Solvent‐Free Organocatalytic Synthesis of Fluorescent N‐Alkylated Pyridones: A Metal/Base‐Free Migration Strategy

A solvent‐, transition‐metal‐, and base‐free organocatalytic system (Ph 3 CBr or TMSI) enables efficient O‐ to N‐migration for N‐alkylated pyridone synthesis. Critically, gram‐scale production of a cinnamyl‐derived product (4.73 mmol) completes within 3 h at 100°C without yield erosion. Stereospecific [1,3]‐rearrangements predominantly preserve alkene geometry, while resultant pyridones exhibit tunable fluorescence (Φ up to 0.39 in chloroform). This protocol establishes an eco‐compatible, directly amplifiable platform toward functional heterocycles.