Isolation of a 2-Hydroxytetrahydrofuran Complex from Copper-Promoted Hydroxylation of THF

A complex of a binucleating macrocyclic ligand comprising a [Cu-II(mu-OH)Na](2+) core reacts with CuI in THF/CH3CN to yield a novel species with a deprotonated 2-hydroxytetrahydrofuran (THF-2-ol) bridging between Cu-II and Na-I ions. The complexes were characterized by X-ray crystallography, electron paramagnetic resonance spectroscopy, and electrospray ionization mass spectrometry. O-18-labeling studies support incorporation of the O atom from mu-OH into the coordinated THF-2-ol ligand.