Defining the Scope of the Acid-Catalyzed Glycosidation of Glycosyl Bromides

Graphical Abstract

“We would like to highlight two unique features of this approach. First, with reducing the amount of the silver salt, we were able to do a naked eye visual detection of the progress and completion of the reaction. Second, we have observed a very unusual reactivity trend for all glycosyl donors, according to which the classical disarmed sugars were deemed much more reactive than their armed counter parts.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 1042 ff. (DOI: 10.1002/chem.201904185).

Abstract

Invited for the cover of this issue are Yashapal Singh and Alexei Demchenko from the University of Missouri-St. Louis, USA. The image depicts the Koenigs and Knorr reaction, with the old car illustrating that the reaction is slow in the presence of silver(I) oxide, whereas the fast car shows that the reaction can be significantly accelerated by the addition of catalytic triflic acid. Read the full text of the article at 10.1002/chem.201904185.

Who designed the cover?

We have been collaborating with Fabia D'Amore-Krug, a talented artist who teaches art therapy. For our previous covers, all we had to do is describe the general outcome of our article in lay terms, and she would immediately come up with an image in her head. The fact that this reaction can now proceed much faster was shown by Fabia with two cars: old and slow versus new and fast. She quickly sketched the image of the two cars racing each other and came up with other ideas, such as gas stations, St. Louis skyline, etc. Fabia's initial sketch was done in pencil and then she created her final image in beautiful watercolor.

What was the biggest surprise?

We would like to highlight two unique features of this approach. First, with reducing the amount of the silver salt, we were able to do a naked eye visual detection of the progress and completion of the reaction. This is illustrated by a two-minute video of the reaction that has been supplied as a part of the Supporting Information. Second, we have observed a very unusual reactivity trend for all glycosyl donors, according to which the classical disarmed sugars were deemed much more reactive than their armed counter parts.

What other topics are you working on at the moment?

Our laboratory has been working in five major areas: 1) New synthetic reagents and building blocks. 2) Reactions for stereo-controlled glycosylation. 3) Expeditious strategies and automated technologies for oligosaccharide synthesis. 4) Biomedical studies on the development of glycopharmaceuticals. 5) Integration of glycans and nanomaterials in carbohydrate nanotechnology.