Ullmann Coupling Reaction of Nitro-Substituted Aryl Halides with Phenols under Mild Conditions: Micro-/Mesoporous Hierarchical LaAlPO-5 Zeolite Catalyst

Graphical Zeolite my fire : Ullmann coupling reactions of phenols with nitro-substituted aryl halides are catalyzed by rare-earth-doped mesoporous AlPO-5 zeolites in the absence of ligands. The LaAlPO-5-MAlPO-5-M zeolite is an excellent catalyst for Ullmann coupling reactions of phenols and nitro-substituted aryl halides. Mesoporous LaAlPO-5 has an excellent stability and recyclability in the Ullmann coupling of p -X-nitrobenzene (X=Cl, Br, and I) with 2-naphthol. Heterogeneous catalytic reactions of aromatic organic molecules over zeolite catalysts present many challenges because of the shape selectivity of the micropores of conventional zeolites that limits the diffusion of aromatic molecules. Herein, Ullmann coupling reactions of phenols with nitro-substituted aryl halides were catalyzed by rare-earth-doped mesoporous AlPO-5 zeolites in the absence of ligands. The AlPO-5-MAlPO-5-M zeolites had a pure AFI structure and consisted of spherical particles assembled by nanofibers. The rare-earth elements were highly dispersed in the AlPO-5-MAlPO-5-M samples. The LaAlPO-5-MAlPO-5-M zeolite is an excellent catalyst for Ullmann coupling reactions of phenols and nitro-substituted aryl halides. Mesoporous LaAlPO-5 has an excellent stability and recyclability in the Ullmann coupling of p -X-nitrobenzene (X=Cl, Br, and I) with 2-naphthol. These results are important in the exploration of attractive Ullmann coupling reactions and in the development of mesoporous zeolite catalysts for other organic reactions.