Amide bond formation strategies: latest advances on a dateless transformation

The synthesis of amides remains one of the most important transformations and it is one of the more frequently performed reactions. In the pharmaceutical industry, the formation of the amide group is pivotal and among the more important transformations in the design of the synthetic plan. This review presents an overview of only very recent contributions, published in the last three years, to highlight the latest progress in this "dateless" reaction, with a special focus on metal-free methodologies. New, more efficient and/or greener stoichiometric methods, as well as catalytic strategies, have been discussed, either for the "classic" coupling approach between an amine and a carboxylic acid (or its activated equivalent) or for more innovative approaches, mainly involving oxidation procedures to generate amides starting from amines.