Synthesis, characterization and crystal structure determination of a new vanadium(IV) Schiff base complex (VOL2) and investigation of its catalytic activity in the epoxidation of cyclooctene

Catalytic potentials of homodioxo-bimetallic dihydrazone complexes of uranium and molybdenum in a homogeneous oxidation of alkenes

“…The increase of the catalyst molar ratio to two double amounts improved the rate of 1,2-cyclooctene oxidation affording good yield of conversion after 4-5 h of the running processes (Table 6, entries 4 and 5; 77, 84, and 62 % with 0.01, 0.02, and 0.04 mmol of 1, respectively). 1a), as observed previously [51,52]. After 4 h of the 1,2-cyclooctene oxidation with catalyst 2, the control conversion reached to the highest values using 0.02 and 0.04 mmol afford 90 and 72 %, respectively (entries 3 and 4).…”

“…The Lewis acidity of the Mo center increases the oxidizing power of the oxo group and the alkene is subsequently oxygenated by nucleophilic attack on an electrophilic oxygen atom of the coordinated H 2 O 2 or TBHP (Scheme 2, III) [53]. The reaction mechanism involves an activation state formed between the complex, oxidant, and alkene (Scheme 2, III) [51,52], affording an activated structural intermediate of the complex, solvent (water from H 2 O 2 or tert-butanol from TBHP) and alkene oxide (Scheme 2, IV) [4,13]. In the catalytic process, in higher conversions, water (from H 2 O 2 ) or tertbutanol (t-BuOH, from TBHP) probably competes with H 2 O 2 or TBHP (Scheme 2, recycling of the catalytic process, I) for coordination to the molybdenum center, forming a less reactive species that leads to the decreasing reaction rate with either H 2 O 2 or TBHP, respectively [51].…”

Efficient epoxidation of cyclododecene and dodecene catalysed by polybenzimidazole supported Mo(VI) complex

“…A wide range of polymer supported Mo(VI) complexes have been successfully applied as catalysts for alkene epoxidation over the last few decades [10][11][12][13][14][15][16][17][18][19]. The application of supported metal complex as a catalyst for a laboratory scale epoxidation could considerably facilitate product work-up and isolation, while on a large scale process, heterogeneous catalyst allow reaction to be run continuously using packed or fluidised bed columns with considerable financial advantages [20][21][22][23][24].…”

Peroxo- and oxovanadium(iv) complexes with tridentate N-heterocycle ligands: synthesis, structure, and catalytic performance

“…4. Unlike the complex 1 and VO(acac) 2 , the TONs of complex 3 were continuously higher than that of VOSO 4 from 1 h to 24 h (as shown in Table 6, entries [3][4][5][6]. These data clearly show that the catalytic activity of complex 1 is far better than that of its starting material VO(acac) 2 , which may be primarily due to the peroxo group and the more number of VQO moiety active centers in one molecular unit of complex 1 than in VO(acac) 2 .…”

“…6 [VOCl 2 {HOCH 2 C(pz) 3 }] showed good catalytic activity (TON = 405) in the Cy oxidation with H 2 O 2 as the oxidant. 6-12 VOL 2 (L = 2-{(E)-[(2-chloroethyl)imino] methyl}-6-methoxy phenol) exhibited high catalytic activity in the epoxidation of cyclooctene with TBHP as the oxidant, wherein 86% conversion was obtained.…”