title: 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.
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.
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authors.affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Goslinski
authors.affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Dutkiewicz
authors.affiliation: Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Kryjewski
authors.affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Tykarska
authors.affiliation: Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Sobotta
authors.affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Szczolko
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Gdaniec
authors.affiliation: Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Mielcarek
keywords: Alkylations; Density functional theory; Diaminomaleonitrile; Tribenzoporphyrazine; X-ray structure determination