AMINOBOROHYDRIDES .9. SELECTIVE REDUCTIONS OF ALDEHYDES, KETONES, ESTERS, AND EPOXIDES IN THE PRESENCE OF A NITRILE USING LITHIUM N,N-DIALKYLAMINOBOROHYDRIDES

A series of competitive reductions of several functional groups was ca rried out in the presence of aromatic and aliphatic nitriles using lit hium N,N-dimethylaminoborohydride (LiMe(2)NBH(3)) or Lithium Pyrrolidi noborohydride (LiPyrrBH(3)) as the reducing agents. Both LiMe(2)NBH(3) and LiPyrrBH(3) cleanly and quantitatively reduced aldehydes, ketones , esters, and epoxides in the presence of the nitriles to give the cor responding reduction products in yields ranging from 85 to 98%. In no case was the nitrile reduced: no products arising from the reduction o f nitriles were detected by GC analysis. Two difunctional nitriles wer e also reduced to give complete reduction of the more active functiona l group with no reduction of the nitrile. (C) 1997, Elsevier Science L td. All rights reserved.