2,3-Di-O-picolinyl building blocks as glycosyl donors with switchable stereoselectivity

Org Biomol Chem. 2016 Mar 21;14(11):3159-69. doi: 10.1039/c6ob00107f. Epub 2016 Feb 25.

Abstract

2-O-Picolinyl protected glycosyl donors lead to the formation of 1,2-trans glycosides with complete stereoselectivity. This is due to the participatory effect of the picolinyl nitrogen that is able to block the bottom face of the ring via a six-membered cyclic intermediate. Herein we demonstrate that if the nitrogen atom of the O-picolinyl moiety is temporarily blocked by coordination to the metal center (Pd), it becomes unavailable to participate in glycosylation and hence the stereoselectivity of 2-O-picolinyl-assisted glycosylations can be "switched".

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Crystallography, X-Ray
  • Glycosides / chemical synthesis
  • Glycosides / chemistry*
  • Glycosylation
  • Models, Molecular
  • Picolines / chemistry*
  • Stereoisomerism

Substances

  • Glycosides
  • Picolines