Eusebio Juaristi has spent a career thinking about molecules in 3D

Eusebio Juaristi stands up in the middle of our conversation and returns with a bag full of colorful plastic sticks. By fitting together the sticks with little joints, he constructs 3D molecular models that illustrate some of his work—work that most chemists have heard of even if they wouldn’t recognize Juaristi’s name.

Juaristi, a distinguished professor emeritus at the Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav) Mexico City, is one of the most cited chemists in Latin America and has received almost every national award Mexico can give. “He is a rock star,” says Rodrigo Patiño, a researcher at Cinvestav Mérida in Yucatán, Mexico. Patiño has known the veteran researcher since 1995, when Patiño began research for his PhD in the laboratory next door to Juaristi’s.

Some colleagues consider Juaristi one of the leading experts on the anomeric effect. A basic tenet in conformational analysis dictates that substituents in six-membered rings prefer to position themselves equatorially, or in the same plane as the ring. The anomeric effect refers to cases where substituents instead position themselves axially, jutting out from the plane of the ring.

Using the molecular models, he shows how his research team discovered that an organic heterocyclic molecule adopted a conformation that seemed impossible. Its bulky substituent was hovering above the ring rather than alongside it. “We had evidence for an unprecedented, strong anomeric interaction,” he explains (J. Org. Chem. 1982, DOI: 10.1021/jo00146a048).

But like other fundamental principles governing molecular physics, “the anomeric effect, for example, is not a topic that attracts much of the spotlight,” he says.

As he uses the molecular model kit to tell the story of discovery, he begins to reminisce about how the kit has a story of its own. When he was an undergraduate in 1970, he attended a short course on stereochemistry, where he met Ernest L. Eliel, one of the creators of conformational analysis. “He noticed how intrigued I was by his Fieser molecular models, and he gave them to me as a gift. Fifty-four years later, I still use them,” Juaristi says, referring to the plastic sticks dispersed on the table. In 1972, he went to the University of North Carolina at Chapel Hill to pursue his PhD under the supervision of Eliel.

In 1979, after finishing a postdoc at the diagnostic division of Syntex in Palo Alto, California, he received an invitation to join the chemistry department at Cinvestav Mexico City. “By then I had decided I wanted to have my own research group,” he says. “I also concluded that my potential contribution as a teacher and as a researcher would have a much greater impact in Mexico.”

C. Dale Poulter, former editor in chief of the Journal of Organic Chemistry, considers Juaristi’s work in conformational analysis, enantioselective synthesis of β-amino acids, and asymmetric organocatalysis outstanding. But Poulter particularly credits Juaristi’s role in the development of the field of physical organic chemistry on the continent, as Juaristi was a trailblazer in establishing a rigorous program for training students in Mexico in the late 1970s. “The impact of his work has spread throughout Latin America as his students have moved on to other countries to establish their own programs,” he says.

In recent years, Juaristi has been one of the most determined promoters of green chemistry in Mexico. He aims to develop products and processes that reduce the release of environmentally harmful waste. He is particularly interested in using high-speed ball milling to develop solvent-free conditions for catalytic processes. “We are pioneers in applying mechanochemistry in peptide synthesis, as well as asymmetric organocatalysis through mechanochemical activation.”

Despite Patiño’s admiration for Juaristi, the veteran researcher is mostly unknown to chemists outside Mexico. Juaristi’s colleagues say one explanation could be that fundamental science like his doesn’t get enough press. But Guillermo Delgado Lamas, a former president of the Chemical Society of Mexico, also points to the strong skepticism toward research that comes from anywhere other than the famous research centers in Europe or the US.

Juaristi agrees there tends to be a bias, especially against young scientists in Latin America. “When you write a paper, some colleagues prefer to cite the work done in institutions in the US, Europe, or Japan,” he says.

While working in Mexico over the past 45 years, Juaristi has noted many changes, some good, some bad. Overall, he commends the advancements he’s finding across Latin America. “The number of students, chemistry departments, graduate programs in chemistry—not only in Mexico but in other countries like Brazil, Argentina, and Colombia—is something to be proud of,” he says.

But scientists face new challenges with governments skeptical of the importance of education and research. Consequent cuts of scholarships and grants have recently happened in Brazil, Mexico, and Argentina. “The last 6 years have been very difficult because the current government in Mexico does not support science,” Juaristi says.

Juaristi, like many of his colleagues, has lost his grant from the Mexican science council. The president-elect, Claudia Sheinbaum, has promised to revert the neglect, although Juaristi is skeptical that the “available financial resources will be sufficient to honor this promise.”

Despite the troubles, Juaristi sees a bright future for his laboratory. He recalls a comment from Nobel laureate Herbert Brown that made an impression on him. Brown had visited Mexico in the 1990s, and after his lecture Brown said his best chemistry efforts came after winning the prize, well into his 60s. The comment now makes complete sense for Juaristi: “There is no reason to stop. I am starting new, exciting projects; I have many ideas; I am just 73 years old.”