Computational Insight into Cu-Catalyzed C_sp-S Coupling to Form a Macrocyclic Alkynyl Sulfide.

Area of Science:

• Organic Chemistry
• Catalysis
• Computational Chemistry

Background:

• Copper-catalyzed C-S cross-coupling reactions are important for synthesizing sulfur-containing organic molecules.
• The formation of macrocyclic alkynyl sulfides via this method is particularly rare and challenging.

Purpose of the Study:

• To elucidate the mechanism of copper-catalyzed C-S cross-coupling for the formation of macrocyclic alkynyl sulfides.
• To provide a deeper understanding of the key intermediates and transformations involved in this synthetic pathway.

Main Methods:

• The study employed computational chemistry methods to investigate the reaction pathway.
• Analysis focused on the formation of copper-sulfur (Cu-S) species and subsequent reaction steps.

Main Results:

• Computational studies suggest a detailed mechanism for the formation of macrocyclic alkynyl sulfides.
• The proposed pathway involves the initial formation of Cu-S species.
• Subsequent alpha-addition/elimination at the ethynylic carbon was identified as the key step leading to macrocycle formation.

Conclusions:

• The findings provide valuable mechanistic insights into a rare copper-catalyzed reaction.
• Understanding this pathway can aid in the design and optimization of synthetic strategies for macrocyclic alkynyl sulfides.