The amide functionality is found in a wide variety of biological and synthetic structures such as proteins, polymers, pesticides and pharmaceuticals. Due to the fact that synthetic amides are still mainly produced by the aid of coupling reagents with poor atom-economy, the direct catalytic formation of amides from carboxylic acids and amines has become a field of emerging importance. A general, efficient and selective catalytic method for this transformation would meet well with the increasing criterias for green 10 chemistry. This review covers catalytic and synthetically relevant methods for direct condensation of carboxylic acids and amines. A comprehensive overview of homogeneous and heterogeneous catalytic methods is presented, covering biocatalysis, Lewis acid catalysts based on boron and metals as well an assortment of other types of catalysts.

Amidst the green: A green, mild and effective protocol for the direct formation of secondary and tertiary amides from non‐activated carboxylic acids and amines in good to excellent yields by employing ZrCl4 as the catalyst is presented (see scheme). The amide coupling protocol proved to be suitable for scaled up syntheses, and the mild reaction conditions conserve the enantiopurity of chiral starting materials.

The arylation of secondary acyclic amides has been achieved with diaryliodonium salts under mild and metal-free conditions. The methodology has a wide scope, allows synthesis of tertiary amides with highly congested aryl moieties and avoids the regioselectivity problems observed in reactions with (diacetoxyiodo)benzene.

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