Kaolin/KOH Is an Efficient Heterogeneous Catalyst for the Synthesis of 3-Hydroxy-3-indolyl Oxindoles
作者:G. Srihari、M. Marthanda Murthy
DOI:10.1080/00397911.2010.515342
日期:2011.9.15
3-Hydroxy-3-indolyl oxindoles were synthesized from isatins and indoles in good to excellent yields by using heterogeneous catalyst kaolin preloaded with KOH.
Synthesis of 3-ethynyl-3-hydroxy-2-oxindoles and 3-hydroxy-3-(indol-3-yl) indolin-2-ones using CuWO4 nanoparticles as recyclable heterogeneous catalyst in aqueous medium
acetylenes (spC-H activation) and selective synthesis of 3-hydroxy-3-(indol-3-yl) indolin-2-ones and 3,3′-bis(indolyl)indolin-2-ones (via Friedel-Crafts alkylation reaction) is reported in presence of CuWO4 (10 mol%) nanoparticles in aqueous medium. The catalyst was regenerated and reused up to 6 cycles without losing catalytic activity. This is the first report for the spC-H activation using CuWO4