112296-62-5Relevant academic research and scientific papers
Intramolecular diels-alder reaction in ionic liquids: Effect of ion-specific solvent friction
Tiwari, Shraeddha,Khupse, Nageshwar,Kumar, Anil
, p. 9075 - 9083 (2008)
(Chemical Equation Presented) The present work aims at understanding the role of viscosity or solvent friction in ionic liquids for an intramolecular Diels-Alder (IMDA) reaction of (E)-1-phenyl-4-[2-(3-methyl-2-butenyloxy) benzylidene]-5-pyrazolone (1). The results have been analyzed on the basis of the current theoretical models, and their failure to account for the observed trends is discussed in terms of "effective" viscosity or microviscosity. The rates of the reaction decrease with the increasing viscosity of the ionic liquids. As evident from the anionic effect, the solute-solvent specific interactions play a role in governing the kinetics of the reaction. The lower viscosities of the bistrifluoromethanesulfonimide [NTf2] - based ionic liquids as compared to those based on tetrafluoroborate [BF4]- anion fail to result in a corresponding acceleration in the rates of the reaction. These contradictory results indicate that solvent microviscosity, rather than the bulk macroscopic viscosity, should be the criteria for selecting the ionic liquids as reaction media.
Intramolecular Hetero-Diels-Alder Reaction of Alkylidene- and Benzylidenepyrazolones and Benzylideneisoxazolones. Investigations toward the Conformation of the Transition State
Tietze, Lutz F.,Brumby, Thomas,Pretor, Martina,Remberg, Gerd
, p. 810 - 820 (2007/10/02)
Stereochemical aspects of the intramolecular hetero-Diels-Alder reaction of hetero dienes are studied.Knoevenagel condensation of aromatic aldehydes 1, 12, 15,, and 21 with pyrazolones 8a-h and isoxazolone 17 gave the corresponding hetero dienes, e.g.,9a-
Stereospecificity in Intramolecular Hetero-Diels-Alder Reactions of 2-Benzylidene-1,3-dicarbonyl Compounds
Tietze, Lutz F.,Bratz, Matthias,Machinek, Reinchard,Kiedrowski, Guenter v.
, p. 1638 - 1640 (2007/10/02)
The intramolecular hetero-Diels-Alder reaction of 2-benzylidene-1,3-dicarbonyl compounds proceeds via a concerted pathway; this has been shown by using 13C-labeled dienophiles.
