ISSN:
1434-193X
Schlagwort(e):
Asymmetric synthesis
;
Grignard reactions
;
Dynamic kinetic resolution
;
Asymmetric synthesis
;
Unsymmetrical 1,2-diamines
;
Chemistry
;
General Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
---A diastereoselective synthesis of tert-butyl-1,2-diamines has been developed from the addition of tert-butylmagnesium chloride to the 1,2-bisimines derived from glyoxal and chiral amines such as 1-(S)-ethylphenylamine, 1-(S)-phenylpropylamine or 1-(S)-(p-chlorophenyl)ethylamine. The influence of solvent, temperature and chiral auxiliaries on the chemical reactivity and stereoselectivity has been fully studied. Evidence of a dynamic kinetic resolution during the bis-addition process of the organometallic, leading to the 1,2-di-tert-butylethanediamine,[1] as a single diastereomer, has been demonstrated. This resolution has been applied with high diastereoselectivities to the synthesis of unsymmetrical disubstituted 1,2-diamines, by addition of one equivalent of tert-butylmagnesium chloride, followed by one equivalent of a second Grignard reagent. Several chiral 1-tert-butyl-1,2-diamines have also been synthesized by monoaddition of tert-butylmagnesium chloride to the bisimines, followed by hydride reduction of the chiral intermediate imines.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
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