Amide Bond Formation in Organic Synthesis

Amide bonds are among the most ubiquitous linkages in natural products, pharmaceuticals and advanced materials. Traditional approaches rely on stoichiometric coupling reagents to activate carboxylic acids for reaction with amines, often generating significant chemical waste. Recent decades have seen the emergence of catalytic protocols that employ transition metals, organocatalysts or alternative activation modes to achieve greater atom economy, functional‐group tolerance and sustainability. These advances encompass reductive amidation, carbonylation, Umpolung strategies and electrochemical methods, all of which seek to streamline synthesis, reduce by‐products and enable late‐stage functionalisation of complex molecules. Such innovations hold global significance for drug discovery, agrochemicals and polymer science, linking mechanistic insight with practical applications.

Research from Nature Portfolio

Recent studies have introduced a heterogeneous nickel‐based nanocatalyst capable of direct reductive amidation of esters with nitro compounds under additive‐free conditions. This method delivers a wide range of amides with high step economy and broad functional‐group compatibility, and has been applied to the synthesis of small‐molecule drugs and late‐stage modification of bioactive scaffolds. Another advance employs palladium‐catalysed carbonylation to construct non‐symmetrical diamides and amido‐esters from propargylic precursors, proceeding through a cascade of allenoic and allylic intermediates. This protocol affords over a hundred heterobifunctional compounds, many of which bear pharmaceutical relevance. A third development uses a triplet synergistic catalysis combining iron, phosphorus redox catalysts and photoredox activation to enact an Umpolung amidation of carboxylic acids with nitroarenes or nitroalkanes, delivering diverse amides with excellent regioselectivity and minimal by‐product formation.

Amide Bond Formation in Organic Synthesis publication trend

The graph below shows the total number of articles in amide bond formation in organic synthesis across all publications each year (not limited to Nature Index journals).

Technical terms

Amide bond: A covalent linkage between a carbonyl carbon and an amine nitrogen, fundamental in proteins, polymers and pharmaceuticals.

Coupling reagent: A stoichiometric activator used to convert a carboxylic acid into a more electrophilic intermediate for reaction with an amine.

Reductive amidation: A process in which esters or nitro compounds are converted directly into amides using reducing conditions and catalysts.

Carbonylation: A catalytic reaction that introduces a carbonyl group (often from CO) into a substrate, enabling formation of amides or esters.

Umpolung amidation: A strategy that reverses the normal polarity of functional groups, allowing carboxylic acids to act as electrophiles toward typically nucleophilic partners.

Photoredox catalysis: The use of light‐activated catalysts to mediate single‐electron transfers, enabling unconventional bond‐forming pathways.

Electrosynthesis: A technique employing electrical current to drive redox reactions in organic synthesis, often minimising chemical waste.

References

1. Streamlining the synthesis of amides using Nickel-based nanocatalysts. Nature Communications (2023).
2. Synthesis of non-equivalent diamides and amido-esters via Pd-catalysed carbonylation. Nature Synthesis (2023).
3. Site-specific Umpolung amidation of carboxylic acids via triplet synergistic catalysis. Nature Communications (2021).
4. Borate esters: Simple catalysts for the sustainable synthesis of complex amides. Science Advances (2017).
5. The preparation and applications of amides using electrosynthesis. Green Chemistry (2020).
6. Mechanistic insights into boron-catalysed direct amidation reactions. Chemical Science (2018).