Microfluidics-Based Ionic Catch and Release Oligosaccharide Synthesis (ICROS-Microflow) to Expedite Glycosylation Chemistry

A continuous microfluidic glycosylation strategy that requires no chromatography between steps and significantly expedites glycosylation chemistry is described. This practical approach incorporates the advantages of imidazolium-based chromatography-free purification and in situ mass spectrometry reaction monitoring to achieve fast reaction optimization and shorter reaction times. We demonstrate the utility of this strategy in the synthesis of a series of glycoside targets, including an α-(1,6)-trimannoside and a branched Man5 oligomannoside, within 1 day.

Comparison of glycosyl donors: a supramer approach

The development of new methods for chemical glycosylation commonly includes comparison of various glycosyl donors. An attempted comparison of chemical properties of two sialic acid-based thioglycoside glycosyl donors, differing only in the substituent at O-9 (trifluoroacetyl vs chloroacetyl), at different concentrations (0.05 and 0.15 mol·L-1) led to mutually excluding conclusions concerning their relative reactivity and selectivity, which prevented us from revealing a possible influence of remote protective groups at O-9 on glycosylation outcome. According to the results of the supramer analysis of the reaction solutions, this issue might be related to the formation of supramers of glycosyl donors differing in structure hence chemical properties. These results seem to imply that comparison of chemical properties of different glycosyl donors may not be as simple and straightforward as it is usually considered.

Computer Vision for Kinetic Analysis of Lab- and Process-Scale Mixing Phenomena

A software platform for the computer vision-enabled analysis of mixing phenomena of relevance to process scale-up is described. By bringing new and known time-resolved mixing metrics under one platform, hitherto unavailable comparisons of pixel-derived mixing metrics are exemplified across non-chemical and chemical processes. The analytical methods described are applicable using any camera and across an appreciable range of reactor scales, from development through to process scale-up. A case study in nucleophilic aromatic substitution run on a 5 L scale in a stirred tank reactor shows how camera and offline concentration analyses can be correlated. In some cases, it can be shown that camera data hold the power to predict reaction progress.