Aminoborohydrides. 14. Lithium Aminoborohydrides in the Selective Reduction or Amination of Alkyl Methanesulfonate Esters

Lithium aminoborohydride (LAB) reagents initiate the amination or reduction of alkyl methanesulfonate esters, as dictated by reaction conditions. Alkyl methanesulfonate esters treated with unhindered LABs provide tertiary amines in excellent yield. Reduction to the corresponding alkane is achieved using a hindered LAB reagent or by forming the highly reactive Super-Hydride reagent in situ using LAB and a catalytic amount of triethylborane. The reduction methodology disclosed herein is a safe and convenient alternative to existing synthetic methods. [reaction: see text]