Chemoselective reductive amination of aldehydes and ketones by dibutylchlorotin Hydride-HMPA complex

Reductive amination of various aldehydes and ketones has been performed eff ectively by pentacoordinate chloro-substituted tin hydride complex, Bu2SnCl H-HMPA. The tin reagent worked particularly well for the case using weakly basic aromatic amines as starting substrates. Stoichiometric amounts of a s ubstrate and a reducing agent were adequate fur the reaction. The Sn-Cl bon d in the complex plays an important role for both stops of imine formation and subsequent reduction. Highly chemoselective reduction of carbonyls coul d be achieved regardless of other functionalities such as halogen, carbon-c arbon double bond and hydroxyl groups in the starting carbonyls and amines.