Glycosylation of alcohols using glycosyl boranophosphates as glycosyl donors

A novel glycosylation that uses glycosyl boranophosphate triesters as glycosyl donors and trityl cation (Tr+) as an activator was developed. Two types of reactions were studied: (1) the boranophosphate triester was activated with TrNTf2 to react with an alcohol and (2) O-trityl ethers worked as both glycosyl acceptors and Tr+ sources. The latter gave better results and the desired O-glycosylation products were rapidly generated and isolated in moderate to good yields.