Aldol Reactions of Axially Chiral 5-Methyl-2-(o-aryl)imino-3-(o-aryl)-thiazolidine-4-ones
MOLECULES, cilt.21, sa.6, 2016 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 21 Sayı: 6
- Basım Tarihi: 2016
- Doi Numarası: 10.3390/molecules21060788
- Dergi Adı: MOLECULES
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Anahtar Kelimeler: chromatographic separations on a chiral stationary phase, axial chirality, aldol reactions of thiazolidine-4-ones, TERTIARY AMIDES, ATROPOSELECTIVITY, THIONAPHTHAMIDES, THIOBENZAMIDES, DERIVATIVES, PRODUCTS, BARRIERS
- İstanbul Üniversitesi-Cerrahpaşa Adresli: Hayır
Özet
Axially chiral 5-methyl-2-(o-aryl) imino-3-(o-aryl)-thiazolidine-4-ones have been subjected to aldol reactions with benzaldehyde to produce secondary carbinols which have been found to be separable by HPLC on a chiral stationary phase. Based on the reaction done on a single enantiomer resolved via a chromatographic separation from a racemic mixture of 5-methyl-2-(alpha-naphthyl) imino-3-(alpha-naphthyl)-thiazolidine-4-one by HPLC on a chiral stationary phase, the aldol reaction was shown to proceed via an enolate intermediate. The axially chiral enolate of the thiazolidine-4-one was found to shield one face of the heterocyclic ring rendering face selectivity with respect to the enolate. The selectivities observed at C-5 of the ring varied from none to 11.5:1 depending on the size of the ortho substituent. Although the aldol reaction proceeded with a lack of face selectivity with respect to benzaldehyde, recrystallization returned highly diastereomerically enriched products.