Triazine functionalized ordered mesoporous organosilica as a novel organocatalyst for the facile one-pot synthesis of 2-amino-4H-chromenes under solvent-free conditions
A highly ordered 2D-hexagonal mesoporous material functionalized with a triazine moiety has been synthesized via post-synthetic modification of mesoporous SBA-15 with thiols followed by a thiol–ene click reaction using 2,4,6-triallyloxy-1,3,5-triazine. A facile one-pot three-component condensation reaction of aromatic aldehyde, malononitrile and activated phenols for the synthesis of a diverse range of 2-amino-4H-chromenes has been efficiently catalyzed over this novel mesoporous metal-free heterogeneous organocatalyst under solvent-free reaction conditions. Further, this organocatalytic reaction is waste-free, easy to work-up and efficiently reused. The organic products have been isolated from the reaction mixture by using easily disposable solvents and can be easily purified by re-crystallization.