Over the last 50 years, the field of asymmetric catalysis in organic chemistry has been steadily gaining recognition. The 2001 Nobel Prize in Chemistry was awarded to K. Barry Sharpless, Ryoji Noyori and William S. Knowles for their pioneering work in this area.
A key contributor to this advancing field is Dr. Santanu Mukherjee, an Assistant Professor in the Organic Chemistry Department of Indian Institute of Science. Dr. Mukherjee studies chiral compounds ― molecules with same composition that appear as mirror images in their arrangement of atoms. His research focuses on developing new methods in hydrogen bonding catalysis to generate compounds that are structurally pure (only one of two possible mirror-image forms).
This field of research is relatively nascent in India, yet pertinent in today’s context since more than half of the drugs used in the world are chiral compounds. “The invention of new concepts, development of new catalysts and their application for the discovery of new chemical transformations are the main focus of contemporary research. In addition, the strategic implementation of well-established concepts for efficient and economic access to complex targets occupies a major area of our research,” explains Dr. Mukherjee.
Dr. Mukherjee was recently awarded the Prof. Priti Shankar Teaching Award for Assistant Professors for the year 2014, by the IISc Court.
He completed his bachelor’s degree in science and was a gold medallist from R. K. Mission Residential College, Narendrapur, India. His college education gave him the necessary foundation for research along with the values that he adheres to even today, he says. He then pursued a master’s degree in Chemistry from the prestigious Indian Institute of Technology, Kanpur, India where he was awarded the “General Proficiency Medal - 2002 for the Best Academic Performance in M.Sc. (2 Year)”
Despite his academic laurels, Dr. Mukherjee admits that he was never really his teachers' “blue-eyed boy.” “However, starting from my school days, I received a lot of support from many of my teachers and that continued all through my educational career,” he says. He initially wanted to be a veterinary doctor during high school, he jokingly admits, as he had heard that it was easier to get a job in that field. However, the unique challenges in the organic chemistry field, along with encouragement from his teachers motivated Dr. Mukherjee to pursue a career in it.
Dr. Mukherjee completed his PhD from the University of Cologne, Germany, and post-doctoral fellowships at Harvard University, Cambridge, USA and Max-Planck Institut für Kohlenforschung, Muelheim an der Ruhr, Germany. “I am particularly thankful to my postdoc mentors Professor Benjamin List and Professor E. J. Corey, who are giants in their respective research fields. I learned so much working with them, not only in chemistry but about many aspects of practicing this discipline,” he says. Dr. Mukherjee also won numerous other awards, such as the Thieme Chemistry Journals Award (2011), the National Academy of Sciences, India (NASI)-Young Scientist Platinum Jubilee Award (2013) and the Indian National Science Academy Medal for Young Scientists (2014).
Dr. Mukherjee has developed a number of protocols based on asymmetric Michael additions ― reactions that add nucleophiles (electron donors) called deconjugated butenolides to certain electrophilic (electron-accepting) unsaturated compounds. For example, he has developed a novel thiourea-based bifunctional catalyst derived from quinine for the addition of deconjugated butenolides to compounds called nitroolefins.
Dr. Mukherjee guides a young team of chemistry enthusiasts in his lab for research on dual catalysis with particular emphasis on merged/cooperative catalysis. The long-term objective of the group is to effectively combine different modes of catalysis for the invention of new transformations. Since most of the organic reactions can be visualized as the interaction between nucleophiles and electrophiles, suitable choice of reaction partners generated by employing either metal catalysts or organocatalysts has the potential to give rise to a wide range of unprecedented transformations. Such combined synthetic transformations would be more effective than the outcomes of either of these two catalysis modes acting independently.
Perhaps the most striking advantage of this type of merged catalysis is the number of ways in which the reactions could be rendered asymmetric i.e. tip the reaction in favour of generating a specific chiral molecule over its mirror image. Small chiral molecules as organocatalysts would be more versatile compared to conventional metal or small-molecule catalysis. “In my laboratory, we are currently working mostly on the development of new transformations with the help of organocatalysts. We are particularly interested in exploiting the power of hydrogen bonding and similar non-covalent interactions for activating relatively unreactive substrates. Our main objective is the synthesis of structurally and stereochemically complex products from easily accessible starting materials,” says Dr. Mukherjee.
Dr. Mukherjee feels privileged to be in a profession where he has the freedom to explore his curiosity and interests. “Freedom, of course, comes with responsibility, in my case towards my co-workers and towards the society in general. I dream of the day when our research will find application directly or indirectly for the betterment of the society,” he says.
He has written a number of articles related to his work and also has a patent in his name. He loves teaching and interacting with young students and hopes to be able to invest more time in guiding them in the years to come. Being both a researcher and a teacher is an ideal combination, he believes, as it gives him new perspectives and ideas which he can immediately test in the lab. To budding researchers, he advises, “Study to learn and not just to get marks in the exams. Marks will have temporary influence but the knowledge you acquire in the process will remain forever. Most importantly, love what you do and generate a passion for your work.”