Efficient Hydroboration of Ketones and Imines Using Amidophosphine‐borane under Catalyst‐Free Conditions

We report here the use of amidophosphine borane {(BH₃)₂(PPh)₂N(CH₂)C₆H₅} as a competent reducing agent for the hydroboration of ketones and imines, yielding the corresponding secondary alcohols and secondary amines under mild and catalyst‐free reaction conditions. Solid amidophosphine boranes, which are easy to synthesize, and easy to handle demonstrated excellent reactivity and functional group tolerance toward a wide variety of ketones and imines, including aromatic, heteroaromatic, and aliphatic derivatives with electron‐withdrawing and electron‐donating substitutions, thus showing excellent chemoselectivity.