Events

Date: 22 October 2024   Time: 14:00 - 16:00

Location: GC601 Montagu LT

Catalyst NO bar for turning O/N-tethered alkynes: NO-heterocycles are impossible!

Santosh J. Gharpure

Department of Chemistry

Indian Institute of Technology Bombay, Powai, Mumbai – 400076

(Email: sjgharpure@chem.iitb.ac.in)

Abstract:

Metal catalysed transformations of alkynes have gained prominence for the synthesis of O-N/N-O heterocycles. However, their utility under metal free conditions is still under explored. In this context, we have demonstrated TMSOTf-mediated highly diastereoselective synthesis of isoxazolidine bearing three contiguous stereocentres via the alkyne-oximium cyclization. On the other hand, Lewis-acid-catalysed 5-endo-dig reductive hydroalkoxylation cascade on propargylic N-hydroxylamine gave expeditious, stereoselective access to isoxazolidine derivatives. Over the years, we have developed different strategies to get access of O-N/N-O heterocycles such as isoxazolidine, isoxazoline via hydroamination/1,3-sulfonyl migration, aminocyclization/1,3-sulfonyl migration and alkyne oximium cyclization (Figure 1). The talk will focus on some of the recent developments on using N/O-tethered alkynyl hydroxyl amines for the synthesis of O-N/N-O heterocycles from our laboratory.

Figure 1: Alkynes in the synthesis of O-N/N-O heterocycles

References and Notes:

Gharpure*, S. J.; Pal, J.; Pansuriya, K. C. Org. Lett. 2022, 24, 8769.
Gharpure*, S. J.; Raut, D. S.; Pal, J. Org. Lett. 2024, 26, 6497.
Gharpure*, S. J.; Vishwakarma, D. S.; Hajam, S. A. Org. Lett. 2023, 25, 2525.
Gharpure*, S. J.; Hajam, S. A.; Vishwakarma, D. S. Manuscript under Revision.

Bio-Sketch of Speaker

Prof. Santosh J. Gharpure

Professor In-Charge SINE &

Rasiklal Hemani Fragrance and Flavour Chair Professor

Department of Chemistry

Indian Institute of Technology Bombay

Powai, Mumbai - 400076, INDIA

Email: sjgharpure@chem.iitb.ac.in

Dr. Santosh J. Gharpure graduated with an M.Sc. degree in 1996, from Indian Institute of Technology Bombay, Powai. He obtained Ph.D. from Indian Institute of Science, Bangalore working with Late Prof. A. Srikrishna in 2001. He held a post-doctoral position with Prof. P. Andrew Evans at Indiana University, Bloomington, U.S.A. Subsequently, he joined the Department of Chemistry, IIT Madras, Chennai in the year 2004. In 2012, he moved to the Department of Chemistry, IIT Bombay, Powai, Mumbai as an Associate Professor and was promoted to Professor position in 2016. Currently, he holds the position of 'Rasiklal Hemani Fragrance and Flavour Chair Professor'. He is also Professor In-Charge of SINE, IIT Bombay's technology incubator. His research focuses on organic chemistry pertaining to natural and unnatural product synthesis and developing new synthetic methodologies. He is also working on problems relevant to industries from different domains.

Dr. Gharpure is a recipient of INSA Medal for Young Scientist. He was awarded IIT Madras Young Faculty Recognition Award (YFRA) for his contribution in teaching and research in 2010. He received B. M. Birla science Prize in Chemistry for the year 2011. He was selected as one of the Thieme Chemistry Journal Awardees for the year 2013. IIT Bombay conferred on him the Excellence in Teaching Award in the year 2015 and Departmental award for excellence in teaching in 2019. He was selected as Themis Medicare UICT Diamond Jubilee Distinguished Fellow in Pharmaceutical Science for the year 2015-16 of ICT, Mumbai. He was selected for the award of Chemical Research Society of India (CRSI) Bronze Medal in 2018. He is member of the International Advisory Board of European Journal of Organic Chemistry, Tetrahedron and Tetrahedron Letters. He is a Fellow of Royal Society of Chemistry (FRSC). He was awarded INSA Teachers Award 2021 by Indian National Science Academy, New Delhi.