A Polyniobotungstate-Based Hybrid for Visible-Light-Induced Phosphorylation of <i>N</i>-Aryl-Tetrahydroisoquinoline
Fan Gao, Wanru Xiao, Shujun Li, Bing Yu
Abstract
A new organic–inorganic hybrid based on a Nb/W mixed-addendum polyoxometalate with the formula H14[(Co(H2O)3)2(C10H8N2)4(P4W30Nb6O123)]·4(C10H8N2)·8H2O (Co-POM) has been synthesized by the solvothermal method and characterized by single-crystal X-ray diffraction (XRD), powder X-ray diffraction (PXRD), elemental analysis, FTIR spectroscopy, UV–vis absorption spectrum, and thermogravimetric analysis (TGA). Importantly, visible-light-absorption peaks around 525 nm for Co-POM indicated that this material should have potential in visible-light-induced organic reactions. Herein, we disclosed visible-light-promoted phosphorylation of N-aryl-tetrahydroisoquinoline using Co-POM as an efficient heterogeneous photocatalyst. In this procedure, diverse phosphorus reagents are compatible at room temperature and in an O2 atmosphere, giving the corresponding products in good to excellent yields (up to 97%). Simultaneously, this heterogeneous photocatalyst can be recycled up to ten times with a negligible decrease in yield, showing outstanding sustainability and recyclability.