Sustainable Synthetic Approach for (Pyrazol-4-ylidene)pyridines By Metal Catalyst-Free Aerobic C(sp2)-C(sp3) Coupling Reactions between 1-Amino-2-imino-pyridines and 1-Aryl-5-pyrazolones

Hamada Mohamed Ibrahim; Haider Behbehani

doi:10.1021/acsomega.9b01650

Sustainable Synthetic Approach for (Pyrazol-4-ylidene)pyridines By Metal Catalyst-Free Aerobic C(sp²)-C(sp³) Coupling Reactions between 1-Amino-2-imino-pyridines and 1-Aryl-5-pyrazolones

ACS Omega. 2019 Jul 5;4(7):11701-11711. doi: 10.1021/acsomega.9b01650. eCollection 2019 Jul 31.

Authors

Hamada Mohamed Ibrahim^{1

2}, Haider Behbehani¹

Affiliations

¹ Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait.
² Chemistry Department, Faculty of Science, Fayoum University, P.O. Box 63514, Fayoum, Egypt.

Abstract

A novel, metal catalyst-free, and efficient method has been developed for the synthesis of (pyrazol-4-ylidene)pyridine derivatives. The process involves dehydrogenative coupling of 1-amino-2-imino-pyridines with 1-aryl-5-pyrazolone derivatives utilizing O₂ as the sole oxidant. The new method benefits from a high atom economy, efficiency, and substrate scope, as well as the simplicity of reaction and product purification procedures.