Site-Selective Acylation of Pyranosides with Oligopeptide Catalysts

• Published in: Journal of organic chemistry Vol. 86; no. 5; pp. 3907 - 3922
• Main Authors: Seitz, Alexander, Wende, Raffael C, Roesner, Emily, Niedek, Dominik, Topp, Christopher, Colgan, Avene C, McGarrigle, Eoghan M, Schreiner, Peter R
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 05-03-2021
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/acs.joc.0c02772

Herein, we report the oligopeptide-catalyzed site-selective acylation of partially protected monosaccharides. We identified catalysts that invert site-selectivity compared to N-methylimidazole, which was used to determine the intrinsic reactivity, for 4,6-O-protected glucopyranosides (trans-diols) as well as 4,6-O-protected mannopyranosides (cis-diols). The reaction yields up to 81% of the inherently unfavored 2-O-acetylated products with selectivities up to 15:1 using mild reaction conditions. We also determined the influence of protecting groups on the reaction and demonstrate that our protocol is suitable for one-pot reactions with multiple consecutive protection steps.