Copper-Catalyzed Radical Methylation/C–H Amination/Oxidation Cascade for the Synthesis of Quinazolinones
摘要:
A copper-catalyzed radical methylation/sp(3) C-H amination/oxidation reaction for the facile synthesis of quinazolinone was developed. In this cascade reaction, dicumyl peroxide acts not only as a useful oxidant but also as an efficient methyl source. Notably, a methyl radical, generated. from peroxide, was confirmed by electron paramagnetic resonance for the first time.
Nafion-H: An Efficient and Recyclable Heterogeneous Catalyst for the One-Pot Synthesis of 2,3-Disubstituted 4-(3<i>H</i>)-Quinazolinones under Solvent-Free Microwave Irradiation Conditions
A one-pot synthesis of 2,3-disubstituted 4-(3H)-quinazolinones has been carried out efficiently by the three-component coupling of isatoic anhydride/anthranilic acid, orthoesters, and amines in the presence of Nafion-H (a perfluorinated resin-supported sulfonic acid) as a heterogeneous catalyst. The reaction occurred within a few minutes under solvent-free microwave irradiation conditions to afford