Well Defined Phosphine Free Ni-Catalyzed Dehydrogenation of Secondary Alcohols for the Synthesis of Ketones and Ketazines.

In this work, we unveil a novel synthesis of bench stable Ni (II) complexes supported by tetradentate Schiff-base ligands and the complexes were devoid of any phosphine or phosphine-based ligand. These Ni-complexes were successfully applied for the dehydrogenation of secondary alcohols for ketone and ketazine syntheses. Secondary alcohols with different functional groups were well tolerated during catalytic cycle.

One-Pot Synthesis of 1, 2-Dihydro [1,2,4] Triazinium Salt by Copper-Assisted Unprecedented Cyclization Reaction: Applications in DNA and Protein Interaction Studies.

Copper catalyzed intramolecular annulation of 2-((2-benzylidene-1-phenylhydrazineyl)methyl)pyridine derivatives was described. It was found that Cu(II) is reduced under the reaction condition to Cu(I). Synthesized 1,2-dihydro [1,2,4] triazinium salt showed fluorescence activity in the solid state.

Methyl Formate, an Alternative Transfer Hydrogenating Agent for Chemoselective Reduction of -Heteroarenes and Azoarenes.

The search for efficient molecular hydrogen precursors and their catalytic exploration is necessary for the evolution of catalytic transfer hydrogenation. Methyl formate (MF) having high hydrogen content still remains unexplored for such transformations. Herein, we disclosed a bifunctional Ir(III)-complex catalyzed chemoselective TH protocol for -heteroarenes and azoarenes using MF.

Crystal structure of a phenoxyl radical complex relevant to the metal site of the galactose oxidase enzyme: A facile one-pot synthesis, evidence for hydrogen atom transfer and DNA cleavage self-activation.

Copper complexes [Cu(LH)ClO] (1) and [Cu(L)NO] (2), which are relevant to the metal site of the galactose oxidase enzyme, were synthesized and characterized by different spectroscopic methods. LH and LH [where LH stands for 2,2'-((1,1')(2,2'-(pyridine-2,6-diyl)bis(2-phenylhydrazin-2-yl-1-ylidene))bis(methanylylidene))diphenol and LH stands for 6,6'-((1,1')-(2,2'-(pyridine-2,6-diyl)bis(2-phenylhydrazin-2-yl-1-ylidene))bis(methanylylidene))bis(2,4-di--butylphenol), H stands for dissociable proton] are pentadentate ligands. These ligands provide pyridyl N, two imine N, and two non-innocent phenoxyl and phenolato O donors, forming complex 1 as a non-radical complex, while complex 2 is a phenoxyl radical complex.

Design and synthesis of novel palladium cyclometallate-based fluorescent probe: Studies on interaction with cell membrane by confocal and fluorescence lifetime imaging.

Coordination complexes offer great potential as cellular imaging probes, which allow to examine specific cell organelle structures in their physiological conditions to better understand the biological system. Understanding the heterogeneous nature of the cell membrane could unveil details of their functionality. Here, we have developed a new anthracene conjugated fluorescent palladium(II) cyclometallate [PdLCl] where LH = [2-(2- (anthracen-9-ylmethylene)-1-phenylhydrazineyl)pyridine] (H stands for dissociable proton), which not only specifically stains the cell membrane, but could be utilized to visualise the membrane by the confocal and fluorescence lifetime imaging microscopy (FLIM).

Well-Defined Phosphine-Free Manganese(II)-Complex-Catalyzed Synthesis of Quinolines, Pyrroles, and Pyridines.

Herein, we report a simple, phosphine-free, and inexpensive catalytic system based on a manganese(II) complex for synthesizing different important N-heterocycles such as quinolines, pyrroles, and pyridines from amino alcohols and ketones. Several control experiments, kinetic studies, and DFT calculations were carried out to support the plausible reaction mechanism. We also detected two potential intermediates in the catalytic cycle using ESI-MS analysis.

Designed pincer ligand supported Co(II)-based catalysts for dehydrogenative activation of alcohols: Studies on -alkylation of amines, α-alkylation of ketones and synthesis of quinolines.

Base-metal catalysts Co1, Co2 and Co3 were synthesized from designed pincer ligands L1, L2 and L3 having NNN donor atoms respectively. Co1, Co2 and Co3 were characterized by IR, UV-Vis. and ESI-MS spectroscopic studies.

Ferrocenyl palladacycles derived from unsymmetrical pincer-type ligands: evidence of Pd(0) nanoparticle generation during the Suzuki-Miyaura reaction and applications in the direct arylation of thiazoles and isoxazoles.

A new family of ferrocenyl-palladacycle complexes Pd(L)Cl (Pd1) and Pd(L)Cl (Pd2) were synthesized and characterized by UV-visible, IR, ESI-MS, and NMR spectral studies. The molecular structures of Pd1 and Pd2 were determined by X-ray crystallographic studies. Palladacycle catalyzed Suzuki-Miyaura cross-coupling reactions were investigated utilizing the derivatives of phenylboronic acids and substituted chlorobenzenes.