Glycosylation reactions proton transfer

The Role of Proton Transfer in the Transition State for Glycosylation Reactions [ 30... 

The transition states for glycosylation reactions involve proton transfer in most cases. The acidity of the alcoholic nucleophile increases as the degree of ionization of the glycosyl donor increases (see Scheme 18). 

Experimental and/or theoretical studies to assess the role of H-bonding and proton transfer at or near the TS of glycosylation reactions. This not only requires reliable models of TSs, but also good computational methods for H-bonding. 

To develop novel protecting groups or some other strategy to promote proton transfer in the TS of glycosylation reactions. These should be particularly aimed at activating unreactive hydroxyl groups. 

Assess the role of trace amounts of water or other possible proton-relay molecules in glycosylation reactions. In the acyl-transfer model a relay molecule was found to lower the barrier for proton transfer. 

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