| Abstract: | Glycosyl isoquinoline‐1‐carboxylate was developed as a novel benchtop stable and readily available glycosyl donor. The glycosylation reaction was promoted by the inexpensive Cu(OTf)2 salt under mild reaction conditions. The copper isoquinoline‐1‐carboxylate salt was precipitated from the solution and thus rendered a traceless leaving group. Surprisingly, the proton from the acceptor was absorbed by the precipitated metal complex and the reaction mixture remained at neutral pH. The copper‐promoted glycosylation was also proven to be completely orthogonal to the gold‐promoted glycosylation, and an iterative synthesis of oligosaccharides from benchtop stable anomeric ester building blocks becomes possible under mild reaction conditions. |
