Study of interhalogens/silver trifluoromethanesulfonate as promoter systems for high-yielding sialylations
(2002) In Journal of Organic Chemistry 67(21). p.7407-7412- Abstract
- We have studied interhalogen/silver trifluoromethanesulfonate (IX/AgOTf) promoted glycosylations and found differences in the sensitivity of the formed oxocarbenium ions (e.g. from compounds with or without participating groups) toward halide nucleophiles. These differences can be explained using the HSAB theory. By applying this theory on sialylations, we increased the yield for a model reaction from a highly unpredictable 35-46% using ICl to 74% using IBr. We have also showed that the most prominent role of the silver ions is lowering the concentration of the halide nucleophile rather than activating the interhalogen compound and, by increasing the amount of AgOTf from 1 to 1.5 equiv (with respect to IBr), the yield in the model reaction... (More)
- We have studied interhalogen/silver trifluoromethanesulfonate (IX/AgOTf) promoted glycosylations and found differences in the sensitivity of the formed oxocarbenium ions (e.g. from compounds with or without participating groups) toward halide nucleophiles. These differences can be explained using the HSAB theory. By applying this theory on sialylations, we increased the yield for a model reaction from a highly unpredictable 35-46% using ICl to 74% using IBr. We have also showed that the most prominent role of the silver ions is lowering the concentration of the halide nucleophile rather than activating the interhalogen compound and, by increasing the amount of AgOTf from 1 to 1.5 equiv (with respect to IBr), the yield in the model reaction improved from 74% to 89%. A comparison of two different anomeric leaving groups showed that glycal formation can be minimized using a thiophenyl donor instead of xanthate. By combining these observations, we were able to increase the yield of the model reaction to 97%. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/325581
- author
- Meijer, Andréas LU and Ellervik, Ulf LU
- organization
- publishing date
- 2002
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Organic Chemistry
- volume
- 67
- issue
- 21
- pages
- 7407 - 7412
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:12375971
- wos:000178598600030
- scopus:0037131383
- ISSN
- 1520-6904
- DOI
- 10.1021/jo0262412
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Organic chemistry (S/LTH) (011001240)
- id
- 8769e900-53a3-4bf3-9e4b-954f8a084d38 (old id 325581)
- date added to LUP
- 2016-04-01 12:04:26
- date last changed
- 2024-02-23 17:50:30
@article{8769e900-53a3-4bf3-9e4b-954f8a084d38, abstract = {{We have studied interhalogen/silver trifluoromethanesulfonate (IX/AgOTf) promoted glycosylations and found differences in the sensitivity of the formed oxocarbenium ions (e.g. from compounds with or without participating groups) toward halide nucleophiles. These differences can be explained using the HSAB theory. By applying this theory on sialylations, we increased the yield for a model reaction from a highly unpredictable 35-46% using ICl to 74% using IBr. We have also showed that the most prominent role of the silver ions is lowering the concentration of the halide nucleophile rather than activating the interhalogen compound and, by increasing the amount of AgOTf from 1 to 1.5 equiv (with respect to IBr), the yield in the model reaction improved from 74% to 89%. A comparison of two different anomeric leaving groups showed that glycal formation can be minimized using a thiophenyl donor instead of xanthate. By combining these observations, we were able to increase the yield of the model reaction to 97%.}}, author = {{Meijer, Andréas and Ellervik, Ulf}}, issn = {{1520-6904}}, language = {{eng}}, number = {{21}}, pages = {{7407--7412}}, publisher = {{The American Chemical Society (ACS)}}, series = {{Journal of Organic Chemistry}}, title = {{Study of interhalogens/silver trifluoromethanesulfonate as promoter systems for high-yielding sialylations}}, url = {{http://dx.doi.org/10.1021/jo0262412}}, doi = {{10.1021/jo0262412}}, volume = {{67}}, year = {{2002}}, }