Microwave effect for glycosylation promoted by solid super acid in supercritical carbon dioxide.
Int J Mol Sci
; 10(12): 5285-5295, 2009 Dec 08.
Article
in En
| MEDLINE
| ID: mdl-20054471
ABSTRACT
The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Acids
/
Carbon Dioxide
/
Microwaves
Language:
En
Journal:
Int J Mol Sci
Year:
2009
Document type:
Article
Affiliation country:
Japón