DBU to afford 2-aminopyridines. The protocol offers good functional-group tolerance, operational simplicity, and scalability. It extends to quinolines and isoquinolines, and allows late-stage functionalization of complex biomolecules.