Friday, 27 June 2025 11:00am – 12:00pm

This seminar will be delivered in Chemistry Lecture Theatre 4

Speaker: Professor Jón Njardarson

Host: Dr Cassandra Fleming

Title: Asymmetric Anionic Amino Cope Adventures

Abstract
In this seminar, I will discuss how earlier investigations led us into the dormant exciting area of asymmetric anionic-amino Cope chemistry, which we have been enjoying exploring.  As part of these efforts, we have addressed how to streamline synthesis and push the limits of this reaction platform sterically and electronically, which has revealed several new reactions and promising application avenues that we are actively pursuing.  I will discuss how mechanistically different the anionic-amino Cope chemistry is from its anionic-oxy Cope variant and how we managed to navigate these differences to realize diastereoselective outcomes.  In challenging this new reaction platform on the steric frontier, we have discovered a new route to selectively make dienamide and trienamides, while on the electronic frontier we have diverted the reaction outcome with strategic fluorine and nitro group substitutions to establish new annulation routes to benzoates and chiral lactam products respectively.  Finally, I will share exciting unpublished results on how we have successfully leveraged this powerful new anionic cascade platform to form atropisomers selectively, whose success and selectivity is mechanism dependent as well as our approaches for rapidly construct complex pyridine, isoquinoline, pyrroline, pyrrole and dihydrofuran heterocyclic products.

Key References:

1. Am. Chem. Soc. 2017, 139, 13141
2. Am. Chem. Soc. 2021, 143, 5793
3. Org. Chem. 2021, 86, 10555
4. Org. Lett. 2022, 24, 7978   
5. Org. Lett. 2023, 25, 39
6. Org. Chem. 2023, 88, 17845

Bio
Jón was born and raised in the town of Akranes, Iceland. After receiving a BS in chemistry from the University of Iceland, Jón moved to Yale University where he joined the research group of Professor, John L. Wood and worked on the total synthesis of the natural products CP-225,917 CP-263,114 and new dearomatization reactions. Jón then moved to New York City to work in the laboratory of Professor Samuel J. Danishefsky at the Memorial Sloan-Kettering Cancer Center as a General Motors Cancer Research Scholar.  While in the Danishefsky group, Jón completed the total syntheses of epothilone 490 and migrastatin. Jón moved to Ithaca in 2004 to start his independent career at Cornell University, where he launched a research program focused on natural products and the development of new reactions. In 2010 Jón and his group moved west to Tucson where he is a professor in the Department of Chemistry and Biochemistry at the University of Arizona.   Jón’s group works on diverse organic synthesis topics such as new reaction development, total syntheses, drug discovery, novel material chemistry, chemical education and most recently machine learning. Jón is the creator of the popular Top 200 Drug poster series and the widely used app/website Chemistry By Design (CByD).