Research - The Gong Group @USTC - 龚流柱课题组

Research

Our lab is interested in addressing new concepts in asymmetric catalysis: organocatalysis, transition metal catalysis, organo-metal combined catalysis, and their applications to the synthesis of natural products and biologically active molecules.

Organocatalysis

The development of new chiral organocatalysts and asymmetric multicomponent reactions is main focus of our research. We have designed chiral prolinamide-type catalysts, which are so far the most efficient organocatalysts for asymmetric direct aldol reactions, and proposed “enamine-double hydrogen-bonding” activation mode, which is quite generally applicable and inspirable for the design of a big family of amino amide catalysts. We have identified that chiral BINOL-based bisphosphoric acids show unique capacity to drive enantioselective 1,3-dipolar cycloaddition. Our great interest in the development of chiral Brønsted acid-catalyzed MCRs has led to highly enantioselective Biginelli-type reactions, 1,3-dipolar cycloadditions and other annulation reactions.

Selected examples

Transition metal catalysis

Catalytic enantioselective C-H functionalization and transformations of olefins have long been our research focuses in metal catalysis. We have designed chiral bimetallic oxovanadium catalysts, which have enabled highly enantioselective oxidative coupling of naphthol derivatives. Recently, we adopted chiral anions, such as chiral phosphates and anionic stereogenic-at-metal complexes, to the metal-mediated C(sp³)-H functionalization and asymmetric transformation of olefins. Notably, we have found that the 3,3’-disubstituted BINOL-based phosphoramidites are excellent chiral ligands for transition metal-catalyzed asymmetric allylic C-H functionalization reactions and proposed a “concerted proton and two-electron transfer” process via which the allylic C-H cleaving event may occur.

Selected examples

Organo-metal combined catalysis

The asymmetric organocatalysis combined with metal catalysis integrates the catalytic activity of metals and organocatalysts to allow the simultaneous or sequential occurrence of multiply bond-breaking and forming events in stereochemical control, and thereby enables asymmetric transformations that are unable to offer high levels of enantioselectivity by virtue of either of the individual chiral catalysts. In 2001, our group first described an asymmetric allylic alkylation of glycine imino esters with allyl acetate cooperatively catalyzed by palladium complexes and chiral ammonium salts. In this proof of concept, the oxidative addition of palladium complexes to allyl acetate generates π-allylic fragments, while the chiral ammonium salts are actually responsible for controlling the stereoselectivity by formation of chiral ion pairs with nucleophiles. Over the last decade, our group have discovered a variety of binary catalytic systems consisting of metals (including Au, Pd, Cu, Rh, Ni, etc.) and chiral organocatalysts (including chiral Brønsted acids, chiral Lewis bases and others) in either cooperative or relay catalysis manner, culminating in many unprecedented asymmetric transformations.(Liu-Zhu Gong, Asymmetric Organo-Metal Catalysis: Concepts, Principles, and Applications,(2022))

Selected examples