AMINOBOROHYDRIDES .3. A FACILE REDUCTION OF TERTIARY AMIDES TO THE CORRESPONDING AMINES AND ALCOHOLS IN HIGH-PURITY USING LITHIUM AMINOBOROHYDRIDES - STERICALLY CONTROLLED SELECTIVE C-N OR C-O BOND-CLEAVAGE

Lithium aminoborohydrides (LiABH3), obtained by the reaction of n-BuLi with amine-boranes, are powerful reducing agents or the reduction of tertiary amides to the corresponding amines or alcohols. Lithium pyrrolidinoborohydride (LiPyrrBH3) and lithium diisopropylaminoborohydride (LiH3BN(i-Pr)2) reduce both aliphatic and aromatic tertiary amides to give either the corresponding alcohol or amine, depending on the steric requirement of the tertiary amide and the LiABH3 used. The yields of amines and alcohols from this procedure range from very good to essentially quantitative.