Development of New Thiazole Complexes as Powerful Catalysts for Synthesis of Pyrazole-4-Carbonitrile Derivatives under Ultrasonic Irradiation Condition Supported by DFT Studies

Mahmoud Abd El Aleem Ali Ali El-Remaily; Tarek El-Dabea; Mohammed Alsawat; Mohamed H H Mahmoud; Alia Abdulaziz Alfi; Nashwa El-Metwaly; Ahmed M Abu-Dief

doi:10.1021/acsomega.1c02811

Development of New Thiazole Complexes as Powerful Catalysts for Synthesis of Pyrazole-4-Carbonitrile Derivatives under Ultrasonic Irradiation Condition Supported by DFT Studies

ACS Omega. 2021 Aug 8;6(32):21071-21086. doi: 10.1021/acsomega.1c02811. eCollection 2021 Aug 17.

Authors

Mahmoud Abd El Aleem Ali Ali El-Remaily¹, Tarek El-Dabea¹, Mohammed Alsawat², Mohamed H H Mahmoud², Alia Abdulaziz Alfi³, Nashwa El-Metwaly^{3

4}, Ahmed M Abu-Dief^{1

5}

Affiliations

¹ Department of Chemistry, Faculty of Science, Sohag University, 82524 Sohag, Egypt.
² Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
³ Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University, 715, Makkah, Saudi Arabia.
⁴ Department of Chemistry, Faculty of Science, Mansoura University, 35516, Mansoura, Egypt.
⁵ Department of Chemistry, College of Science, Taibah University, P.O. Box 344, 344, Madinah, Saudi Arabia.

Abstract

In this study, we are interested in preparing Fe(III), Pd(II), and Cu(II) complexes from new thiazole derivatives. All syntheses were elaborately elucidated to estimate their molecular and structural formulae, which agreed with those of mononuclear complexes. The square-planer geometry of Pd(II) complex (MATYPd) was the starting point for its use as a heterocatalyst in preparing pyrazole-4-carbonitrile derivatives 4a-o using ultrasonic irradiation through a facile one-pot reaction. The simple operation, short-time reaction (20 min), and high efficiency (97%) were the special advantages of this protocol. Furthermore, this green synthesis strategy was advanced by examination of the reusability of the catalyst in four consecutive cycles without significant loss of catalytic activity. The new synthesis strategy presented remarkable advantages in terms of safety, simplicity, stability, mild conditions, short reaction time, excellent yields, and use of a H₂O solvent. This catalytic protocol was confirmed by the density functional theory (DFT) study, which reflected the specific characteristics of such a complex. Logical mechanisms have been suggested for the successfully exerted essential physical parameters that confirmed the superiority of the Pd(II) complex in the catalytic role. Optical band gap, electrophilicity, and electronegativity features, which are essential parameters for the catalytic behavior of the Pd(II) complex, are based mainly on the unsaturated valence shell of Pd(II).