Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings

Thiouracil catalyzes stereoselective glycosylations with galactals in loadings as low as 0.1 mol%. It is proposed that in these glycosylations thiouracil, monothiophthalimide, and the previously reported catalyst, Schreiner's thiourea, do not operate via a double H-bonding mechanism but rather...

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Autores principales: Bradshaw, G. A., Colgan, A. C., Allen, N. P., Pongener, I., Boland, M. B., Ortin, Y., McGarrigle, E. M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2018
Materias:
Chemistry
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334493/
https://www.ncbi.nlm.nih.gov/pubmed/30713648
http://dx.doi.org/10.1039/c8sc02788a
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author Bradshaw, G. A.
Colgan, A. C.
Allen, N. P.
Pongener, I.
Boland, M. B.
Ortin, Y.
McGarrigle, E. M.
author_facet Bradshaw, G. A.
Colgan, A. C.
Allen, N. P.
Pongener, I.
Boland, M. B.
Ortin, Y.
McGarrigle, E. M.
author_sort Bradshaw, G. A.
collection PubMed
description Thiouracil catalyzes stereoselective glycosylations with galactals in loadings as low as 0.1 mol%. It is proposed that in these glycosylations thiouracil, monothiophthalimide, and the previously reported catalyst, Schreiner's thiourea, do not operate via a double H-bonding mechanism but rather by Brønsted acid/base catalysis. In addition to the synthesis of 2-deoxyglycosides and glycoconjugates, we report the first organocatalytic synthesis of 1,1′-linked trehalose-type sugars.
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spelling pubmed-63344932019-02-01 Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings Bradshaw, G. A. Colgan, A. C. Allen, N. P. Pongener, I. Boland, M. B. Ortin, Y. McGarrigle, E. M. Chem Sci Chemistry Thiouracil catalyzes stereoselective glycosylations with galactals in loadings as low as 0.1 mol%. It is proposed that in these glycosylations thiouracil, monothiophthalimide, and the previously reported catalyst, Schreiner's thiourea, do not operate via a double H-bonding mechanism but rather by Brønsted acid/base catalysis. In addition to the synthesis of 2-deoxyglycosides and glycoconjugates, we report the first organocatalytic synthesis of 1,1′-linked trehalose-type sugars. Royal Society of Chemistry 2018-10-22 /pmc/articles/PMC6334493/ /pubmed/30713648 http://dx.doi.org/10.1039/c8sc02788a Text en This journal is © The Royal Society of Chemistry 2019 http://creativecommons.org/licenses/by/3.0/ This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0)
spellingShingle Chemistry
Bradshaw, G. A.
Colgan, A. C.
Allen, N. P.
Pongener, I.
Boland, M. B.
Ortin, Y.
McGarrigle, E. M.
Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings
title Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings
title_full Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings
title_fullStr Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings
title_full_unstemmed Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings
title_short Stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as Brønsted acid catalysts at low loadings
title_sort stereoselective organocatalyzed glycosylations – thiouracil, thioureas and monothiophthalimide act as brønsted acid catalysts at low loadings
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334493/
https://www.ncbi.nlm.nih.gov/pubmed/30713648
http://dx.doi.org/10.1039/c8sc02788a
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