Morten Meldal

Morten Meldal
Born	16 01, 1954
Birthplace	Denmark
Nationality	Danish
Occupation	Chemist, academic
Employer	University of Copenhagen
Known for	Click chemistry, copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC)
Awards	Nobel Prize in Chemistry (2022)

Morten Meldal (born 16 January 1954) is a Danish chemist and professor at the University of Copenhagen who was awarded the Nobel Prize in Chemistry in 2022, jointly with Carolyn R. Bertozzi and K. Barry Sharpless, for their foundational work on the development of click chemistry and bioorthogonal chemistry. Meldal's contributions center on his independent discovery of the copper(I)-catalyzed azide–alkyne cycloaddition reaction, a reaction that allows molecular building blocks to snap together with high efficiency and selectivity, much like the clicking together of two pieces of a belt buckle. His work transformed the landscape of synthetic chemistry and opened broad applications in pharmaceutical development, materials science, and the life sciences. A career organic chemist with deep roots in the Danish academic tradition, Meldal has been an outspoken advocate for public investment in education and research, crediting Denmark's high-tax, high-investment model with fostering the kind of scientific environment in which discoveries like click chemistry could emerge.

Early Life

Morten Meldal was born on 16 January 1954 in Denmark. From an early age, Meldal developed an interest in the natural sciences, a trajectory that would eventually lead him to chemistry. In interviews following his Nobel Prize award, Meldal has spoken about the importance of fostering curiosity and a love for learning from childhood, themes he has continued to emphasize in public lectures and appearances throughout his career.

Meldal grew up in Denmark during a period when the country's welfare state and public education system were expanding. He has attributed part of his scientific success to this environment, noting that Denmark's societal investment in education and research created conditions that allowed young people from a range of backgrounds to pursue academic careers in the sciences. In a 2025 interview with Times Higher Education, Meldal spoke about the Danish model, arguing that the country's willingness to invest in public institutions had yielded significant returns, including in the pharmaceutical sector. He pointed to the success of Denmark's weight-loss drug industry as a direct dividend of this approach.

Details about Meldal's family background and personal upbringing prior to his university education are not extensively documented in publicly available sources. What is clear from his own accounts is that his formative years in Denmark instilled in him a commitment to public science and education that has remained central to his worldview throughout his career.

Education

Meldal pursued his higher education in Denmark, training in chemistry and earning his doctoral degree in the field. He has been associated with the University of Copenhagen for much of his academic career, where he eventually rose to the rank of professor. His academic training provided him with a strong foundation in organic chemistry and peptide synthesis, areas that would prove essential to his later work on click chemistry and combinatorial chemistry.

In his public lectures and interviews, Meldal has consistently emphasized the role that a strong educational foundation plays in enabling scientific discovery. Speaking at an online lecture in 2025, he stated that investing in education yields the greatest return for society, advocating for approaches that make education enjoyable and accessible from an early age.

Career

Early Research and Peptide Chemistry

Meldal's early career was rooted in organic chemistry, with a particular focus on solid-phase peptide synthesis and combinatorial chemistry. Working at the University of Copenhagen, he developed methods for creating and screening large libraries of chemical compounds — techniques that are fundamental to modern drug discovery. His expertise in synthesizing complex molecules on solid supports gave him an intimate understanding of the challenges involved in building molecular architectures, and it was this experience that ultimately led him toward the concept of click chemistry.

In the course of his work on combinatorial chemistry, Meldal became acutely aware of the limitations of traditional organic synthesis. Many reactions in classical chemistry are inefficient, producing unwanted byproducts and requiring laborious purification steps. The search for reactions that were reliable, selective, and high-yielding became a central preoccupation of his research. This quest for chemical efficiency would converge with parallel efforts by other chemists, most notably K. Barry Sharpless, who in 2001 articulated the concept of "click chemistry" — a philosophy of chemistry that emphasized modular, wide-in-scope, high-yielding reactions that generate only inoffensive byproducts.

Discovery of the CuAAC Reaction

Meldal's most consequential scientific contribution came with his independent discovery of the copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. This reaction, in which an organic azide reacts with a terminal alkyne in the presence of a copper(I) catalyst to form a 1,2,3-triazole, represented a transformative advance in synthetic chemistry. The reaction proceeds with remarkable selectivity, producing only one product (the 1,4-disubstituted triazole), and it works reliably across a wide range of conditions and substrates.

The discovery was made independently and approximately simultaneously by Meldal and by Sharpless's research group. Meldal's work was carried out in the context of solid-phase peptide chemistry, where he was exploring new methods for linking molecular fragments together. He found that the copper-catalyzed reaction between azides and alkynes was extraordinarily efficient and selective — qualities that made it an ideal "click" reaction.

In an interview with El País, Meldal described the origins of the discovery, noting that the idea came from an unexpected observation in the laboratory. He characterized the moment of discovery as "staggering," underscoring the serendipitous nature of many scientific breakthroughs.

The CuAAC reaction quickly became one of the most widely used reactions in modern chemistry. Its reliability and versatility made it a cornerstone of click chemistry, and it found applications across a vast range of disciplines, from drug development to polymer science to bioconjugation. The reaction allowed chemists to assemble complex molecules from simpler building blocks with unprecedented ease, fundamentally changing the way synthetic chemistry was practiced.

Click Chemistry and Its Applications

Click chemistry, as a broader framework, rests on the principle that molecular construction should be simple, efficient, and reliable. The CuAAC reaction discovered by Meldal became the prototypical example of a click reaction — a reaction that is fast, selective, produces minimal waste, and works under mild conditions. The concept transformed multiple fields of science and technology.

In pharmaceutical research, click chemistry enabled the rapid assembly of drug candidates and the efficient modification of biologically active molecules. Researchers could use the CuAAC reaction to attach fluorescent tags, drug payloads, or targeting groups to biomolecules with precision. This capability proved especially valuable in the development of antibody-drug conjugates, targeted therapies, and diagnostic tools.

Meldal has expressed optimism about the future applications of click chemistry in medicine. In his 2023 interview with El País, he stated that click chemistry would help in the fight against cancer and Alzheimer's disease, pointing to the ability of click reactions to create precisely defined molecular tools for diagnosing and treating these conditions. He described how the modular nature of click chemistry allows scientists to construct molecules that can interact with specific biological targets, opening new avenues for precision medicine.

Beyond medicine, the CuAAC reaction and click chemistry more broadly have found applications in materials science, where they are used to create new polymers, coatings, and functional materials. In chemical biology, click reactions are employed to label and track biomolecules inside living cells, providing researchers with powerful tools for studying biological processes at the molecular level.

Work at the University of Copenhagen

Throughout his career, Meldal has been based at the University of Copenhagen, where he has served as a professor and led a research group focused on organic chemistry, combinatorial chemistry, and catalysis. His laboratory has been a training ground for numerous doctoral students and postdoctoral researchers, many of whom have gone on to establish their own research programs.

At Copenhagen, Meldal's group continued to develop new click reactions and to explore the applications of these reactions in areas such as drug discovery and bioconjugation. The group's work has contributed to a deeper understanding of how copper catalysts promote the azide–alkyne cycloaddition and has led to the development of improved reaction conditions and new catalytic systems.

Meldal has also been active in promoting interdisciplinary research, recognizing that the applications of click chemistry span traditional disciplinary boundaries. His work has brought together organic chemists, biochemists, materials scientists, and pharmacologists, fostering collaborations that have expanded the reach and impact of click chemistry.

Advocacy for Education and Public Investment in Science

In the years following his Nobel Prize, Meldal has become an increasingly prominent public voice on the relationship between education, public investment, and scientific progress. In a 2025 interview with Times Higher Education, he argued that Denmark's success as a "science superpower" — including the pharmaceutical industry's development of blockbuster weight-loss drugs — was a direct consequence of the country's high-tax, high-investment economic model. He urged citizens to "pay your taxes with pride," arguing that public investment in universities and research institutions generates returns that benefit all of society.

Meldal has carried this message to international audiences as well. Speaking at an online lecture organized in India in 2025, he emphasized that investment in education yields the highest returns for society and advocated for making education an enjoyable and engaging experience for young people. He stressed the importance of cultivating a love for learning from early childhood, arguing that this is the foundation upon which scientific progress is built.

These public interventions reflect Meldal's view that scientific discovery does not occur in a vacuum but is deeply embedded in the social and economic structures that support it. His advocacy has positioned him as a notable figure not only in chemistry but also in broader public debates about science policy and education.

Personal Life

Meldal has maintained a relatively private personal life. He is based in Denmark and has continued his association with the University of Copenhagen following his receipt of the Nobel Prize. In his Nobel Week interview in December 2022, Meldal reflected on his career and the significance of the Nobel Prize, offering insights into his scientific philosophy and his views on the future of chemistry.

Meldal has been described as a thoughtful and engaged communicator of science. Following his Nobel Prize, he has participated in numerous public events, including a conversation at the Nobel Prize Museum in Stockholm on the topic of click chemistry, where he discussed the challenges and rewards of building molecules and the philosophy behind making chemistry "easier."

His public remarks consistently return to themes of curiosity, education, and the social responsibility of scientists to contribute to the public good. He has expressed a deep appreciation for the Danish academic tradition and the collaborative culture that characterizes Scandinavian science.

Recognition

Nobel Prize in Chemistry (2022)

On 5 October 2022, the Royal Swedish Academy of Sciences announced that the Nobel Prize in Chemistry for that year would be awarded jointly to Carolyn R. Bertozzi, Morten Meldal, and K. Barry Sharpless "for the development of click chemistry and bioorthogonal chemistry." The prize recognized the trio's work in creating a new framework for building molecules that was simpler, more efficient, and more reliable than traditional synthetic approaches.

Meldal was cited specifically for his independent discovery of the CuAAC reaction, which the Nobel Committee identified as the paradigmatic click reaction — the reaction that best exemplified the click chemistry philosophy articulated by Sharpless. The Committee noted that the CuAAC reaction had become one of the most used reactions in modern chemistry, with applications spanning drug development, materials science, and chemical biology.

The 2022 Nobel Prize in Chemistry was notable in part because it was the second Nobel Prize for Sharpless, who had previously received the 2001 Nobel Prize in Chemistry for his work on chirally catalyzed oxidation reactions. Meldal's recognition alongside such a distinguished co-laureate underscored the significance and independence of his contribution to the field.

Profile in the Proceedings of the National Academy of Sciences

In August 2023, the Proceedings of the National Academy of Sciences (PNAS) published a joint profile of the three 2022 Nobel laureates in Chemistry — Bertozzi, Meldal, and Sharpless — detailing their scientific contributions and the impact of their work on the field. The profile provided a comprehensive account of Meldal's research trajectory, from his early work on peptide synthesis to his discovery of the CuAAC reaction and his subsequent contributions to the expansion of click chemistry.

Other Public Engagements

Following his Nobel Prize, Meldal has been invited to speak at events and institutions around the world. In 2025, he appeared at the Nobel Prize Museum in Stockholm for a public conversation about click chemistry, where he discussed the challenges of molecular construction and the philosophy behind his work. He has also delivered lectures in India and other countries, where he has spoken about the relationship between education, public investment, and scientific progress.

Legacy

Meldal's legacy is defined by the transformative impact of the CuAAC reaction and click chemistry on modern science. The reaction he independently discovered has become a standard tool in laboratories around the world, used daily by thousands of researchers in fields ranging from organic chemistry to molecular biology to materials science. Its simplicity, reliability, and versatility have made it one of the most important chemical reactions developed in the late twentieth and early twenty-first centuries.

The broader concept of click chemistry, to which Meldal's work is central, has shifted the philosophy of chemical synthesis. Rather than pursuing complex and often unpredictable reactions, chemists now have access to a toolkit of modular, efficient reactions that allow them to build complex molecular architectures from simple, readily available components. This shift has accelerated the pace of discovery in drug development, diagnostics, and materials design.

Meldal's optimism about the future applications of click chemistry — particularly in medicine — has been echoed by researchers worldwide. His prediction that click chemistry will contribute to the fight against cancer and Alzheimer's disease reflects the growing body of research using click reactions to develop targeted therapies, diagnostic agents, and molecular probes for studying disease mechanisms.

Beyond his scientific contributions, Meldal's public advocacy for education and science policy has extended his influence beyond the laboratory. His insistence that scientific progress depends on broad societal investment in education and research institutions has resonated in policy discussions in Denmark and internationally. By linking his personal success to the Danish model of public investment, Meldal has offered a concrete example of how societal choices shape scientific outcomes.

As a professor at the University of Copenhagen, Meldal has also contributed to the training of a new generation of chemists, ensuring that the methods and philosophy of click chemistry continue to evolve and find new applications. His career stands as a demonstration of how fundamental research in organic chemistry can have far-reaching and transformative consequences for science and society.