Search for more stereoselective chiral lithium amides

SEARCH FOR MORE STEREOSELECTIVE CHIRAL LITHIUM AMIDES 

Amide 5 appears to be slightly less reactive than 4 in the deprotonation of 2 but as predicted the stereoselectivity was improved. The enantiomer composition of the deprotonation product was now 96.5% (5)-alcohol and 3.5% (R)-alcohol [19,22]. However, a kinetic investigation revealed that the composition of the activated complexes was different from that assumed in the theoretical model. The reaction orders showed that an activated complex is built from one molecule of chiral lithium amide dimer and one molecule of epoxide 2. Such activated complexes have been computationally modelled by the use of PM3 and optimized structures are displayed in Fig. 5 [19]. 

Entry Computational method X Solvent S Energy differences %(5) c./%(5) xp. 

Activated complexes involved in hthium amide deprotonation of 2 have been determined to contain one molecule of 2. 

Potential energy difference between the two most stable TSs at 298 K. 

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Search for more stereoselective chiral lithium amides... 

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