Wang J, Ma J, Li X, Li Y, Zhang G, Zhang F, Fan X * Tianjin University, P. R. of China
Cu
2O Mesoporous Spheres with a High Internal Diffusion Capacity and Improved Catalytic
Ability for the aza-Henry Reaction Driven by Visible Light.
Chem. Commun. 2014;
50: 14237-14240
Key words
mesoporous copper(I) oxide - photocatalytic aza-Henry reaction - visible light - oxygen
Significance
Mesoporous copper(I) oxide spheres with different pore sizes (5 nm for SP-Cu2O and 15 nm for LP-Cu2O) were prepared and applied to the visible-light-promoted aza-Henry reaction. The
reaction of N-aryl tetrahydroisoquinolines 1 with nitroalkanes 2 was carried out in the presence of LP-Cu2O and molecular oxygen under the irradiation of blue LEDs to afford the corresponding
coupling products 3 in 83–90% yield. The reaction without catalyst gave 3a in only 5% yield under otherwise similar conditions.
Comment
The catalysts were characterized by SEM, TEM, XRD, and N2 adsorption–desorption analyses. For the formation of 3a, LP-Cu2O was recovered by centrifugation and reused four times without significant loss of
catalytic activity. SEM observation of LP-Cu2O after the fifth run showed no change of its morphology. The preparation of mesoporous
Cu2O spheres with small pore size was previously reported by Shang, Zhang and Guo (J. Mater. Chem. 2012, 22, 856).
