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Reactions of Chiral Imines with Heteroatom-substituted Dienes

Reactions of Chiral Imines with Heteroatom-substituted Dienes [Pg.81]

Reactions of imines derived from valine tert-butyl ester with Brassard s diene proceed highly stereoselective in the presence of Lewis acids, such as EtAlCl2, at low temperature. Removal of the chiral auxiliary is achieved via a Curtius rearrangement. [Pg.81]

Lewis acid-catalyzed (EtAlCla, ZnClz) aza Diels-Alder reaction of imines derived from amino acid esters or carbohydrates with Danishefsky s diene provide precursors of chiral piperidine alkaloids. When using imines derived from 0-pivaloylated glycosylamines and ZnCl2 as Lewis acid, highly diastereoselective tandem-Mannich-Michael reactions are observed. The carbohydrate moiety is easily removed by treatment with HCl/MeOH. By employing galactopyranosylamine or arabinosylamine derivatives both enantiomeric series are readily available. [Pg.81]

3 Reactions of Achiral Imines with Chiral Heteroatom-substituted Dienes [Pg.83]

Chiral 2-amino-l,3-butadienes derived from 2-(methoxymethyl)pyrrolidine and a-oxo enamines undergo cycloadditions with jV-silylimines in the presence of ZnCl2 to yield 4-piperidinones stereoselectively upon subsequent hydrolysis with aqueous NaHCOs. [Pg.83]




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Chiral dienes

Chiral imine

Diene reaction

Dienes heteroatom-substituted

Dienes imines

Dienes substituted

Dienes, reactions

Heteroatom substituted diene

Heteroatom substitution

Heteroatom-substituted

Imine reaction

Imines chiral

Imines substituted

Imines with dienes

Imines, reactions

Of imines

Reaction with imines

Reactions chiral

Reactions of Chiral Imines with Dienes

Reactions of Dienes

Reactions of Imines

Reactions with dienes

Substituted reaction with

Substitution heteroatom-substituted

With imines

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