borane-ammonia complex
Ammonium formate powder (pulverized with mortar and pestle) 19 g (300 mmol) in a 0.5L round flask with a very large egg-shaped stir bar was dried on highvac overnight. Solid NaBH4 7.60g (200 mmol) was quickly added, followed by freshly distilled anhydrous dioxane 200 mL. The mixture was vigorously stirred under Ar with air-cooled condenser [ ]