Journal
SYMMETRY-BASEL
Volume 15, Issue 9, Pages -Publisher
MDPI
DOI: 10.3390/sym15091714
Keywords
idopyranoside; carbohydrates; chiral crown ethers; enantioselective synthesis; phase transfer catalysis
Categories
Ask authors/readers for more resources
Carbohydrate-based macrocycles can serve as enantioselective catalysts, and their catalytic activity can be influenced by the carbohydrate moiety. D-glucose and D-galactose-based crown ethers exhibit the best enantioselective properties. Incorporation of the rare monosaccharide D-idose into the macrocycle structure shows that enantioselectivity is dependent on the configuration of the anomeric center, the side arm of the nitrogen, and the substrate structure.
Carbohydrate-based macrocycles can be enantioselective catalysts in certain reactions. Previously, it was proven that the carbohydrate moiety could affect the catalytic activity of the monoaza-15-crown-5 type macrocycles derived from sugars. According to our experiments so far, the most effective enantioselective catalysts were the D-glucose- and the D-galactose-based crown ethers. To obtain more information about the effect of the carbohydrate unit, a rare monosaccharide, D-idose was incorporated into the monoaza-15-crown-5 structure. The key intermediates were methyl 4,6-O-benzylidene-ff-D-idopyranoside and methyl 4,6-O-benzylidene-beta-D-idopyranoside, which were synthesized from D-galactose. The efficiency of the idopyranoside-based crown compounds synthesized was investigated in asymmetric phase transfer reactions. In liquid-liquid biphasic reactions the highest enantioselectivity was 81% ee, while in solid-liquid phase systems the highest asymmetric induction was 67% ee. It was observed that the enantiodiscrimination was strongly dependent on the configuration of the anomeric center, on the side arm of the nitrogen, and on the structure of the substrate.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available