Ammonia-borane as a Catalyst for the Direct Amidation of Carboxylic Acids
P. Veeraraghavan Ramachandran, Henry J. Hamann
Abstract
Ammonia-borane serves as an efficient substoichiometric (10%) precatalyst for the direct amidation of both aromatic and aliphatic carboxylic acids. In situ generation of amine-boranes precedes the amidation and, unlike the amidation with stoichiometric amine-boranes, this process is facile with 1 equiv of the acid. This methodology has high functional group tolerance and chromatography-free purification but is not amenable for esterification. The latter feature has been exploited to prepare hydroxyl- and thiol-containing amides.
Topics & Concepts
ChemistryBoranesAmine gas treatingAmmonia boraneCatalysisBoraneAmmoniaOrganic chemistryStoichiometryFunctional groupPrimary (astronomy)Combinatorial chemistryBoronAstronomyPolymerPhysicsHydrogen productionChemical Synthesis and AnalysisChemical Synthesis and ReactionsSynthetic Organic Chemistry Methods