6312-25-0Relevant articles and documents
Exploring the acidic catalytic role of differently structured deep eutectic solvents in the aza-Michael addition of amines to 2-vinylpiridine
Ballarotto, Marco,Cappellini, Federico,Del Giacco, Tiziana,Di Profio, Pietro,Germani, Raimondo,Maestri, Riccardo,Tiecco, Matteo
, (2020/08/26)
Abstract: The search for innovative and green reaction media is a prominent topic in the recent research in chemistry. Deep Eutectic Solvents (DESs) are currently gaining relevance in this field thanks to their unique properties in terms of their “greenness” as well as in terms of their catalytic properties. In this work we developed an efficient protocol for the conjugate aza-Michael addition of amines to 2-vinylpyridine using 14 differently structured acid DESs as both reaction media and catalysts, so preventing the use of other acid additives. The results are influenced by the acidity of the components of the DESs, showing the best results with weak acids in the DESs components, with isolated yields up to 86%. The aza-Michael reaction is a widely used synthetic route for the C–N bond formation in organic synthesis. In particular, the addition of amines to 2-vinylpyridine is used for the realization of pharmaceutically relevant compounds with anticancer, antiarrhythmic, and analgesic properties. Comparing the results with the ones observed in literature for the same reaction, this procedure revealed to be a convenient and efficient method for this relevant transformation. Graphic abstract: [Figure not available: see fulltext.]
Synthesis and algicidal activity of new dichlorobenzylamine derivatives against harmful red tides
Choi, Dubok,Yu, Sunjong,Baek, Seung Ho,Kang, Yoon-Ho,Chang, Young-Cheol,Cho, Hoon
, p. 463 - 476 (2016/07/30)
In the present study, we synthesized 65 dichlorobenzylamine derivatives and investigated their algicidal activity against harmful red tides. The 3,4-dichlorobenzylamine derivatives showed relatively high activity against Cochlodinium polykrikoides, Heterosigma akashiwo, Chattonella marina, and Heterocapsa circularisquama, and the synthesized compounds 27, 28, 33, 34, 35, and 36 showed the highest algicidal activity after 24 h at 0.1 ~ 1.0 μM LC50 against the four harmful algae species. To verify the safety of the compounds, acute ecotoxicology tests using the water flea (Daphnia magna) and zebrafish (Danio rerio) were conducted, and the tests confirmed that compounds 33 and 34 were not harmful because the target organisms showed high survival rates at 15 μM. The results indicate that compounds 33 and 34 are suitable substances for use in controlling harmful algae species.
Fine-tuning of copper(I)-dioxygen reactivity by 2-(2-pyridyl)ethylamine bidentate ligands
Taki, Masayasu,Teramae, Shinichi,Nagatomo, Shigenori,Tachi, Yoshimitsu,Kitagawa, Teizo,Itoh, Shinobu,Fukuzumi, Shunichi
, p. 6367 - 6377 (2007/10/03)
Copper(I)-dioxygen reactivity has been examined using a series of 2-(2-pyridyl)ethylamine bidentate ligands R1Py1R2,R3. The bidentate ligand with the methyl substituent on the pyridine nucleus MePy1Et,Bz (N-benzyl-N-ethyl-2-(6-methylpyridin-2-yl)ethylamine) predominantly provided a (μ-η2:η2-peroxo)dicopper(II) complex, while the bidentate ligand without the 6-methyl group HPy1Et,Bz (N-benzyl-N-ethyl-2-(2-pyridyl)ethylamine) afforded a bis(μ-oxo)dicopper(III) complex under the same experimental conditions. Both Cu2O2 complexes gradually decompose, leading to oxidative N-dealkylation reaction of the benzyl group. Detailed kinetic analysis has revealed that the bis (μ-oxo)dicopper(III) complex is the common reactive intermediate in both cases and that O-O bond homolysis of the peroxo complex is the rate-determining step in the former case with MePy1Et,Bz. On the other hand, the copper(I) complex supported by the bidentate ligand with the smallest N-alkyl group (HPy1Me,Me, N,N-dimethyl-2-(2-pyridyl)ethylamine) reacts with molecular oxygen in a 3:1 ratio in acetone at a low temperature to give a mixed-valence trinuclear copper(II, II, III) complex with two μ3-oxo bridges, the UV-vis spectrum of which is very close to that of an active oxygen intermediate of lacase. Detailed spectroscopic analysis on the oxygenation reaction at different concentrations has indicated that a bis(μ-oxo)dicopper(III) complex is the precursor for the formation of trinuclear copper complex. In the reaction with 2,4-di-tert-butylphenol (DBP), the trinuclear copper(II, II, III) complex acts as a two-electron oxidant to produce an equimolar amount of the C-C coupling dimer of DBP (3,5,3′,5′tetra-tert-butyl-biphenyl-2,2′-diol) and a bis(μ-hydroxo)dicopper(II) complex. Kinetic analysis has shown that the reaction consists of two distinct steps, where the first step involves a binding of DBP to the trinuclear complex to give a certain intermediate that further reacts with the second molecule of DBP to give another intermediate, from which the final products are released. Steric and/or electronic effects of the 6-methyl group and the N-alkyl substituents of the bidentate ligands on the copper(I)-dioxygen reactivity have been discussed.
