Commercial Zinc Oxide: A Facile, Efficient, and Eco-friendly Catalyst for the One-Pot Three-Component Synthesis of Multisubstituted 2‑Aminothiophenes via the Gewald Reaction
journal contributionposted on 20.02.2016 by Reza Tayebee, S. Javad Ahmadi, Esmaeil Rezaei Seresht, Farzad Javadi, Mohammad A. Yasemi, Morteza Hosseinpour, Behrouz Maleki
Any type of content formally published in an academic journal, usually following a peer-review process.
An eco-friendly, simple, and effective protocol is developed for the synthesis of various multisubstituted 2-aminothiophenes. In the presence of a catalytic amount of ZnO (5 mol %), ketones or aldehydes, malononitrile and elemental sulfur were converted to the corresponding 2-aminothiophene derivatives in moderate to high yields (27%–70%) under solvent-free conditions at 100 °C. Zinc oxide as an efficient, readily available, and reusable catalyst, showed very good catalytic activity for the synthesis of 2-aminothiophene derivatives. Thus far, little research has been reported on the Gewald reaction under solvent-free conditions; to the best of our knowledge, this is the first time that it has been proposed as an inexpensive and readily available catalyst for use in the target synthetic route.