Enolate Enantioselective Protonation
2013
Marina Martjuga

Defending
03.01.2013. 14:00, Materiālzinātnes un lietišķās ķīmijas fakultātē, Āzenes ielā 14/24, 272. auditorijā.

Supervisor
Edgars Sūna

Reviewers
Māris Turks, Andris Zicmanis, Ronalds Zemribo

Dissertation is focused on synthesis of enantiomerically pure 1,3–diamines and their application in enantioselective protonation of lithium enolates. A methodology for stereoselective synthesis of chiral non-racemic 1,3-diamines has been developed based on a highly diastereoselective reduction of N-tert- butanesulfinylimines. A correlation between structure of N-tert-butanesulfinylimines (E/Z and M/P geometries) and sense of asymmetric induction in their reduction has been established. E/Z And M/P geometries of N-tert-butanesulfinylimines were determined both in crystalline form (by X-ray crystallographic analysis) and in THF– d8 solution (by NMR methods). Rate constants for E/Z isomerization and M/P atropisomerization as well as the corresponding Gibbs free energies of activation for isomerization were determined. Synthesized chiral non-racemic 1,3-diamines have been employed as chiral proton sources in enantioselective protonation of naproxen–derived lithium enolates. A relationship between steric hinderance of 1,3-diamines and enantioselectivity of proton transfer was studied. A principal chiral subunit in a 1,3-diamine, which ensures discrimination of enolate enantiotopic faces has been established.


Keywords
ENANTIOMERICALLY PURE 1,3-DIAMINES, DIASTEREOSELECTIVE REDUCTION, CHIRAL AUXILIARY, SULFINYL GROUP, SULFINYLIMINES, E/Z ISOMERS, M/P ATROPISOMERS, ACTIVATION BARRIER, GIBBS FREE ENERGY OF ACTIVATION, LITHIUM ENOLATES, ENANTIOSELECTIVE PROTONATION

Martjuga, Marina. Enolate Enantioselective Protonation. Promocijas darbs. Rīga: [RTU], 2013. pp.107.

Publication language
Latvian (lv)
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