Professor Varinder Aggarwal
Gassman Lecture #1
Professor Varinder Aggarwal
School of Chemistry
University of Bristol, UK
Host: Professor Courtney Roberts
Assembly Line Synthesis
Nature has evolved highly sophisticated machinery for organic synthesis, many of which resemble molecular assembly-line processes. So far chemists have been able to apply this type of approach in the synthesis of peptides and oligonucleotides but in these reactions, simple amide (C‒N) or phosphate (P‒O) bonds are created. It is much more difficult to make C‒C bonds but this is central to the discipline of organic synthesis. This difficulty is why organic synthesis is challenging and why robust, iterative or automated methodologies have not yet emerged.
Here, we describe the application of iterative homologation of boronic esters using chiral lithiated carbamates and chloromethyllithium enabling us to grow carbon chains with control over both relative and absolute stereochemistry. Applications of this strategy to the synthesis of natural products will be demonstrated. In addition, the methodology is used to answer fundamental questions about nature and the specific role of methyl substituents in carbon chains. By understanding their role, I will show that molecules can be created with linear or helical conformations or hybrids of the two.
Selected papers:
K. Yeung, R. C. Mykura, V. K. Aggarwal, Nat Synth, 2022, 1, 117–126.
J. L. Stymiest, G. Dutheuil, A. Mahmood, V. K. Aggarwal, Angew. Chem. Int. Ed., 2007, 46, 7491.
J. L. Stymiest, V. Bagutski, R. M. French, V. K. Aggarwal, Nature, 2008, 456, 778.
S. Balieu, G. E. Hallett, M. Burns, T. Bootwicha, J. Studley, V. K. Aggarwal, J. Am. Chem. Soc., 2015, 137, 4398.
M. Burns, S. Essafi, J. R. Bame, S. P. Bull, M. P. Webster, S. Balieu, J. W. Dale, C. P. Butts, J. N. Harvey, V. K. Aggarwal, Nature, 2014, 513, 183.
J. Wu, P. Lorenzo, S. Zhong, M. Ali, C. P. Butts, E. L. Myers, V. K. Aggarwal, Nature, 2017, 547, 436.
C. Sandford, V. K. Aggarwal, Chem. Commun., 2017, 53, 5481.
K. Yeung, R. C. Mykura, V. K. Aggarwal, Nat Synth, 2022, 1, 117–126.
Varinder Aggarwal
Varinder K. Aggarwal studied chemistry at Cambridge University and received his Ph.D. in 1986 under the guidance of Dr. Stuart Warren. After postdoctoral studies (1986-1988) under Prof. Gilbert Stork, Columbia University, he returned to the UK as a Lecturer at Bath University. In 1991 he moved to Sheffield University, where he was promoted to Professor in in 1997. In 2000 he moved to Bristol University where he holds the Chair in Synthetic Chemistry. He was elected Fellow of the Royal Society in 2012. Professor Aggarwal is a renowned organic chemist who has developed new chemical methods to assemble complex, biologically important molecules. His research includes new ways of speeding up, or catalysing chemical reactions, developing new classes of reagents for iterative synthesis, and applications of these methods in medicine, such as helping to provide more effective routes to potential vaccines against tuberculosis.
Gassman Lectureship in Chemistry
Regents Professor Paul G. Gassman died in April 1993, at the age of 57. He was internationally know in the chemical community, and left behind a legacy of achievement. During his career, he served as mentor and adviser to 85 doctoral and master’s candidates as well as dozens of postdoctoral associates and undergraduate students. Numerous awards, honors, and honorary degrees were bestowed in recognition of his contributions to research and his service to the scientific, professional, and university communities. Some of these awards include election to the National Academy of Sciences (1989) and to the American Academy of Arts and Sciences (1992); the James Flack Norris Award in Physical Organic Chemistry (1985); Arthur C. Cope Scholar Award (1986); and the National Catalyst Award of the Chemical Manufacturers Association (1990). He served as president of the American Chemical Society in 1990. He was co-chair of the organizing committees of the National Organic Symposium (1991) and the National Conferences on Undergraduate Research meeting (1992), on the University of Minnesota campus. It was his wish that a lectureship be established to bring distinguished organic chemists to the Department of Chemistry. We are proud to present this lecture series in his honor.