Asymmetric Multicomponent Reactions Based on Trapping of Active Intermediates

Area of Science:

• Organic Chemistry
• Catalysis
• Asymmetric Synthesis

Background:

• Metal carbenes, generated from transition metal-catalyzed diazo compound decomposition, are reactive intermediates.
• These carbenes react with nucleophiles (alcohols, amines, heterocycles) to form transient ylide or zwitterionic intermediates.
• Trapping these intermediates with electrophiles offers a pathway for complex molecule synthesis.

Purpose of the Study:

• To develop novel multicomponent reactions (MCRs) based on trapping metal carbene-derived intermediates.
• To explore the scope of nucleophiles and electrophiles in these MCRs.
• To achieve high stereocontrol in the synthesis of chiral polyfunctional molecules.

Main Methods:

• Utilizing transition metal catalysis for diazo compound decomposition to generate metal carbenes.
• Employing various nucleophiles (alcohols, anilines, indoles, pyrroles, arenes) and electrophiles (imines, aldehydes, Michael acceptors).
• Implementing asymmetric catalysis strategies including transition metal/chiral Lewis acid, transition metal/Brønsted acid, and chiral transition-metal catalysis.

Main Results:

• Successful development of novel MCRs involving diazo compounds, nucleophiles, and electrophiles.
• Demonstrated efficient trapping of oxonium/ammonium ylides and zwitterionic intermediates.
• Achieved excellent stereocontrol and broad substrate scope in the synthesized products.
• Provided evidence for the existence of intermediates and stepwise reaction pathways.

Conclusions:

• Established novel asymmetric MCRs for constructing chiral polyfunctional molecules.
• Validated the trapping of ylide and zwitterionic intermediates under asymmetric catalysis.
• Highlighted the versatility and efficiency of the developed methodologies for complex molecule synthesis.