Structure and reactions of novel lithium dialkylamide aggregates and mixed aggregates
EMSL Project ID
2639
Abstract
Ab initio calculations will be performed to investigate novel lithium bases as reagents for the stereoselective synthesis of enolates. 3-Pentanone was selected as the ketone for this study because it can form only two diastereomeric enolates, and is the subject of experimental studies in my research group. The stereoselectivity of enolate formation is often dependent on the lithium amide base and the presence of other lithium salts, which tend to form mixed aggregates with lithium dialkylamides. Dilithiodiamines and molecules containing a lithium amide and another lithium containing functional group are expected to form intramolecular aggregates in solution that do not change during the course of the reactions. Ab initio calculations will be used to examine the formation of these intramolecular aggregates, and to examine the transition states leading to the selective formation of E or Z enolates. Geometry optimizations and transition state searches will be performed with the Gaussian and MS3 ab initio packages. The MS3 package is of interest because its parallel performance is reportedly better than that of Gaussian. The computational data on the E/Z enolization selectivity will be compared to the experimental results.
Project Details
Project type
Exploratory Research
Start Date
2002-10-01
End Date
2003-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Pratt LM, R Mu, C Carter, and B Woodford. 2007. "Mixed Aggregates of Dilithiodiamines with Alkyllithiums and Lithium Enolates." Tetrahedron 63(6):1331-1338.