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Experimental and computational study on the reactivity of 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile, a key intermediate for the synthesis of tribenzoporphyrazine bearing peripheral methyl(3-pyridylmethyl)amino substituents.

Goslinski T, Dutkiewicz Z, Kryjewski M, Tykarska E, Sobotta L, Szczolko W, Gdaniec M, Mielcarek J - Monatsh. Chem. (2011)

Bottom Line: The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction.The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion.This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring. .

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.

ABSTRACT

Abstract: An earlier developed alkylating path leading to tetraalkylated diaminomaleonitrile derivatives was explored. Attempts to explain the reactivity of the representative dialkylated diaminomaleonitrile 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile during the alkylation reaction were performed using X-ray and density functional theory (DFT) studies. The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction. The values of the Fukui functions and condensed softness for electrophilic attack calculated from Mulliken, Löwdin, and natural population analyses closely corresponded to the experimental observations. When 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile disodium salt was treated with dimethyl sulfate at lower temperatures the alkylation reaction prevailed, whereas at higher temperatures the alkylating agent acted as a hydride anion acceptor, which favored the elimination reaction. The tetraalkylated dinitrile 2,3-bis[methyl(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile was used in the synthesis of tribenzoporphyrazine bearing methyl(3-pyridylmethyl)amino groups, which was subsequently subjected to solvatochromic and metallation studies. The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion. This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring.

Graphical abstract: .

No MeSH data available.


Tribenzoporphyrazine 8 (black line) titrated with PdCl2(PhCN)2 in dichloromethane:methanol (1:1). Variations of the Q-band in different solvents (inset)
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Fig4: Tribenzoporphyrazine 8 (black line) titrated with PdCl2(PhCN)2 in dichloromethane:methanol (1:1). Variations of the Q-band in different solvents (inset)

Mentions: UV–Vis spectroscopy was employed to evaluate solvatochromic effects of 8 and 9. In dichloromethane:methanol (1:1) solution, tribenzoporphyrazine 8 exhibits a Soret peak at 332 nm and Q-band at 730 nm with shoulders at 660 and 810 nm. Solvatochromic studies performed on 8 (Fig. 4) and 9 (Fig. 11S, Supplementary Material) in various aprotic and protic solvents revealed the Q-band changes in the range from 723 nm (acetonitrile) to 736 nm (pyridine) [22, 23]. The Q-band wavelength is better correlated to the refractive index than the dipole moment for 8 and 9 (Table 2), suggesting that the red-shift is due to solvation rather than coordination.Fig. 4


Experimental and computational study on the reactivity of 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile, a key intermediate for the synthesis of tribenzoporphyrazine bearing peripheral methyl(3-pyridylmethyl)amino substituents.

Goslinski T, Dutkiewicz Z, Kryjewski M, Tykarska E, Sobotta L, Szczolko W, Gdaniec M, Mielcarek J - Monatsh. Chem. (2011)

Tribenzoporphyrazine 8 (black line) titrated with PdCl2(PhCN)2 in dichloromethane:methanol (1:1). Variations of the Q-band in different solvents (inset)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4495027&req=5

Fig4: Tribenzoporphyrazine 8 (black line) titrated with PdCl2(PhCN)2 in dichloromethane:methanol (1:1). Variations of the Q-band in different solvents (inset)
Mentions: UV–Vis spectroscopy was employed to evaluate solvatochromic effects of 8 and 9. In dichloromethane:methanol (1:1) solution, tribenzoporphyrazine 8 exhibits a Soret peak at 332 nm and Q-band at 730 nm with shoulders at 660 and 810 nm. Solvatochromic studies performed on 8 (Fig. 4) and 9 (Fig. 11S, Supplementary Material) in various aprotic and protic solvents revealed the Q-band changes in the range from 723 nm (acetonitrile) to 736 nm (pyridine) [22, 23]. The Q-band wavelength is better correlated to the refractive index than the dipole moment for 8 and 9 (Table 2), suggesting that the red-shift is due to solvation rather than coordination.Fig. 4

Bottom Line: The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction.The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion.This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring. .

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.

ABSTRACT

Abstract: An earlier developed alkylating path leading to tetraalkylated diaminomaleonitrile derivatives was explored. Attempts to explain the reactivity of the representative dialkylated diaminomaleonitrile 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile during the alkylation reaction were performed using X-ray and density functional theory (DFT) studies. The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction. The values of the Fukui functions and condensed softness for electrophilic attack calculated from Mulliken, Löwdin, and natural population analyses closely corresponded to the experimental observations. When 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile disodium salt was treated with dimethyl sulfate at lower temperatures the alkylation reaction prevailed, whereas at higher temperatures the alkylating agent acted as a hydride anion acceptor, which favored the elimination reaction. The tetraalkylated dinitrile 2,3-bis[methyl(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile was used in the synthesis of tribenzoporphyrazine bearing methyl(3-pyridylmethyl)amino groups, which was subsequently subjected to solvatochromic and metallation studies. The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion. This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring.

Graphical abstract: .

No MeSH data available.