Alcohol Oxidations by Schiff Base Manganese(III) Complexes. Issue 5 (21st January 2020)

• Record Type: Journal Article
• Authors: Neshat, Abdollah; Kakavand, Meysam; Osanlou, Farzane; Mastrorilli, Piero; Schingaro, Emanuela; Mesto, Ernesto; Todisco, Stefano
• Is Part Of: European journal of inorganic chemistry. Issue 5(2020)
• Page Start: 480
• Page End: 490
• Publication Date: 2020-01-21
• Subjects: Oxidation -- Alcohols -- Schiff bases -- Manganese -- Structure elucidation; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201901331
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : Asymmetric Schiff base manganese(III) complexes involving salen ligands, N, N'‐bis(salicylidene)2, 3‐diaminopyridine, N, N'‐bis(3‐methoxysalicylidene)2, 3‐diaminopyridine, N, N'‐bis(3, 5‐di‐ tert ‐butylsalicylidene)2, 3‐diaminopyridine and N, N'‐bis(3, 5‐di‐chloro‐salicylidene)2, 3‐diaminopyridine were prepared and their catalytic activity was investigated in the oxidation of some primary and secondary alcohols. During optimization of oxidation reactions, Mn‐4, bearing electron withdrawing N, N'‐Bis(3, 5‐di‐chloro‐salicylidene)2, 3‐diaminopyridine ligand, showed higher activity than other catalysts tested. The catalytic reactions were carried out in the presence of various oxidants such as oxygen, hydrogen peroxide or tert ‐butyl hydroperoxide (TBHP) and additives such as acetic acid and imidazole. The oxidant/additive combination of TBHP and imidazole was shown to be effective for the oxidation process and the degree of their impact on oxidation reaction was found highly dependent on a balanced ratio between them. Mn‐4 was selected as the most effective catalyst under optimized reaction conditions and revealed efficient for the oxidation of secondary alcohols. Abstract : Air stable manganese(III) catalysts with salen‐type ligands were prepared and applied as catalysts for the oxidation of a variety of primary and secondary alcohols. The Mn catalyst with electron‐withdrawing chloro substituents on the salen ligand was shown to be an efficient catalyst for oxidation reactions in the presence of imidazole and TBHP oxidant.