Efficient Catalytic Deoxygenation of Epoxides Using [Tris(3,5-dimethylpyrazolyl)hydridoborato]rhenium Oxides

Abstract

In situ reduction of Tp‘ReO3 (Tp‘ = tris(3,5-dimethylpyrazolyl)hydridoborate) using triphenylphosphine or triethyl phosphite allows generation of a reduced rhenium species that catalyzes efficient O atom transfer from epoxides to the stoichiometric phosphorus reductant at 75−105 °C. The reaction is stereospecific and proceeds most rapidly with cis- vs trans-alkenes. The choice of ligand is shown to impart advantages to design of the catalytic cycle.