Ligand-Modulated Cobalt-Catalyzed Alkene Carbocarbonylation Unlocks Aliphatic Ketone Synthesis

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Unsymmetric aliphatic ketones are crucial building blocks in organic molecules and bioactive compounds.
• Direct carbonylation of alkenes for ketone synthesis remains a significant challenge in organic chemistry.

Purpose of the Study:

• To develop a novel, efficient, and versatile method for the synthesis of unsymmetric aliphatic ketones.
• To explore the use of alkenes as feedstocks in a direct carbonylation strategy.

Main Methods:

• Cobalt-catalyzed four-component carbocarbonylation reaction.
• Utilized a newly developed bispyrazolylpyridine-type NNN-pincer ligand.
• Employed activated and unactivated alkenes, alkylzinc reagents, and alkyl halides under 1 atm of CO gas.

Main Results:

• Successfully synthesized a wide range of unsymmetric aliphatic ketones.
• Demonstrated excellent functional group compatibility, high regio- and chemoselectivity.
• Showcased the utility of CCl4, CF2Br2, and derivatives as electrophiles for modular synthesis.

Conclusions:

• The developed protocol provides a concise and divergent synthesis of structurally diverse aliphatic ketones.
• This methodology offers modular access to valuable compounds for synthetic and medicinal chemistry.
• The simple operation and high selectivity make this a practical approach for ketone synthesis.