Reductive cleavage of axially disymmetric tertiary amines and quaternary ammonium salts by lithium aluminium hydride. Synthesis of new 1,1′-binaphthyl substituted amines

Axially disymmetric tertiary amines or quaternary ammonium salts $\text{A}$ are synthesized by double alkylation of primary or secondary amines with racemic or optically pure 2,2′-bis (bromomethyl)-1,1′-binaphthyl. Their reductive cleavage by lithium aluminium hydride in refluxing THF leads to chiral secondary or tertiary amines $\text{B}$, substituted by a binaphthyl unit, with high yields and absence of racemization.