Reductive amination agents: comparison of Na(CN)BH3 and Si-CBH

Reductive amination is a chemical reaction commonly employed by organic chemists in academics and the pharmaceutical industry. In this reaction a carbonyl group is converted to an amine via an imine intermediate, the formation of which is rate limiting. A major reagent necessary for the completion of this reaction is a hydride source, commonly sodium cyanoborohydride (Na(CN)BH3). The objective of this research was to compare the efficacy of Na(CN)BH3 with silica-bound cyanoborohydride (Si-CBH) as hydride sources in reductive amination reactions. Work has shown that reactions employing Si-CBH as a hydride source showed significant improvement, exhibiting an average percent conversion 25% greater than reactions using Na(CN)BH3. (C) 2009 Elsevier Ltd. All rights reserved.