Carbon Dioxide-Mediated Preparation of Amine-Boranes

Since their discovery by Burg and Schlesinger in 1937, amine-boranes have enjoyed a rich preparative history and have experienced reinvigorated interest as valuable reagents for organic syntheses. Previously, the Herbert C. Brown Center for Borane Research has reported their synthesis from NaBH4 and amines via the intermediacy of (NH42SO4 or NaHCO3. Described herein is a CO2-mediated amine-borane synthesis that accommodates all classes of amines, particularly long-chain trialkyl- and pyridine-like heteroarylamines