Steric and Electronic Effects on ^(15)N Chemical Shifts of Piperidine and Decahydroquinoline Hydrochlorides
- Creators
- Duthaler, Rudolf O.
- Roberts, John D.
Abstract
Natural-abundance ^(15)N NMR chemical shifts of a number of closely related C- and N-methyl-substituted piperidine and decahydroquinoline hydrochlorides have been measured in chloroform and methanol. For each solvent, the ^(15)N shifts of the salts of secondary and tertiary amines give different linear correlations with the ^(13)C shifts of the corresponding carbons of their hydrocarbon analogues. Additive shift parameters as well as protonation-shift parameters for carbon substitution near nitrogen have been determined. Three of the nine parameters have a pronounced solvent dependence. The substituent-shift parameters for hydrochlorides are in general closer to the analogous values for ^(13)C NMR than the corresponding parameters which correlate the I5N shifts of the free amines. The parameters for substitution on @carbons are an exception. The ^(13)C shifts of some of the compounds can be used to elucidate conformational questions.
Additional Information
© 1978 American Chemical Society. Received August 12, 1977. We wish to thank Professor M. Allen for providing a very useful computer program doing least-squares multilinear regression analysis, and Professor K. L. Williamson for preparing and measuring the shifts of 8-(e)-methyltrans-decahydroquinoline. We are also indebted to Dr. André Gagneux of Ciba-Geigy AG, Basel, who provided a sample of 2-azaadamantane, to Professor Robert T. LaLonde of the College of Environmental Science and Forestry, State University of New York at Syracuse, for the sample of 3-methylquinolizidine, and to Dr. D. K. Dalling of the University of Utah for calculations of ^(13)C chemical shifts of decalins. Supported by the National Science Foundation, and by the Public Health Service, Research Grant GM-11072 from the Division of General Medical Sciences.Additional details
- Alternative title
- Steric and electronic effects on nitrogen-15 chemical shifts of piperidine and decahydroquinoline hydrochlorides
- Eprint ID
- 60885
- DOI
- 10.1021/ja00480a037
- Resolver ID
- CaltechAUTHORS:20151008-070942817
- NSF
- U.S. Public Health Service (USPHS)
- GM-11072
- Created
-
2015-10-08Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Gates and Crellin Laboratories of Chemistry
- Other Numbering System Identifier
- 5647