Studies on Regioselectivity of Nitration of Coumarins with Cerium(IV) Ammonium Nitrate: Solid-State Nitration of 6-Hydroxy-Coumarins on Montmorillonite K-10 Clay Support Under Microwave Irradiation
作者:Nemai C. Ganguly、Mrityunjoy Datta、Prithwiraj De、Romaprosad Chakravarty
DOI:10.1081/scc-120015821
日期:2003.1.4
in acetic acid and acetonitrile in acceptable-to-excellent yields. Acetonitrile was found to be a better solvent for regioselective nitration than acetic acid. Use of CAN on montmorilloniteK-10 clay under microwaveirradiation for expeditious solvent-free regioselective nitration has been revealed for the first time.
A novel methodology for the efficient and selective nitration of coumarins has been developed. The reaction of coumarins containing a hydroxy group with nitric oxide in CH2Cl2 or CH3CN gave aromatic mono- and regio-specific-nitrated coumarins in various yields.
Synthesis of Fused Oxazolocoumarins from <i>o</i>
-Hydroxynitrocoumarins and Benzyl Alcohol Under Gold Nanoparticles or FeCl<sub>3</sub>
Catalysis
作者:Evangelia-Eirini N. Vlachou、Gerasimos S. Armatas、Konstantinos E. Litinas
DOI:10.1002/jhet.2842
日期:2017.7
Synthesis of fused oxazolocoumarins has been achieved from the one‐pot tandem reactions of o‐hydroxynitrocoumarins with benzyl alcohol in toluene undercatalysis in a sealed tube at 150°C. The catalysis was performed by gold nanoparticles supported on TiO2 (0.4 mol% Au) or FeCl3 (5%) or silver nanoparticles supported on TiO2 (1.7 mol% Ag).