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Novel cyano-activated Cu() complexes of arylhydrazones of active methylene nitriles and their catalytic application for azide-alkyne cycloaddition in water and glycerol
Ist Teil von
New journal of chemistry, 2023-05, Vol.47 (17), p.7965-7974
Ort / Verlag
Cambridge: Royal Society of Chemistry
Erscheinungsjahr
2023
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
The reaction of 2-(2-(dicyanomethylene)hydrazineyl)benzoic acid (H
2
L
1
) with copper(
ii
) acetate in the absence or presence of imidazole (im), 4,4′-bipyridine (4,4′-bipy) or pyridine (py) leads to the new complexes [Cu
2
(CH
3
OH)
2
(μ-L
1a
)
2
] (
1
), [Cu(L
1a
)(im)] (
2
), [Cu(L
1a
)(H
2
O)(4,4′-bipy)]·H
2
O (
3
) or [Cu(L
1a
)(py)]
n
(
4
), respectively, where (L
1a
)
2−
= (
Z
)-1-(2-carboxylatophenyl)-2-(1-cyano-2-imino-2-methoxyethylidene)hydrazin-1-ide. A one-pot activation of nitrile groups in the reaction of copper(
ii
) acetate monohydrate with 2-(2-(dicyanomethylene)hydrazineyl)terephthalic acid (H
3
L
2
) in the presence of pyridine in methanol affords the trinuclear Cu(
ii
) complex [Cu(py)
2
{Cu(py)(μ-L
2a
)}
2
] (
5
), where (L
2a
)
3−
= (
Z
)-2-((1-cyano-2-imino-2-methoxyethylidene)-1-(2,5-dicarboxylatophenyl)hydrazin-1-ide). Both arylhydrazone ligands and the auxiliary ligands were used to modulate the nuclearity and design of the supramolecular arrangements of the obtained Cu(
ii
) complexes. The complexes were characterized by elemental analyses, electrospray ionization mass spectrometry (ESI-MS), and FT-IR spectroscopy. Their molecular structures were established using single crystal X-ray diffraction (SCXRD) analysis. The catalytic activity of the complexes was investigated for the microwave assisted 1,3-dipolar azide-alkyne cycloaddition reaction using a mixture of water and glycerol as reaction medium. Pre-catalyst
1
was found to be the most efficient one by affording a quantitative conversion to 1,4-disubstituted-1,2,3-triazoles after 30 minutes at 125 °C. The catalytic system proceeds with a broad scope of substrates according to "Click" rules.
Synthesis of five novel copper-arylhydrazone complexes and their catalytic activity for microwave-assisted click reaction in water and glycerol.