کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1344788 | 980137 | 2009 | 9 صفحه PDF | دانلود رایگان |
The resolution of N-chiral, amino acid-derived quaternary ammonium salts is demonstrated by using chiral BINOL as a complexing agent. Determination of the enantiopurities and absolute configurations of the resolved N-chiral tetraalkylammonium salts are described. The [1,2] Stevens rearrangement of N-chiral ammonium salts is shown to proceed with N-to-C chirality transmission to afford optically active 3-substituted morpholin-2-one derivatives.
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(R)-N-(tert-Butoxycarbonylmethyl)-N-(2-hydroxyethyl)-N-methyl-N-(2-methylbenzyl)ammonium bromideC17H28BrNO3Ee = 94%[α]58926=+13.3 (c 1.00, EtOH)Source of chirality: resolutionAbsolute configuration: (R)
(R)-N-(2-Hydroxyethyl)-N-(methoxycarbonylmethyl)-N-methyl-N-(2-methylbenzyl)ammonium bromideC14H22BrNO3Ee >95%[α]58924=+10.3 (c 1.00, EtOH)Source of chirality: resolutionAbsolute configuration: (R)
(S)-4-Methyl-3-(2-methylbenzyl)morpholin-2-oneC13H17NO2Ee = 60%[α]58922=+4.0 (c 1.00, EtOH)Source of chirality: asymmetric synthesisAbsolute configuration: (S)
Journal: Tetrahedron: Asymmetry - Volume 20, Issue 22, 26 November 2009, Pages 2600–2608