Titanium Alkoxide-Based Regioselective Alkyne-Alkyne Reductive Coupling Mediated by In Situ Generated Arylamidate

Area of Science:

• Organic Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• Metal-mediated reductive coupling reactions are crucial for C-C bond formation.
• Developing selective and efficient coupling methods remains an active area of research.
• Directing group effects in metal catalysis offer pathways to control reactivity and selectivity.

Purpose of the Study:

• To describe a novel titanium alkoxide-catalyzed alkyne-alkyne reductive coupling reaction.
• To investigate the regioselectivity and scope of this transformation.
• To explore the potential directing influence of amide and carbamate functionalities.

Main Methods:

• Utilized titanium alkoxide precursors for catalytic system generation.
• Employed in situ generated arylamidate species as key intermediates.
• Performed reductive coupling of various alkyne substrates.

Main Results:

• Achieved exclusive formation of (E,E)-dienes across 37 examples.
• Demonstrated high regioselectivity in the reductive coupling process.
• Observed an apparent directing effect from amide and carbamate groups.

Conclusions:

• The developed method provides an efficient route to (E,E)-dienes via alkyne-alkyne reductive coupling.
• This work highlights the first reported instance of amide and carbamate directing effects in such metal-mediated couplings.
• The findings open new avenues for designing selective catalytic transformations.