Events
Date 28 Aug 2024
Time 5:00 pm - 6:00 pm (HKT)
Venue Lecture Theatre P2, Chong Yuet Ming Physics Building
Speaker Prof. Zhongxing HUANG
Institution Department of Chemistry,
The University of Hong Kong
Self Photos / Files - Prof. Zhongxing HUANG poster
 
Title:
Desymmetrizing Active Methylene Derivatives
 
Schedule:
Date: 28th August, 2024 (Wednesday)
Time: 5 - 6 pm (HKT)
Venue: Lecture Theatre P2, Chong Yuet Ming Physics Building
Speaker:
Prof. Zhongxing HUANG
 
Department of Chemistry
The University of Hong Kong
 
Biography:
Zhongxing obtained his B.Sc. degree from Peking University in 2012 under the supervision of Professor Jianbo Wang and Yan Zhang. He conducted his graduate study in the laboratory of Professor Guangbin Dong at the University of Texas, Austin (2012-2016), and University of Chicago (2016-2017). His research in the Dong group focused on the development of a new palladium-catalyzed redox cascade for the direct β-functionalization of ketones. Upon the completion of his Ph.D. thesis, he joined the laboratory of Professor Barry M. Trost at Stanford University as a postdoctoral fellow and studied the cycloaddition reactions involving Pd-heteroallyl intermediates. In August 2019, Zhongxing joined the Department of Chemistry at the University of Hong Kong as an assistant professor. His current research interests focus on the asymmetric transformations of active methylene compounds.
 
Abstract:
Active methylene compounds represent a prominent family of structures that are easily available and can provide rapid access to complex molecules. When doubly substituted, these compounds can be rapidly converted to valuable tetra- and trisubstituted stereocenters via asymmetric transformations. Here, we report a prolinol- or pipecolinol-derived tetradentate ligand scaffold that can house two zinc centers or a single magnesium atom to desymmetrize malonic esters and 1,3-diketones. The reductive desymmetrization of disubstituted malonic ester via hydrosilylation has enabled the stereoselective synthesis of various enantioenriched building blocks, including quaternary stereocenters, tertiary alkyl halides, α-tertiary amines, and tertiary alcohols. Consequently, novel and expeditious approaches to bioactive natural metabolites, such as 2-dechlorohalomon, conagenin, and yezo’otogirins, were devised. Meanwhile, our efforts to spearhead the asymmetric decarboxylation will also be discussed. These investigations over the past two years have yielded novel chiral catalysts and catalysis paradigms that modulate the stereoselective proton transfer during the decarboxylation. As a result, racemic carboxylic acids easily accessed from active methylene compounds can be used to generate assorted chiral building blocks of interests to multiple fields.
 
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