Amidophosphine Boranes as Hydroboration Reagents for Nitriles, Alkynes, and Carboxylic Acids.

We report here the hydroboration of nitriles, alkynes, and carboxylic acids using amidophosphine boranes {(BH 3 )(PPh 2 )-NC(CH 3 ) 3 }, {(BH 3 ) 2 (PPh) 2 N(CH 2 )C 6 H 5 }, and {(BH 3 ) 2 (PPh 2 ) 2 N-(BH 3 )CH 2 C 6 H 4 N} as reducing agents. These compounds were synthesized to replace more commonly used borane reagents. Solid amidophosphine boranes, which were synthesized with ease, demonstrated excellent reactivity and functional group tolerance toward a wide variety of nitriles, alkynes, and carboxylic acids, affording the corresponding ammonium salts, alkenes, and alcohols in good yield.