Synthesis of a new series of Ni(ii), Cu(ii), Co(ii) and Pd(ii) complexes with an ONS donor Schiff base: crystal structure, DFT study and catalytic investigation of palladium and nickel complexes towards deacylative sulfenylation of active methylenes and regioselective 3-sulfenylation of indoles via thiouronium salt formation

A series of Ni(ii), Cu(ii), Co(ii), and Pd(ii) complexes have been synthesized with a chelating Schiff base ligand coordinated to a metal center with ONS donor atoms. The ligand and complexes are characterized by elemental analysis and spectroscopic techniques like FT-IR, 1H-NMR, and UV-Visible spec...

Full description

Saved in:
Bibliographic Details
Published in:Dalton transactions : an international journal of inorganic chemistry 2018, Vol.47 (13), p.4583-4595
Main Authors: Devi, Namita, Sarma, Kuladip, Rahaman, Rajjakfur, Barman, Pranjit
Format: Article
Language:English
Subjects:
Aromatic compounds
Catalysis
Catalysts
Charge distribution
Chelation
Chemical synthesis
Cobalt
Coordination compounds
Copper
Cross coupling
Crystal structure
Diketones
Electronic structure
Fourier transforms
Halides
Imines
Indoles
Infrared radiation
Ketones
Ligands
Nickel
Regioselectivity
Single crystals
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A series of Ni(ii), Cu(ii), Co(ii), and Pd(ii) complexes have been synthesized with a chelating Schiff base ligand coordinated to a metal center with ONS donor atoms. The ligand and complexes are characterized by elemental analysis and spectroscopic techniques like FT-IR, 1H-NMR, and UV-Visible spectroscopy. The single crystal structure of the Pd(ii) complex is obtained by X-ray diffraction analysis and exhibits slightly distorted square planar geometry. The structure is optimized by DFT, TD-DFT calculation to elaborate the electronic structure and NBO for the charge distribution analysis of the Pd(ii) complex. The synthesized Pd(ii) and Ni(ii) complexes as catalysts have been investigated in the C-S cross-coupling of indoles and active methylenes. The metal propelled regioselective transformation afforded 3-sulfenylated indoles while β-diketones favored deacylated monosulfenyl ketones in an excellent yield via thiouronium salt formation. The Pd(ii) complex displays slightly better reactivity whereas the Ni(ii) complex is cost-efficient. The method is fast, easy to handle and cost effective in terms of high reactivity of catalysts, use of non-toxic solvents, and cheaper aryl halides and thiourea replace conventional sulfur sources, providing a practical access to organic transformations.
ISSN:1477-9226
1477-9234
DOI:10.1039/c7dt04635a