Removable bidentate directing group assisted-recyclable metal-organic frameworks-catalyzed direct oxidative amination of Sp2 C-H bonds

Several Cu-MOFs were showed to be efficient heterogeneous catalysts for ortho-amination of benzoic acid derivative C-H bonds by N-H amines using 8-aminoquinoline as bidentate directing group. The optimal reaction conditions involve the use of Cu-MOFs (25%), N-methylmorpholine oxide (NMO) as an oxidant, secondary or primary amine coupling partner, DMF, DMA, or NMP solvent at 90-100 degrees C. Furthermore, the Cu-MOFs catalyst could be facilely isolated from the reaction mixture and reused several times without remarkable degradation in catalytic reactivity. Contribution from homogeneous leached active copper species, if any, is negligible. To the best of our knowledge, C-H activation reactions using bidentate directing groups, which are increasingly gaining importance, under heterogeneous catalytic systems were not previously mentioned in the literature. (C) 2014 Elsevier Inc. All rights reserved.