Speaker: Dr. Chongxing Huang

Affiliation: The University of Hong Kong

Time: 16:00-17:30, March 3, 2025

Location: Lecture Hall, 2nd Floor, Building 6, Zhangjiang Campus

Host: Assoc. Prof. Guoqiang Yang

Abstract

Active methylene compounds are a class of readily accessible molecules that can be rapidly derivatized to construct complex architectures. In particular, disubstituted active methylene derivatives can undergo asymmetric transformations to efficiently generate highly valuable tetrasubstituted stereocenters. This talk will focus on a class of tetradentate ligands we developed, derived from prolinol or piperidine methanol frameworks. These ligand scaffolds can accommodate either two zinc centers or a single magnesium atom to catalyze the desymmetrization of malonates and 1,3-diketones.

Through desymmetric hydrosilylation of disubstituted malonates, we have achieved the stereoselective synthesis of various chiral building blocks with high enantiopurity, including all-carbon quaternary stereocenters, tertiary alkyl halides, α-tertiary amines, and tertiary alcohols. Based on these desymmetrized products, we have also designed novel and efficient synthetic routes to bioactive molecules and natural products. Furthermore, using the same ligand framework, we developed a magnesium-catalyzed desymmetric cyanosilylation of acyclic 1,3-diketones, affording vicinal tetrasubstituted carbons. The resulting chiral cyanohydrin products bearing multiple functional groups can be rapidly derivatized into more complex structures, particularly those containing contiguous stereocenters.

Brief introduction

Dr. Chongxing Huang received his B.S. degree from Peking University in 2012, where he worked under the guidance of Prof. Jianbo Wang and Prof. Yan Zhang. He then pursued his Ph.D. studies at The University of Texas at Austin and later at The University of Chicago with Prof. Guangbin Dong, earning his doctorate in 2017. From 2017 to 2019, he conducted postdoctoral research in the group of Prof. Barry M. Trost at Stanford University.

In 2019, Dr. Huang joined the Department of Chemistry at The University of Hong Kong as an Assistant Professor and Principal Investigator. His research focuses on asymmetric transformations of active methylene derivatives.