Palladium-Catalyzed C(sp2)–H Pyridocarbonylation of N-Aryl-2-aminopyridines: Dual Function of the Pyridyl Moiety
摘要:
An efficient synthesis of 11H-pyrido[2,1-b]-quinazolin-11-one through palladium-catalyzed C(sp(2))-H pyridocarbonylation of N-aryl-2-aminopyridines has been developed. The pyridyl group acts as an intramolecular nucleophile for the first time in C-H carbonylation reactions.
The catalytic conditions of copper(I) iodide/potassium carbonate/ TRANS- N, N′-dimethylcyclohexane-1,2-diamine, either in toluene at reflux temperature, or by heating neat at 150 °C effectively promoted the C-N coupling of aryl bromides with cyclic ureas. By employing a protection-deprotection strategy, unsymmetrical diaryl-substituted cyclic ureas could also be synthesized.