Palladium(II) complexes with diaminomaleonitrile-based Schiff-base ligands: Synthesis, characterization and application as Suzuki–Miyaura coupling catalysts

Diaminomaleonitrile derivatives as new potential antichagasic compounds: a study of structure-activity relationships

Background: Schiff bases are synthetically accessible compounds that have been used in medicinal chemistry. Methods & results: In this work, 27 Schiff bases derived from diaminomaleonitrile were synthesized in high yields (80-98%). Molecular docking studies suggested that the Schiff bases interact with the catalytic site of cruzain. The most active cruzain inhibitor, analog 13 (IC₅₀ = 263 nM), was predicted to form an additional hydrophobic contact with Met68 in the binding site of the enzyme. A strong correlation between the IC₅₀ values and ChemScore binding energies was observed (R = 0.99). Kernel-based 2D quantitative structure-activity relationship models for the whole dataset yielded sound correlation coefficients (R² = 0.844; Q² = 0.719). Conclusion: These novel and potent cruzain inhibitors are worthwhile starting points in further Chagas disease drug discovery programs.

Palladium(ii) complexes of tetradentate donor–acceptor Schiff base ligands: synthesis and spectral, structural, thermal and NLO properties

Structural and NLO behavior of push–pull palladium(ii) complexes of metallocenyl-containing asymmetric Schiff base ligands.

Pd(CH3CN)2Cl2/Pipecolinic Acid as a Highly Efficient Catalytic System for Suzuki-Miyaura Cross-coupling Reaction of Bromoaryl Carboxylic Acids in Water

In this study, a convenient and highly efficient catalytic system for the Suzuki-Miyaura coupling reaction was investigated under mild conditions. A combination of Pd(CH3CN)2Cl2 and pipecolinic acid showed excellent catalytic performance and afforded high turnover numbers; turnover numbers were up to 4.9 × 105 for the coupling reaction of 4-bromobenzoic acid and tetraphenylboron sodium. The catalytic system was also effective for the indexes of 4-bromobenzoic acid, and high turnover numbers were obtained.

Palladium-Schiff Base Complexes Encapsulated in Zeolite-Y Host: Functionality Controlled by the Structure of a Guest Complex

A series of palladium complexes of tetradendate Schiff base ligands L1 ( N,N'-bis(salicylidene)phenylene-1,3-diamine) and its derivatives L2 and L3 have been synthesized by using the "flexible ligand method" within the supercage of zeolite-Y. These complexes in both their free and encapsulated states have been thoroughly characterized with the help of different characterization tools such as XRD, SEM-EDS, BET, thermal analysis, XPS, IR, and UV-vis spectroscopic studies. All these encapsulated complexes are identified with a dramatic red shift of the d-d transition in their electronic spectra when compared with their free states. Theoretical as well as experimental studies together suggest a substantial modification of the structural parameters of square planar Pd(II)-Schiff base complexes upon encapsulation within the supercage of zeolite-Y. Encapsulated complexes are also subject to show modified catalytic activities toward the Heck reaction. These heterogeneous catalysts can easily be separated from the reaction mixture and reused.