Cobalt-catalyzed Selectively Transfer Hydrogenation Of Nitriles

Amines are very important organic compounds.They are key intermediates in the synthesis of dyes,polymers,numerous pharmaceuticals and natural products.Considering that amine compounds have such important roles,various methods have been developed for the synthesis of amines.For example,amination of aryl halides with Pd,hydroamination of alkenes and alkynes,and direct amination of alcohols with ammonia,all of the above methods can realize the synthesis of amines efficiently.What's more,direct reduction of nitriles to synthesize amines is another important method.Thus,it has attracted widespread attention in recent years to synthesize amines by the reduction of nitriles.In this paper,we focus on using non-precious metal cobalt pincer complexes to realize the transfer hydrogenation of nitriles efficiently under mild conditions.The reaction can proceed with good chemoselectivity,excellent functional group tolerance and catalytic efficiency.I will introduce this paper by three parts:Part ?.Review of the research progress for the synthesis of amines from nitriles in recent years.Part ?.Introduction of research work in this paper.We have developed a series of Cobalt-based pincer complexes successfully.Using NH3BH3 as the hydrogen source can realize the selectively transfer hydrogenation of nitriles to synthesize primary,secondary,and tertiary amines.It was further applied into direct functionalization of pharmaceutical molecules smoothly.Part ?.Preliminary exploration on the reaction mechanism.According to the results of poisoning experiments with phosphines or mercury,we confirmed that this catalytic reaction is a homogeneous process.Meanwhile,we synthesized the N-methyl-substituted cobalt catalysts to study the reaction mechanism of the hydrogen transfer process by control experiments.