Bis(triphenylphosphine)copper(I) cyanoborohydride dimer is selective, mild reducing reagent for the conversion of acid chlorides to aldehydes under neutral conditions, and reduction of aldehydes and ketones to alcohols in acidic media.
Bis(triphenylphosphine)copper(I) cyanoborohydride dimer is prepared from treating Copper(II) Sulfate or Copper(I) Chloride sequentially with excess Triphenylphosphine and Sodium Cyanoborohydride in ethanol. The reagent is synthesized in an analogous manner to those described for the preparation of the corresponding BH4 derivative.
