110287-65-5Relevant academic research and scientific papers
Stereochemical substituent effects: Investigation of the cyano, amide and carboxylate group
Pedersen, Christian Marcus,Bols, Mikael
, p. 115 - 122 (2007/10/03)
Three pairs of diastereomeric piperidines, cis- and trans-2- methylpiperidine-3-carboxylate (6a and 6b), cis- and trans-2-methylpiperidine-3- carboxylamide (9a and 9b) and cis- and trans-2-methyl-3-cyanopiperidine (11a and 11b), were synthesised for the purpose of investigating the effect of the axial versus equatorial carboxylate, carboxamide and cyano group on piperidine base strength. The pKa values of the six compounds were determined to be 11.0 (6a), 10.4 (6b), 9.5 (9a), 9.3 (9b), 7.8 (11a) and 8.0 (11b). This shows that the strong electron-withdrawing effect of the cyano group and the effect of the amide group are relatively independent of spacial orientation. The carboxylate, on the other hand is considerably less electron-withdrawing when axial. Graphical Abstract.
Synthese et analyse conformationnelle de derives de l'acide nipecotique substitues par un reste methyle ou phenyle
Lapuyade, Gerard,Schlewer, Gilbert,Wermuth, Camille-Georges
, p. 663 - 668 (2007/10/02)
The synthesis and conformational analysis of methyl- or phenyl substituted nipecotic acid are reported.A chair conformation is always observed.If the configuration does permit it both the carboxylic group and the hydrocarbon substituent adopt the equatorial orientation.If a diequatorial orientation is impossible, an axial orientation is observed for the carboxylic group.
