Related Experiment Video
Updated: Sep 27, 2026

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
Synthesis, Characterization, and Catalytic Activity of a β-Benzimidazole-Bridged Binuclear Oxo-Vanadyl(IV)
Sumit Kumar Yadav1, Shivani Rathi1, Muniappan Sankar1
1Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, India.
Abstract:
A binuclear oxo-vanadyl(IV) porphyrin (V2OBP), in which two vanadium(IV) porphyrin macrocycles are connected via benzimidazole groups at the β-position, has been synthesized and characterized using a variety of techniques, including UV-vis spectroscopy, FT-IR, EPR, cyclic voltammetry (CV), density functional theory (DFT) calculations, and mass spectrometry. The catalytic properties of binuclear oxo-vanadyl(IV) porphyrin (V2OBP) were further examined in a one-pot multicomponent Biginelli reaction, resulting in the production of biologically active 3,4-dihydropyrimidin-2-(1H)-one (DHPM) derivatives and their corresponding thiones, all under solvent-free conditions. Its catalytic performance was compared to that of VOP. Various reaction parameters, such as catalyst amount, time, solvent, and temperature, were optimized to maximize the DHPM and thione yields. The β-functionalized V2OBP dimer showed significantly higher conversion rates (86%-97% yield) of DHPMs and thiones under optimized conditions, with high turnover numbers (TON, 7056-8528) and turnover frequencies (TOF, 3024-3411 h- 1), outperforming values reported in the literature. Additionally, the catalyst demonstrated excellent recyclability, remaining effective for up to seven cycles.
Related Concept Videos
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Reactions at the Benzylic Position: Oxidation and Reduction
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Reactions of Aldehydes and Ketones: Baeyer–Villiger Oxidation
The carbonyl center is activated by...
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
