Tertiary arsine ligands for the Stille coupling reaction

Area of Science:

• Organic Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• The Stille coupling reaction is a vital carbon-carbon bond-forming reaction in organic synthesis.
• Triphenylarsine is a known accelerator for Stille couplings, but the potential of other arsine ligands remains unexplored.

Purpose of the Study:

• To investigate the efficacy of various C3-symmetrical tertiary arsine ligands in the Stille coupling reaction.
• To identify superior arsine ligands for improved Stille coupling performance.

Main Methods:

• Synthesis of thirteen novel C3-symmetrical tertiary arsine ligands.
• Screening of these ligands in the Stille coupling reaction between tributylvinyltin and p-iodoanisole.
• Mechanistic investigation using dispersion-corrected density functional theory (DFT) calculations.

Main Results:

• Tri(p-anisyl)arsine was identified as the most effective ligand among the tested compounds.
• This ligand significantly accelerated the Stille coupling reaction rate.
• DFT calculations confirmed the energetic favorability of the reaction pathway mediated by tri(p-anisyl)arsine.

Conclusions:

• The study highlights the significant impact of ligand structure on Stille coupling efficiency.
• Tri(p-anisyl)arsine represents a promising new ligand for optimizing Stille coupling reactions.
• Further exploration of arsine ligands in cross-coupling reactions is warranted.