Iron-Catalyzed gem-Specific Dimerization of Terminal Alkynes.

Area of Science:

• Organometallic Chemistry
• Catalysis
• Synthetic Organic Chemistry

Background:

• Terminal alkynes are versatile building blocks in organic synthesis.
• Developing efficient and selective catalytic systems for alkyne transformations remains a key challenge.
• Iron catalysis offers a sustainable and cost-effective alternative to precious metal catalysts.

Purpose of the Study:

• To report a novel iron(II) complex for catalyzing alkyne dimerization.
• To investigate the gem-specific homo- and cross-dimerization of terminal alkynes.
• To demonstrate the broad substrate scope and functional group tolerance of the catalytic system.

Main Methods:

• Synthesis and characterization of a well-defined iron(II) complex with Cp* and picolyl N-heterocyclic carbene ligands.
• Evaluation of the iron complex as a catalyst for terminal alkyne dimerization under various conditions.
• Assessment of catalyst compatibility with diverse functional groups, including amines (NH) and alcohols (OH).

Main Results:

• The iron(II) complex effectively catalyzes gem-specific homo- and cross-dimerization of terminal alkynes.
• The catalytic system operates without the need for additives.
• Broad substrate scope was demonstrated, including alkynes bearing polar functional groups.

Conclusions:

• A novel, well-defined iron(II) catalyst enables efficient and selective alkyne dimerization.
• The catalyst's ability to function without additives and tolerate functional groups expands its synthetic utility.
• This work provides a valuable new tool for constructing complex molecules from simple alkynes.