Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation
A mild and convenient method for the synthesis of α-glycosyl chlorides in high 80–96 % yields within 15–30 min using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) is disclosed. The method has a wide substrate scope and is compatible with labile OH protecting groups, including benzyl, acetyl, ben...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2020
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/139778 |
| _version_ | 1826111085930872832 |
|---|---|
| author | Tatina, Madhu Babu Khong, Duc Thinh Judeh, Zaher M.A. |
| author2 | School of Chemical and Biomedical Engineering |
| author_facet | School of Chemical and Biomedical Engineering Tatina, Madhu Babu Khong, Duc Thinh Judeh, Zaher M.A. |
| author_sort | Tatina, Madhu Babu |
| collection | NTU |
| description | A mild and convenient method for the synthesis of α-glycosyl chlorides in high 80–96 % yields within 15–30 min using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) is disclosed. The method has a wide substrate scope and is compatible with labile OH protecting groups, including benzyl, acetyl, benzoyl, isopropylidene, benzylidene, TBDMS (tert-butyldimethylsilyl), and TBDPS (tert-butyldiphenylsilyl) groups. The excellent α selectivity obtained in this reaction is attributed to in-situ isomerization of β-glycosyl chlorides to the more stable α-glycosyl chlorides, as demonstrated by 1H NMR spectroscopic studies. Disarmed sugars with OBz or OAc groups at C-2 were chlorinated at a faster rate but ismomerized (β→α) at a slower rate than armed sugars with an OBn group at C-2. More importantly, the method enables highly desirable one-pot glycosylation reactions to take place, thus allowing efficient syntheses of disaccharides and simple O-glycosylated sugars in high overall yields without the need for separation or purification of the α-glycosyl chloride donors. This method will be especially useful for direct glycosylation reactions using glycosyl chloride donors that are unstable upon separation and purification. |
| first_indexed | 2024-10-01T02:44:52Z |
| format | Journal Article |
| id | ntu-10356/139778 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:44:52Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1397782020-05-21T07:47:24Z Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation Tatina, Madhu Babu Khong, Duc Thinh Judeh, Zaher M.A. School of Chemical and Biomedical Engineering Engineering::Chemical engineering::Biochemical engineering Carbohydrates Chlorine A mild and convenient method for the synthesis of α-glycosyl chlorides in high 80–96 % yields within 15–30 min using 2-chloro-1,3-dimethylimidazolinium chloride (DMC) is disclosed. The method has a wide substrate scope and is compatible with labile OH protecting groups, including benzyl, acetyl, benzoyl, isopropylidene, benzylidene, TBDMS (tert-butyldimethylsilyl), and TBDPS (tert-butyldiphenylsilyl) groups. The excellent α selectivity obtained in this reaction is attributed to in-situ isomerization of β-glycosyl chlorides to the more stable α-glycosyl chlorides, as demonstrated by 1H NMR spectroscopic studies. Disarmed sugars with OBz or OAc groups at C-2 were chlorinated at a faster rate but ismomerized (β→α) at a slower rate than armed sugars with an OBn group at C-2. More importantly, the method enables highly desirable one-pot glycosylation reactions to take place, thus allowing efficient syntheses of disaccharides and simple O-glycosylated sugars in high overall yields without the need for separation or purification of the α-glycosyl chloride donors. This method will be especially useful for direct glycosylation reactions using glycosyl chloride donors that are unstable upon separation and purification. 2020-05-21T07:47:24Z 2020-05-21T07:47:24Z 2018 Journal Article Tatina, M. B., Khong, D. T., & Judeh, Z. M. A. (2018). Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation. European Journal of Organic Chemistry, 2018(19), 2208-2213. doi:10.1002/ejoc.201800360 1434-193X https://hdl.handle.net/10356/139778 10.1002/ejoc.201800360 2-s2.0-85047660957 19 2018 2208 2213 en European Journal of Organic Chemistry © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. |
| spellingShingle | Engineering::Chemical engineering::Biochemical engineering Carbohydrates Chlorine Tatina, Madhu Babu Khong, Duc Thinh Judeh, Zaher M.A. Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation |
| title | Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation |
| title_full | Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation |
| title_fullStr | Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation |
| title_full_unstemmed | Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation |
| title_short | Efficient synthesis of α-glycosyl chlorides using 2-chloro-1,3-dimethylimidazolinium chloride : a convenient protocol for quick one-pot glycosylation |
| title_sort | efficient synthesis of α glycosyl chlorides using 2 chloro 1 3 dimethylimidazolinium chloride a convenient protocol for quick one pot glycosylation |
| topic | Engineering::Chemical engineering::Biochemical engineering Carbohydrates Chlorine |
| url | https://hdl.handle.net/10356/139778 |
| work_keys_str_mv | AT tatinamadhubabu efficientsynthesisofaglycosylchloridesusing2chloro13dimethylimidazoliniumchlorideaconvenientprotocolforquickonepotglycosylation AT khongducthinh efficientsynthesisofaglycosylchloridesusing2chloro13dimethylimidazoliniumchlorideaconvenientprotocolforquickonepotglycosylation AT judehzaherma efficientsynthesisofaglycosylchloridesusing2chloro13dimethylimidazoliniumchlorideaconvenientprotocolforquickonepotglycosylation |