Efficient Ru-Catalyzed Electrochemical Homo- and Heterocoupling Reaction of Terminal Alkynes: Synthesis, In Vitro Anticancer Activity, and Docking Study

With the objective to identify novel anticancer leads, herein ruthenium-catalyzed electrochemical homo- and heterocoupling reactions of terminal alkynes have been developed for the synthesis of the desired products. Among the synthesized 1,3-diynes, some of them were rigorously examined for possible in vitro anticancer activity against HeLa (human cervical cancer) and L6 normal (rat skeletal muscle) cell lines. Additionally, the docking study was also performed toward 16 ovarian cancer targets with binding affinity calculations with respect to the standard. To the best of our knowledge, this is the first scientific report on the ruthenium-catalyzed electrochemical homocoupling reaction between terminal alkynes with its in vitro anticancer and in silico docking studies.

Tuning of the redox potential and catalytic activity of a new Cu(ii) complex byo-iminobenzosemiquinone as an electron-reservoir ligand

The synthesis and characterization of a new Cu(ii) complex, LNIS2Cu^II(L^NIS=o-iminobenzosemiquinone), are reported.

(Ar-tpy)RuII(ACN)3: A Water-Soluble Catalyst for Aldehyde Amidation, Olefin Oxo-Scissoring, and Alkyne Oxygenation

The synthetic chemists always look for developing new catalysts, sustainable catalysis, and their applications in various organic transformations. Herein, we report a new class of water-soluble complexes, (Ar-tpy)Ru^II(ACN)₃, utilizing designed terpyridines possessing electron-donating and -withdrawing aromatic residues for tuning the catalytic activity of the Ru(II) complex. These complexes displayed excellent catalytic activity for several oxidative organic transformations including late-stage C-H functionalization of aldehydes with NH₂OR to valuable primary amides in nonconventional aqueous media with excellent yield. Its diverse catalytic power was established for direct oxo-scissoring of a wide range of alkenes to furnish aldehydes and/or ketones in high yield using a low catalyst loading in the water. Its smart catalytic activity under mild conditions was validated for dioxygenation of alkynes to highly demanding labile synthons, 1,2-diketones, and/or acids. This general and sustainable catalysis was successfully employed on sugar-based substrates to obtain the chiral amides, aldehydes, and labile 1,2-diketones. The catalyst is recovered and reused with a moderate turnover. The proposed mechanistic pathway is supported by isolation of the intermediates and their characterization. This multifaceted sustainable catalysis is a unique tool, especially for late-stage functionalization, to furnish the targeted compounds through frequently used amidation and oxygenation processes in the academia and industry.

Base-promoted amide synthesis from aliphatic amines and ynones as acylation agents through C-C bond cleavage

A new protocol for the synthesis of amides via base-promoted cleavage of the C(sp)-C(CO) bond of ynones with aliphatic primary and secondary amines under transition-metal-, ligand-, and oxidant-free conditions has been developed. This method exhibits a wide substrate scope, high functional group tolerance and exclusive chemoselectivity, as well as mild reaction conditions.

A double stranded metal-organic assembly accommodating a pair of water trimers in the host cavity and catalysing Glaser coupling

A supramolecular compound, catena-poly{[Cu2(1,3-μ2-(1a))2(μ2-ter)2(H2O)2]n·(6H2O)n} (1) has been synthesized using (1a) [(1a = N(1),N(3),N(5)-trimethyl-N(1),N(3),N(5)-tris((pyridin-4-yl)methyl)-1,3,5-benzene tricarboxamide] and terephthalate (ter) as the pillaring unit by self-assembly. The terephthalate units are connected by copper(II) ions forming a single strand, while a pair of such strands are then linked by (1a) via two pyridyl terminal arms bound to copper(II) nodes on either side forming a one-dimensional double stranded assembly propagating along the c axis. The compound crystallizes in the Fdd2 space group. The cavity created in the interior of this double strand assembly trap six water molecules and are stabilized by hydrogen bonding with the host. The arrangement of the pair of acyclic water trimers in isolated cavities of (1) is such that it resembles a closed-bracket-like formation. The Hirshfeld surface analysis of (1) reveals the presence of strong intermolecular hydrogen-bonding interactions between one-dimensional ladder-like units and with the water trimer in the host cavity. The copper(II)-containing coordination polymer also acts as an efficient catalyst for the Glaser-Hay homo-coupling reaction.

Efficient and environmentally friendly Glaser coupling of terminal alkynes catalyzed by multinuclear copper complexes under base-free conditions

An efficient catalytic system with multinuclear copper complexes as catalysts has been developed for the aerobic Glaser coupling reaction, which adopts environmentally friendly water as the solvent at room temperature under base-free condition.

An efficient CuI/DBU-catalyzed one-pot protocol for synthesis of 1,4-disubstituted 1,2,3-triazoles

A convenient CuI/DBU catalyzed one-pot method has been developed for the synthesis of 1,4-disubstituted 1,2,3-triazoles from aryl iodides, sodium azide and phenylacetaldehyde derivatives or from aryl iodides, sodium azide and alkynes in DMSO.