Effect of N-based additive on the optimization of liquid phase oxidation of bicyclic, cyclic and aromatic alcohols catalyzed by dioxidomolybdenum(vi) and oxidoperoxidomolybdenum(vi) complexes. Issue 122 (24th November 2015)

• Record Type: Journal Article
• Authors: Maurya, Mannar R.; Saini, Neeraj; Avecilla, Fernando
• Is Part Of: RSC advances. Volume 5:Issue 122(2015)
• Page Start: 101076
• Page End: 101088
• Publication Date: 2015-11-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra16490g
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Catalytic potentials of [Mo VI O2 ] 2+ and [Mo VI O(O2 )] 2+ complexes with dibasic tridentate ONO donor ligands for the oxidation of bicyclic, cyclic and aromatic alcohols in the presence of NEt3 are reported. Abstract : Two dioxidomolybdenum(vi ) complexes, [Mo VI O2 (L 1 )(MeOH)] (1 ) and [Mo VI O2 (L 2 )(MeOH)] (2 ) and their corresponding oxidoperoxidomolybdenum(vi ) complexes, [Mo VI O(O2 )(L 1 )(MeOH)] (3 ) and [Mo VI O(O2 )(L 2 )(MeOH)] (4 ) with ONO tridentate ligands, 4-[3, 5-bis(2-hydroxyphenyl)-1, 2, 4-triazol-1-yl]benzoic acid (H2 L 1, I ) and 3, 5-bis(2-hydroxyphenyl)-1-phenyl-1, 2, 4-triazole (H2 L 2, II ) have been synthesized and characterized by elemental analysis, spectroscopic techniques (infrared, UV-Vis, 1 H and 13 C NMR) and thermogravimetric analysis. Structures of1a (DMSO coordinated) and2 (methanol coordinated) confirmed by single crystal X-ray study reveal that the tridentate ligands bind to the metal center through two oxygen atoms and a ring nitrogen atom. These complexes have been tested as catalysts for the homogeneous oxidation of bicyclic (isoborneol and fenchyl alcohol), aromatic (benzyl alcohol and cumic alcohol) and cyclic (cyclohexanol) alcohols, using 30% H2 O2 as an oxidant. Various parameters such as amounts of catalyst, oxidant, solvent and temperature of the reaction mixture have been taken into consideration for the maximum conversion of substrates. Effect of N-based additive (NEt3 ) on the conversion of substrates as well as selectivity of the corresponding product(s) under the optimized reaction conditions has also been checked and obtained results suggest that addition of an additive reduces time to achieve equilibrium and increases conversion of alcohols.