Trailblazing Research in Boron Chemistry
A few times in the history of chemistry have new synthetic methods been deemed so important that the originators have been awarded the Nobel Prize.” This is how the magnitude of the research work of the winners of the Nobel Prize in Chemistry for 1979 was emphasized in the Award Ceremony Speech. The England-born American chemist Herbert Charles Brown and the German chemist Georg Wittig had been awarded the Nobel prize that year for the innovative development of boron and phosphorous compounds, respectively, into important reagents for use in organic synthesis.
Choosing to work on the often-ignored element boron, Herbert Brown discovered borohydrides and organoboranes that gave chemists, to quote from the Award Ceremony Speech again, “new and powerful tools for organic synthesis”. Today, organoboranes have become the most versatile reagents in organic synthesis. Brown created over 50 combinations of boron and hydrogen that proved to be invaluable for manufacturing pharmaceuticals and other biological compounds that would have otherwise been difficult to synthesize. Boranes are currently used for synthesizing important medications such as the cholesterol-lowering drug Lipitor, and the antidepressant Prozac.
Brown’s early years were marked by hardship. Born Herbert Brovarnik (Brown being an anglicised form of his original surname) on 22 May 1912 in London to Ukrainian immigrant parents, he was just a toddler when his family moved to Chicago in June 1914. His father, who ran a hardware store, passed away when he was 14. So, he had to drop out of school for a few years to run the store though he excelled in studies and had been allowed to skip several grades. After his mother took over the running of the family store, he was able to resume his school education and finally completed it in 1930.
To support the family, he did a few odd jobs for a while before starting his college education at Crane Junior College. But, no sooner he began his studies there than it was announced the institution was likely to close. So, he shifted to night school and funded his education by working part-time as a shoe clerk. Luckily for him, one of the instructors at Crane decided to let some students use his lab and complete their education on their own, and Brown happily accepted the offer. That’s when he met his future wife Sarah Baylen, the brightest chemistry student at the lab before he joined the group. The two of them and a few other students then moved to Wright Junior College. When they completed their course here in 1935, his girlfriend Sarah had scribbled a message in his yearbook, beginning with: To a future Nobel Laureate. Prophetic words that later on came true. That same year, Brown joined the University of Chicago from where he earned a B. S. degree in 1936, completing the two-year course in one year.
Interest in boron chemistry – a stroke of serendipity
As a graduation gift, Sarah, who had also joined the University of Chicago, gave Brown a copy of Alfred Stock’s book—The Hydrides of Boron and Silicon. Running short of cash, she had picked this book because at $2 it was the cheapest one in the University bookstore! However, it was this gift that peaked Brown’s interest in an obscure subject like the hydrides of boron. Deciding to choose it for his Ph.D. thesis, he studied with Professor H.I. Schlesinger who taught at the University of Chicago and was a well-known chemist actively engaged in this area of research.
The very next year, in 1937, Herbert married Sarah. He was then earning a meagre $400 a year as a graduate assistant from which he had to pay $300 for his tuition fees. But with Sarah obtaining a position at Billings Hospital in Medical Chemistry, they somehow managed to make ends meet. Brown got his Ph.D. in 1938, and being a married man now, tried in vain to find a job in the industry. Finally, he accepted the postdoctoral position offered by Professor M. S. Kharasch at a stipend of $1600, and that was how his academic career began. Out of necessity. When honoured with the Nobel Prize, he had famously said: “I am an unusual example of a chemist who ended up in academic work because he could not find an industrial position.”
One year later, Professor Schlesinger invited him to become his research assistant with the rank of instructor. This job gave him the opportunity to research methods of preparing lithium and sodium borohydrides and other related borohydrides, and studying their reactions. The compound sodium borohydride, NaBH4, that he and his Ph.D. and postdoctoral mentor Schlesinger discovered was used to generate hydrogen gas for weather balloons during World War II. It also has multiple applications today including the manufacture of different antibiotics, as a bleaching agent in the dyeing industry, and as a reducing agent in the synthesis of gold nanoparticles.
In 1947, Herbert Brown joined Purdue University in West Lafayette, Indiana, as professor of inorganic chemistry. In 1959, he was promoted to the position of R. B. Wetherill Professor and in 1960 to R. B, Wetherill Research Professor. When he retired in 1978, he acquired the status of R. B. Wetherill Research Professor Emeritus. He retained this position till his death in 2004.
The fortuitous gift of a cheap chemistry-related book motivated Brown to focus on boron for his Ph. D. research, and also led him to an area in chemistry for which he developed a lifelong attachment.
During the 1950s, he and his team of graduate students and post-doctoral researchers discovered that the simplest compound of boron and hydrogen, diborane, easily reacts with unsaturated organic molecules to produce organoboranes. He then carried out extensive research on organoboranes and on the reduction of different organic compounds with sodium borohydride, other related borohydrides, and aluminohydrides. His research work revolutionised many areas of chemistry, including synthetic organic chemistry, the compounds he discovered drastically reducing the time required for synthesising new compounds that could potentially be used as drugs, many of them directly leading to the successful manufacturing of important drugs such as hydrocortisone, steroids, and prostaglandins.
Brown mentored a large number of students and researchers. He would repeatedly urge his team members to refrain from spending more than eight hours a day in the laboratories. Instead, he stressed the value of sound thinking, planning, preparation, and execution of laboratory experiments, and timely interpretation of the results. The celebrated Japanese chemists Ei-ichi Negishi and Akira Suzuki, both 2010 Nobel Laureates in Chemistry, studied with Brown in the 1960s.
Herbert Brown held dozens of patents. During the course of his illustrious career spanning around seven decades, he published almost 1300 scientific publications, including a number of books, authoring on an average around 20 publications a year.
Brown’s many achievements were internationally acknowledged by way of a slew of awards. He was awarded the Nichols Medal for 1959, the ACS Award for Creative Research in Synthetic Organic Chemistry for 1960, the Linus Pauling Medal for 1968, the National Medal of Science for 1969, the Roger Adams Medal for 1971, the Charles Frederick Chandler Medal for 1973, the Madison Marshall Award for 1975, among others, and of course, the Nobel Prize for 1979.
He was elected to the National Academy of Sciences in 1957 and the American Academy of Arts and Sciences in 1966. He received an honorary Doctorate of Science degree from the University of Chicago in 1968, was an honorary member of the International Academy of Science, a member of the American National Academy of Sciences, honorary fellow of the Chemical Society (London), and a foreign member of the Indian National Academy of Sciences. He was inducted into the Alpha Chi Sigma Hall of Fame in 2000.
Besides, the Herbert C. Brown Laboratory of Chemistry at Purdue University has been named after him.
Herbert and Sarah generously provided a number of endowments – the ACS Herbert C. Brown Award for Creative Work in Synthetic Methodology, the Herbert C. Brown Lectures in 1983, the Herbert C. Brown Distinguished Professorship in 1998, and the Herbert C. Brown Center for Borane Research in 1998, to name a few.
Herbert Charles Brown died at the age of 92 on 19 December 2004 of a heart attack at a hospital in West Lafayette. Sarah died a few months later on 29 May 2005 at the age of 89. Interestingly, Brown’s distinguished one-time assistant Ei-ichi Negishi had visited him at his home barely 10 hours before he died to discuss an urgent chemistry-related matter. Negishi said, “For his age he appeared well, showing no sign of his sudden death the next morning.”
After Brown passed away, a biography issued by Purdue University lauded him for having discovered ‘a new continent in chemistry, a continent that will take many years of enthusiastic research effort to explore in detail and exploit for the good of mankind’.
His wife Sarah had sort of predicted decades earlier that he would someday be a Nobel Laureate. But, Brown not only achieved this distinction, he also rose to the stature of a trailblazing giant in the fields of organic and organoboron chemistry and came to be acknowledged as one of the foremost American chemists of the 20th century.
1. Nobelprize.org: Herbert C. Brown – Biographical – Nobel Media AB 2014, https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1979/brown-bio.html
2. Editors, Biography.com: Herbert C. Brown Biography – Biography.com, 2 April 2014, https://www.biography.com/people/herbert-c-brown-9228287
3. Mitch Jacoby: Herbert C. Brown Dead At Age 92 – Chemical & Engineering News, 21 December 2004, http://pubs.acs.org/cen/news/8251/8251brown12_23.html
4. Ei-Ichi Negishi: Herbert Charles Brown 1912 – 2004: A Biographical Memoir – National Academy of Sciences, 2008.
5. Purdue University, Department of Chemistry: Herbert C. Brown: 1979 Nobel Prize in Chemistry – https://www.chem.purdue.edu/hcbrown/
6. Editors, TheFamousPeople.com: Herbert C. Brown Biography – TheFamousPeople.com, 31 October 2017, https://www.thefamouspeople.com/profiles/herbert-c-brown-7571.php
7. Bea Perks: Obituary: Herbert C. Brown – Chemistry World, 1 February 2005, https://www.chemistryworld.com/news/obituary-herbert-c-brown/3003031.article.