Palladium-Catalyzed C–H Bond Arylation and O- to N-Alkyl Migratory Rearrangement of 2-Alkoxythiazoles: One-Pot Access to 2-Alkoxy-5-arylthiazoles or 3-Alkyl-5-arylthiazol-2(3H)-ones

Abstract Pd-catalyzed direct arylation of 2-alkylthiazoles is a well-known reaction affording the corresponding 2-alkyl-5-arylthiazoles in very high yields. Conversely, reactivity 2-alkoxythiazoles has not been described yet. Herein, we report conditions for regioselective C5-arylation 2-alkoxythiazoles. Moreover, also found leading to 3-alkyl-5-arylthiazol-2(3H)-ones via one-pot with an O- N-alkyl migratory rearrangement. The judicious choice temperature and time allows control over selectivity reaction. In general, at 100 °C, 2-alkoxy-5-arylthiazoles were major products, whereas, 120 °C longer time, obtained good selectivities. promoted by ligand-free air-stable palladium catalyst simple inexpensive base, without oxidant or further additives, tolerates variety useful substituents on aryl bromide heteroaryl bromides.