Reversal diastereofacial selectivity in the n-butyllithium addition to O-protected N-trimethylsilylimines of (2S)-lactal: Enthalpic versus entropic contributions

Authors
Cainelli, G Giacomini, D Galletti, P
Citation
G. Cainelli et al., Reversal diastereofacial selectivity in the n-butyllithium addition to O-protected N-trimethylsilylimines of (2S)-lactal: Enthalpic versus entropic contributions, EUR J ORG C, (1), 1999, pp. 61-65
Citations number
44
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
ISSN journal
1434193X → ACNP
Issue
1
Year of publication
1999
Pages
61 - 65
Database
ISI
SICI code
1434-193X(199901):1<61:RDSITN>2.0.ZU;2-3
Abstract
Commonly observed, but rarely explored, is the possibility of modifying the diastereomeric excess (de%) by means of temperature. A complete reversal i n the diastereofacial selectivity could be obtained whenever the diastereoi somers concerned are differentially favored by enthalpy and entropy. The en thalpic or entropic dominance of a diastereoisomer depends greatly on the r eaction solvent used.