Iron-catalyzed C(sp3)–H functionalization of methyl azaarenes: a green approach to azaarene-substituted α- or β-hydroxy carboxylic derivatives and 2-alkenylazaarenes
A highly efficient synthesis of azaarene-substituted 3-hydroxy-2-oxindoles in catalyst-free conditions is described by the reaction of 2-methyl pyridines with isatins under microwave irradiation in aqueous medium. Simple reaction conditions, high yields of the products and environmentally benign medium are attractive features of the present protocol.
3-(Pyridylmethyl)-3-hydroxy-2-oxindole derivatives were synthesized in high yields under mild, and catalyst-free conditions using polyethylene glycol (PEG-400) as a solvent. The use of low cost PEG-400 makes it simple, convenient, and environmentally benign. (c) 2013 Elsevier Ltd. All rights reserved.