Recent Developments in Amide Synthesis: Direct Amidation of Carboxylic Acids and Transamidation Reactions

Abstract

The synthesis of amides is of huge importance in a wide variety of industrial and academic fields and is of particular significance in the synthesis of pharmaceuticals. Many of the well established methods for amide synthesis involve reagents that are difficult to handle and lead to the generation of large quantities of waste products. As a consequence, there has been a considerable amount of interest in the development of new approaches to amide synthesis. Over the past few years a wide range of new reagents and catalysts for direct amidation of carboxylic acids have been reported. In addition, the interconversion of amide derivatives through transamidation is emerging as a potential alternative strategy for accessing certain amides. This microreview covers recent developments in the direct amidation of carboxylic acids and the interconversion of amides through transamidation. The advantages and disadvantages of the various methods are discussed, as well as the possible mechanisms of the reactions.

Synthetic Applications of the Parkins Nitrile Hydration Catalyst [PtH{(PMe2O)2H}(PMe2OH)]: A Review

“…a process of great relevance in view of the broad industrial, synthetic, biological, and pharmacological applications of corresponding primary amide products [4][5][6]. The conversion of nitriles into amides by conventional acid/base strategies usually requires harsh conditions and remains impractical for most purposes due to yield and selectivity issues, since these classical methods are frequently unable to control the over-hydrolysis of the primary amide product [7,8].…”

Selective Absorption of Hydrophobic Cations in Nanostructured Porous Materials from Crosslinked Hydrogen‐Bonded Columnar Liquid Crystals

“…This thermotropic property is ideal for our application to form a nanostructured porous material by orthogonal selfassembly with a polyamine, because at elevated temperatures the ionic interactions between a carboxylate and ammonium salt could form a covalent amide bond. [ 49 ] This phase behavior was also confi rmed by XRD, and the highly birefringent LC phase was assigned Col hex , based on the representative q -ratios of 1:√3:2 and a diffuse signal at 14.3 nm −1 of the fl exible alkyl tails. Furthermore, from the XRD an intercolumnar distance of 1.94 nm was found, with an interdisc distance of 0.35 nm which is typical for LC BTA derivatives, and a density of 1.08 g cm −3 .…”

A One-Pot, fast, and efficient amidation of carboxylic acids, α-amino acids and sulfonic acids using pph3/n-chlorobenzotriazole system

“…After finding the optimal reaction conditions, we studied the methodology with an array of commercially available aromatic and aliphatic carboxylic acids with benzylamine (Table 3, entries [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In comparison, aromatic carboxylic acids with electron deficient substituents were successfully reacted with benzylamine very rapidly than electron-rich aromatic carboxylic acids (e.g.…”

“…Direct condensation of carboxylic and sulfonic acids with amines has been used for the synthesis of amides and sulfonamides. 5 High temperatures requirements and harsh reaction conditions have limited these methods. The most common method for the preparation of amides and sulfonamides is the reaction of acyl and sulfonyl halides with ammonia, primary or secondary amines in the presence of a base.…”