Leo A. Paquette

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1934 – 2019

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Leo A. Paquette was born in Worcester, Massachusetts, on July 15, 1934. He attended the College of the Holy Cross in his home town and graduated with a degree in chemistry, magna cum laude, in 1956. He attended the Massachusetts Institute of Technology where he received his Ph.D. in organic chemistry in 1959 under the tutelage of Norman Nelson. After graduation, Leo was employed as a research associate at the Upjohn Company in Michigan until he joined the chemistry faculty at the Ohio State University in 1963. He was promoted to full professor in 1969, Kimberly Professor in 1981, and Distinguished University Professor in 1987. During his academic career, “Doc”, as he was affectionately called by his students, mentored approximately 150 doctoral students, 300 postdoctoral associates, and countless masters students and undergraduates.

Leo served on the editorial boards of a number of chemistry journals, including Organic Reactions from 1979-2008, where he was the Editor-in-Chief from 1989-1999. During his reign at Organic Reactions, he was responsible for Volumes 38 – 55 and a significant expansion of the series. He was the founding Editor of the Encyclopedia of Reagents for Organic Synthesis (EROS) which is now known in electronic format as e-EROS. Leo also served on advisory committees at the NIH and NSF and was a consultant for Eli Lilly for many years. Leo was the recipient of a number of honors and awards including an Alfred P. Sloan Fellowship (1965), a Guggenheim Fellowship (1976) and Arthur C. Cope Scholar (1987). In 1984 he was awarded the ACS Award for Creative Work in Synthetic Organic Chemistry and was elected to the National Academy of Sciences that same year.

Leo’s research interests encompassed a broad range of organic chemistry: the study and synthesis of heterocycles, metal-catalyzed strained ring chemistry, multiple syntheses of structurally-novel hydrocarbons, the development of numerous synthetic methods, the synthesis of complex natural products, synthetic applications of anion-assisted oxy-Cope rearrangements, and more. Some specifics are worth highlighting.

Throughout his entire career he was fascinated by the interactions of conjugated -electron systems. In his early years this manifested itself, inter alia, in studies on azepine and oxepin. Subsequently, he studied fluxional systems, such as bullvalene, semibullvalene and their aza-counterparts. He also made major contributions to our understanding of neutral and charged aromaticity (e.g., cyclooctatetraene dications) and homoaromaticity (e.g., elassovalene, triquinacenes and propellanes). Many of these systems presented major synthetic challenges and Leo and his coworkers often used Ramberg Backlund reactions to install olefin linkages that were hard to prepare by other means. He also used chloroisocyanate reactions (e.g., with Dewar benzene derivatives) and di--methane rearrangements as novel approaches for preparing many of the systems discussed above.

By the 1980s Leo’s interests turned to the synthesis of natural products. Amongst his favorite targets were triquinane natural products. His early achievements included pentalene, pentalenolactone and modhephene in the early 1980s and progressed to coriolin and hypnophilin in 2002 with many other successes in between. He used an anion-assisted oxy-Cope rearrangement, followed by a dihydroxylation/pinacol rearrangement to prepare the complex taxane ring structure (e.g., taxusin). He also employed the anion-assisted oxy-Cope rearrangements as the key steps in his synthesis of vulgarolide and cerorubenic acid. Ultimately the Paquette research group completed well over 50 total syntheses.

Leo is best known for his synthesis of the Platonic solid dodecahedrane in 1982, which was completed after a decade of research. Although the original rationale for preparing this exotic molecule was inspired by the use of an adamantylamine (e.g., memantine) as an NMDA calcium channel blocker for treating Alzheimer’s disease, it ultimately became his personal quest to prepare a beautifully symmetric target molecule for much the same reason that many adventurers attempted to climb Mount Everest – because it’s there. This work is generally recognized as a significant achievement in organic synthesis and is illustrative of his persitence, creativity, and devotion to science.

Leo was very demanding of his students and post-doctoral associates but he personally set the standard when it came to devotion and hard work. He authored over 1300 peer-reviewed papers, 38 book chapters, and 17 books. He also lectured at various institutions both domestically and internationally, and was noted for his excellent seminars. An added benefit of Leo’s travels was that he brought home exotic beers from the places he visited, and offered them to his students at his annual Christmas party. His son, Ron, would add them to his beer can collection that totaled over 2000 different beers from around the world!

I (MW) knew Leo for over 50 years. I showed up in his lab for the first time as an NSF visiting summer student in 1968 and learned how to do recrystallizations for elemental analysis from the master himself. When my academic career was interrupted for military service, Leo kept in touch with me during those two years by sending me preprints of various publications he had underway. My years at Ohio State working with “Doc” are filled with only good memories.

In my case (DL), Leo did more to shape my professional development than any other single individual. While there was no doubt that he was demanding, the work ethic that he instilled in all of us who worked in his research group has served us well in our careers.

Leo’s competitive side also showed up outside of the lab. He was an overly enthusiastic participant on our softball and basketball teams! Leo was a big fan of the Ohio State football program. Game day was one of the few legitimate reason for not being in the lab!

Leo passed away on January 21, 2019 after a long battle with Parkinson’s Disease. He was married for 61 years to a wonderful woman named Estelle and they had five children together (Ronald, Donna, Susan, Linda and Lisa). They also have 13 grandchildren and 5 great-grandchildren.

Leo Paquette was an excellent mentor and a good friend over the years. May he rest in peace.

Matthew Wyvratt (Ph.D., 1976), Dennis Liotta (Postdoc, 1974-1976)