Direct C-C coupling of indoles with alkylamides via oxidative C-H functionalization using Fe3O(BDC)3 as a productive heterogeneous catalyst

A metal-organic framework Fe3O(BDC)(3) was prepared, and used a recyclable heterogeneous catalyst for the direct C-C coupling of indoles with alkylamides via oxidative C-H functionalization. The catalyst expressed higher catalytic efficiency for the direct C-C coupling transformation than that of other MOFs and that of other homogeneous iron catalysts. The coupling of indoles with alkylamides could only continued to form indole derivatives in the presence of the solid framework catalyst, and the donation of leached active iron species, if any, was trivial. The Fe-MOF catalyst could be reused many times for the synthesis of indole derivatives via the direct C-C coupling without a substantial deterioration in catalytic activity. To the best of our knowledge, this direct C-C coupling transformation was not previously accomplished using solid catalysts. (C) 2016 Elsevier B.V. All rights reserved.