Junlong Li, College of Pharmacy, Chengdu University, PR China

Title：Remote Site-selective Arene C–H Functionalization Enabled by N-Heterocyclic Carbene Organocatalysis

Abstract: Catalytic site-selective functionalization of distal C–H bonds represents a formidable challenge in organic synthesis. Particularly, the precise functionalization of distal aromatic C(sp2)–H bonds remain largely unexplored. Here we present a highly para-selective acylation strategy to target ultra remote aryl C(sp2)–H bonds, eight chemical bonds away from an activated functionality, through radical N-heterocyclic carbene organocatalysis. This method is developed on the basis of a unique single-electron pathway involving the site-selective activation of aryl C–H bonds by a nitrogen-centered radical generated in situ. Importantly, this organocatalytic approach shows potential for the functionalization of drugs, amino acids and peptides, thus highlighting its importance for medicinal chemistry. Our investigation encompassed meticulous mechanistic studies, including control experiments and density functional theory calculations, to unravel the intricacies behind the observed site selectivity and shed light on the mechanism of radical N-heterocyclic carbene organocatalysis.

Scheme 1.N-radical-directed para-selective acylation of ultraremote arene C–H bonds.

Biography: 

Jun-Long Li is a distinguished professor serving as the Vice Dean of the College of Pharmacy at Chengdu University and Deputy Director of the Sichuan Institute of Industrial Drug Discovery. He earned his Ph.D. from Sichuan University in 2013 and was subsequently a German Humboldt Scholar (2013-2015).

His primary research focuses on asymmetric catalysis and the synthesis of chiral drugs. Professor Li is a recipient of numerous prestigious accolades, including the National Young Chang Jiang Scholar award, and high-level provincial talent titles such as the Sichuan Emei Plan and Sichuan Outstanding Young Scholar.

As a principal investigator, he has led three national research projects, including grants from the National Natural Science Foundation of China. His scientific contributions have been recognized with several awards, including the First Prize of Sichuan Science and Technology Progress Award and the international Thieme Chemistry Journals Award.

He has authored over 60 influential publications in leading international journals, including Nature Catalysis, Science Advances, Chemical Society Reviews, Journal of the American Chemical Society, and Angewandte Chemie International Edition.