Staudinger reaction glycosyl azides

A variety of phosphate analogs have been synthesized and evaluated as glycosyl donors. Glycosyl phosphoramidimidates 73 are readily available from glycosyl phosphoramidites via a Staudinger reaction with phenyl azide (Scheme 6.14). Bearing... 

Malkinson, J. P., Falconer, R. A., and Toth, 1. (2000) Synthesis of C-terminal glycopeptides from resin-bound glycosyl azides via a modified Staudinger reaction. J. Org. Chem. 65, 5249-5252. 

Maunier, V, Boullanger, P, Lafont, D, A one-pot synthesis of glycosyl amides from glycosyl azides using a modified Staudinger reaction, J. Carbohydr. Chem., 16, 231-235, 1997. 

A second approach relies on the traceless Staudinger ligation between an appropriately functionalized phosphine and an azide to produce a new amide bond [54]. This method has found extensive utility in the labeling of peptides and proteins [215]. Importantly, this method has also been used for the construction of native iV-linked glycans through the reaction between a glycosyl azide and a phosphine containing amino acid [216,217]. 

The Staudinger reaction of protected glycosyl azides with triarylpho-... 

Tetra-O -acetyl-B-D-gluco- and -galacto-pyranosylamines (1) have been obtained from the corresponding glycosyl azides (2) by Staudinger reaction followed by hydrolysis of the intermediate phosphinimines (3) alternative reactions of intermediates (3) with carbon dioxide yielded the 1,2-trans-carbamates ( )... 

To form an anomeric N-acyl glycosylamine, the unsubstituted glyco-sylamine is usually used " but this form is quite labile and prone to potential anomerization and dimerization. Here the azide function was directly converted into its corresponding glycosyl amide without previous reduction to an amine. A modified Staudinger reaction was used with trimethylphosphine in the presence of different amino acids derivatives, for instance 26 activated with HOBt to give 27 (Scheme 5). 

Scheme 16.11 Mechanism of the Staudinger reaction with glycosyl azides...

Scheme 16.12 Three-component Staudinger-type reaction with ji-glycosyl azide 4 stereose-lectively leads to the ji-glycosyl amides 48. a-Clycosyl amides can only be obtained from a-glycosyl azide 49 with strong acylating agents to prevent complete anomerization of the Intermediate lmlnophosphorane °...

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