Metal-Free Sequential Amidation and Intramolecular C_(sp2~-)H Direct Amination of Coumarin-3-carboxylic Acids under Ambient Conditions:Scope and Mechanistic Insights

摘要

A metal-free sequential amidation and intramolecular direct C_(sp2~-)H amination of coumarin-3-carboxylic acids has been achieved under ambient conditions,resulting in a new series of biologically interesting chromenopyridopyrimidine-derived polyfunctional heterocycles.The DFT study offers mechanistic insights into this transformation.The salient features of this efficient and practical method are operational simplicity,metalfree synthesis,one-pot sequential amidation and amination,mild reaction conditions,good to excellent yields,and gramscale synthetic applicability.