A Mechanistic Probe into 1,2-cis Glycoside Formation Catalyzed by Phenanthroline and Further Expansion of Scope.

ABSTRACT: Phenanthroline, a rigid and planar compound with two fused pyridine rings, has been used as a powerful ligand for metals and a binding agent for DNA/RNA. We discovered that phenanthroline could be used as a nucleophilic catalyst to efficiently access high yielding and diastereoselective α-1,2-cis glycosides through the coupling of hydroxyl acceptors with α-glycosyl bromide donors. We have conducted an extensive investigation into the reaction mechanism, wherein the two glycosyl phenanthrolinium ion intermediates, a ⁴C₁ chair-liked β-conformer and a B_2,5 boat-like α-conformer, have been detected in a ratio of 2:1 (β:α) using variable temperature NMR experiments. Furthermore, NMR studies illustrate that a hydrogen bonding is formed between the second n

SUBMITTER: Li J 

PROVIDER: S-EPMC9009828 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature