4999-94-4Relevant academic research and scientific papers
1,2,3-triazole[4,5-d]pyridazines-II. New derivatives tested on adenosine receptors
Biagi,Giorgi,Livi,Scartoni,Martini,Tacchi,Merlino,Pasero
, p. 175 - 181 (2007/10/02)
This paper reports the synthesis and biological evaluation towards A1 and A2 adenosine receptors of new 1,2,3-triazole[4,5-d]pyridazines bearing lipophilic substituents in the 1 position. Some 1-benzyl-4-substituted amino derivatives
SITE-SELECTIVITY OF 1,3-DIPOLAR CYCLOADDITIONS TO 2,3-DIMETHOXYCARBONYL-7-OXABICYCLO-HEPTADIENE
Fisera, Lubor,Povazanec, Frantisek,Zalupsky, Peter,Kovac, Jaroslav,Pavlovic, Dusan
, p. 3144 - 3153 (2007/10/02)
Site-selectivity of dipolar cycloaddition to the title compound was studied.Azomethine X afforded a 1:1 cycloadduct XI at the deactivated double bond at room temperature;upon thermolysis at 110 degC it afforded the acetylated enamine XIII, wich was formed wia a direct cycloaddition at the mentioned temperature.The cycloaddition course was investigated in various solvents;the enamine XIV formed by solvolysis of XIII was the final products in methanol.Cycloaddition of title compound to azides, benzoylnitrile N-oxide and C-acetyl-N-phenylnitrilimine furnished the product of cycloreversion instead of the not isolable 1:1 cycloadducts.5-Azido-2-furancarbaldehyde and 4-nitrophenylazide yielded cycloaddition products to both multiple bonds in an approximately 1:1 ratio: HN3, tosylazide,benzoylnitrile N-oxide and C-acetyl-N-phenylnitrilimine gave the addition products to the deactivated double bond.The solvent-effect of site-selectivity of 1,3-dipolarcycloaddition was inwestigated and the title compound was found to be an exellent synthetic equivalent for acetylene and dimethyl butinedioate.
SITE SELECTIVITY IN THE REACTIONS OF 1,3-DIPOLES WITH NORBORNADIENE DERIVATIVES
Cristina, D.,Amici, M. De,Micheli, C. De,Gandolfi, R.
, p. 1349 - 1357 (2007/10/02)
The cycloadditions of arylazides, benzonitrile oxides and diphenylnitrile imine to norbornadiene derivatives 1a-c showed varying degree of site- and stereo-selectivity.With dipolarophile 1a arylazides and benzonitrile oxides attack, preferentially, the electron-poor tetrasubstituted double bond, while in the case of 1b and 1c is the substituted double bond which enters the cycloaddition.By contrast, 2-diazopropane and C-phenyl-N-methylnitrone react with the sole tetrasubstituted double bond of 1a-c in stereo- and site-specific cycloadditions.The quantitative evaluation of the two possible reaction paths was performed by glc analysis.The compounds detected were those arising from Diels-Alder cycloreversions of the thermally labile intermediate adducts 2 and 3 (Scheme 1).The results were rationalized on the basis of a qualitative perturbation treatment which considers frontier orbital interactions only.
