Ryoji Noyori

Ryoji Noyori
Born	03 09, 1938
Birthplace	Kobe, Japan
Nationality	Japanese
Occupation	Chemist, academic administrator
Known for	Asymmetric hydrogenation, chiral molecular catalysts
Education	Kyoto University (Ph.D.)
Awards	Nobel Prize in Chemistry (2001)

Ryoji Noyori (野依 良治, born September 3, 1938) is a Japanese chemist whose pioneering work on asymmetric hydrogenation and chiral molecular catalysts transformed the field of synthetic organic chemistry. In 2001, he was awarded the Nobel Prize in Chemistry, shared with William S. Knowles and K. Barry Sharpless, for his research on chirally catalyzed hydrogenation reactions — work that provided chemists with extraordinarily efficient tools for constructing single-enantiomer molecules essential to pharmaceuticals, agrochemicals, and fragrances. Beyond the laboratory, Noyori served for more than a decade as president of RIKEN, Japan's largest and most prestigious network of basic-research laboratories, a tenure that ended amid institutional controversy in 2015. His scientific contributions, particularly in the development of BINAP-ruthenium catalysts, established foundational principles in molecular catalysis that continue to influence chemical research and industrial practice worldwide.

Early Life

Ryoji Noyori was born on September 3, 1938, in Kobe, Japan. Growing up in a country rebuilding from the devastation of the Second World War, Noyori developed an early interest in science. His fascination with chemistry was reportedly sparked during his youth, and he pursued this interest through his formal education in Japan's university system.

Noyori came of age during a period of rapid scientific and economic development in post-war Japan, when the country was investing heavily in scientific research and technological advancement. The environment fostered a generation of Japanese scientists who would go on to make significant contributions across multiple disciplines.

Education

Noyori pursued his higher education at Kyoto University, one of Japan's most distinguished academic institutions, where he studied chemistry. He obtained his doctoral degree from Kyoto University, conducting research that laid the groundwork for his later contributions to asymmetric synthesis. Kyoto University had a strong tradition in organic chemistry, and Noyori's training there exposed him to rigorous approaches in synthetic methodology and catalysis that would define his career.

Career

Asymmetric Hydrogenation and Chiral Catalysis

Noyori's most significant scientific contributions centered on the development of chiral molecular catalysts for asymmetric hydrogenation. Asymmetric hydrogenation is a chemical process that uses inexpensive, clean hydrogen gas together with a very small amount of a chiral molecular catalyst to produce single-enantiomer products — molecules that exist in only one of two possible mirror-image forms. This methodology represents one of the most powerful approaches available to synthetic chemists for generating optically active compounds.

The significance of chirality — the property by which a molecule and its mirror image are non-superimposable — cannot be overstated in fields such as pharmaceutical science. The two enantiomers of a chiral drug molecule can have vastly different biological effects: one may be therapeutically beneficial while the other is inactive or even harmful. Noyori's work provided chemists with practical, efficient tools for producing the desired enantiomer with high selectivity.

Central to Noyori's achievements was the development of BINAP (2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) ligands and their use in transition metal catalysis. BINAP-ruthenium complexes, in particular, proved to be remarkably versatile and effective catalysts for a wide range of asymmetric hydrogenation reactions. These catalysts could convert prochiral substrates into chiral products with exceptionally high enantiomeric excess, often exceeding 99 percent. The architectural and functional engineering of these chiral molecular catalysts represented a major advance in catalyst design, combining structural elegance with practical efficiency.

Noyori's research demonstrated that the three-dimensional architecture of the catalyst — specifically, the spatial arrangement of the chiral ligands around the metal center — was critical to achieving high levels of enantioselectivity. By systematically varying the structural features of the ligands and the metal complexes, Noyori and his collaborators developed a deep understanding of the principles governing molecular recognition in catalytic asymmetric synthesis.

Chiral Metal Complexes as Discriminating Molecular Catalysts

In a landmark publication in the journal Science in 1990, Noyori described the use of chiral metal complexes as discriminating molecular catalysts. He situated this work within the broader context of molecular recognition, which was gaining increasing importance in the biological and physical sciences as well as in the emerging technologies of molecular electronics and sensor design.

This publication outlined how chiral metal complexes could serve as highly selective catalysts capable of distinguishing between the two faces of a prochiral substrate, directing the addition of hydrogen (or other reagents) to produce predominantly one enantiomer of the product. The concept of a catalyst acting as a "discriminating" agent — capable of making fine distinctions at the molecular level — captured the imagination of the synthetic chemistry community and helped to establish asymmetric catalysis as a central theme in modern organic chemistry.

The principles Noyori articulated in this work extended beyond hydrogenation. They provided a conceptual framework for understanding how chiral environments created by metal-ligand complexes could be exploited across a variety of catalytic transformations, including carbon-carbon bond-forming reactions, oxidations, and reductions. This framework influenced the design of new catalytic systems by other research groups around the world.

Contributions to Prostaglandin Synthesis

Another notable area of Noyori's research involved the organic synthesis of prostaglandins, a class of lipid compounds with diverse and important biological functions. Prostaglandins play roles in inflammation, blood flow regulation, and the induction of labor, among other physiological processes. The efficient synthesis of prostaglandins and their analogs was of considerable interest to both academic chemists and the pharmaceutical industry.

Noyori's approach to prostaglandin synthesis demonstrated the power of asymmetric catalysis in constructing complex, biologically relevant molecules. By applying his catalytic methodologies, Noyori developed synthetic routes to prostaglandins that were more efficient and stereoselective than previously available methods. This work was described in a publication in Science that highlighted how advances in organic synthesis could directly benefit biological research by making important molecules more readily accessible.

The prostaglandin work exemplified Noyori's broader philosophy that organic synthesis should not be pursued merely as an intellectual exercise but should serve as a tool for advancing understanding in biology and medicine. His syntheses demonstrated that complex natural products could be prepared in practical quantities using catalytic methods, thereby enabling biological studies that would otherwise be impractical.

Industrial Applications

The practical implications of Noyori's catalytic systems extended well beyond the academic laboratory. Asymmetric hydrogenation using BINAP-metal catalysts was adopted by the chemical and pharmaceutical industries for the large-scale production of enantiomerically pure compounds. One of the most notable industrial applications was the Takasago process for the production of l-menthol, which employed a BINAP-rhodium catalyst to achieve an asymmetric isomerization step on an industrial scale. This process demonstrated that Noyori's catalytic methodology could be translated from laboratory-scale reactions to industrial production, generating thousands of tons of product per year.

The efficiency of Noyori's catalysts was particularly noteworthy. Because asymmetric hydrogenation uses hydrogen gas — an abundant and inexpensive reagent — and requires only catalytic quantities of the chiral metal complex, the process generates minimal waste compared to alternative methods that employ stoichiometric quantities of chiral auxiliaries. This atom economy and environmental compatibility aligned with emerging principles of green chemistry, making Noyori's methods attractive from both economic and environmental perspectives.

Presidency of RIKEN

In 2003, Noyori was appointed president of RIKEN, Japan's foremost comprehensive research institution, which operates a network of basic-research laboratories across multiple scientific disciplines. As president, Noyori oversaw the administration and strategic direction of an organization that employed thousands of researchers and maintained facilities in fields ranging from physics and chemistry to biology and engineering.

Noyori served as RIKEN president for more than a decade, a period during which the institution continued to expand its research portfolio and international collaborations. However, his tenure became overshadowed by a major scientific controversy that erupted in 2014. Researchers at RIKEN published what was initially presented as a breakthrough in stem cell biology — a method for creating stimulus-triggered acquisition of pluripotency (STAP) cells. The findings, published in the journal Nature, attracted worldwide attention but were quickly subjected to intense scrutiny.

An investigation conducted by RIKEN concluded that the lead author of the STAP papers had committed fraudulent acts. The institution's investigation accused the lead writer of taking fraudulent steps in what had been presented as a breakthrough paper. The controversy resulted in the retraction of the papers from Nature and had tragic consequences, including the suicide of a co-author. The scandal raised serious questions about research oversight and integrity at RIKEN.

In March 2015, Noyori announced his intention to step down as RIKEN president. In a statement released by the institution, Noyori indicated he would leave his position after having served since 2003. Reporting by Nature characterized the resignation as coming after a year in which the organization had been embroiled in the STAP cell controversy. The episode marked a difficult conclusion to Noyori's administrative career at RIKEN, though it did not diminish the significance of his scientific contributions.

Recognition

Nobel Prize in Chemistry

Noyori's most prominent recognition came in 2001, when he was awarded the Nobel Prize in Chemistry. He shared the prize with American chemists William S. Knowles and K. Barry Sharpless. Knowles and Noyori were recognized for their work on chirally catalyzed hydrogenation reactions, while Sharpless was cited for his work on chirally catalyzed oxidation reactions. In an interview conducted in December 2001, the three laureates discussed their research and its implications for the field of chemistry.

The Nobel Committee recognized that the work of Noyori and his co-laureates had provided chemists with tools of immense practical value. The ability to perform asymmetric catalysis — to use small quantities of chiral catalysts to convert large amounts of substrate into enantiomerically enriched products — represented a paradigm shift in synthetic chemistry. The recognition underscored the importance of catalysis as a fundamental enabling technology in modern chemistry.

Nagoya Medal of Organic Chemistry

The Nagoya Medal of Organic Chemistry is an award closely associated with the tradition of organic chemistry research at Nagoya University, where Noyori spent much of his career. The award continues to recognize outstanding contributions to organic chemistry by researchers worldwide. The 26th edition of the Nagoya Medal ceremony was scheduled for January 24, 2025, with the gold medal being presented to Professor Alois Fürstner of the Max-Planck-Institut für Kohlenforschung in Germany. The continuation of this award series reflects the enduring legacy of the organic chemistry tradition that Noyori helped to build at Nagoya University.

Other Honors

Over the course of his career, Noyori received numerous additional honors and awards from scientific organizations in Japan and internationally, reflecting the broad impact of his contributions to catalysis and synthetic chemistry. His election to various national academies of science and his receipt of major chemistry prizes further attested to the significance of his work in asymmetric catalysis.

Legacy

Ryoji Noyori's scientific legacy rests primarily on his transformation of asymmetric catalysis from a theoretical possibility into a practical tool of enormous utility. Before the work of Noyori, Knowles, and others in the 1970s through 1990s, the synthesis of enantiomerically pure compounds often required either the use of stoichiometric quantities of expensive chiral reagents or the resolution of racemic mixtures — both inefficient and wasteful processes. Noyori's BINAP-based catalysts demonstrated that a single chiral catalyst molecule could direct the formation of millions of product molecules with high enantioselectivity, fundamentally changing the economics and environmental footprint of chiral synthesis.

The concept of "architectural and functional engineering" of chiral molecular catalysts, as articulated by Noyori, provided a design philosophy that continues to guide catalyst development. Researchers building on Noyori's work have developed new classes of chiral ligands and metal complexes for an ever-expanding range of asymmetric transformations, including those that go beyond hydrogenation to encompass C–C bond formation, C–H activation, and other challenging reactions.

In the pharmaceutical industry, the impact of Noyori's methods has been substantial. The ability to produce single-enantiomer drugs efficiently and at scale has influenced regulatory approaches to drug development, with agencies increasingly requiring that pharmaceutical companies characterize the biological activity of individual enantiomers. The catalytic asymmetric methods pioneered by Noyori provided the synthetic tools needed to meet these regulatory requirements.

Noyori's contributions also intersected with the principles of green chemistry. By enabling reactions that use hydrogen gas — one of the cleanest and most abundant reagents — and that require only trace amounts of catalyst, his methods aligned with the growing emphasis on sustainability in chemical manufacturing. The atom economy inherent in catalytic hydrogenation, compared to methods that generate stoichiometric byproducts, represents a model for environmentally responsible chemical synthesis.

His tenure at RIKEN, though ending on a difficult note due to the STAP cell controversy, also formed part of his broader impact on Japanese science. During his presidency, RIKEN maintained its position as a leading international research institution, and Noyori advocated for the importance of basic research in driving innovation.

The continued vitality of research in asymmetric catalysis, the ongoing industrial application of BINAP-based catalytic systems, and the influence of Noyori's design principles on new generations of catalyst developers all attest to the enduring significance of his contributions to chemistry.