Mechanochemical Sequential Deoxygenative Cross-Coupling Reactions of Phenols Under Ruthenium-Nickel Catalysis

Area of Science:

• Organic Chemistry
• Catalysis
• Green Chemistry

Background:

• Traditional cross-coupling reactions often require harsh conditions and generate significant waste.
• Efficient methods for functionalizing phenols and constructing biaryl linkages are crucial in organic synthesis.

Purpose of the Study:

• To develop a novel mechanochemical strategy for the deoxygenative borylation of phenols.
• To enable subsequent Suzuki-Miyaura cross-coupling of phenols with aryl halides.
• To establish a more sustainable and efficient synthetic route compared to existing methods.

Main Methods:

• Ruthenium-catalyzed deoxygenative borylation of phenols using mechanochemistry.
• C-O bond cleavage of phenolic substrates.
• One-pot Suzuki-Miyaura cross-coupling of borylated phenols with aryl bromides.

Main Results:

• Successful implementation of the first mechanochemical strategy for Ru-catalyzed deoxygenative borylation of phenols.
• Demonstration of the extension to Suzuki-Miyaura-type cross-coupling of phenols with aryl bromides.
• High yields achieved for a wide range of phenolic substrates, producing aryl pinacolboranes and biphenyls.

Conclusions:

• The developed mechanochemical protocol offers a highly efficient and sustainable route for synthesizing aryl pinacolboranes and biphenyls.
• This method represents a significant advancement in green chemistry, emphasizing pot, atom, and step economy.
• The strategy provides a valuable alternative to classical cross-coupling reactions for phenol functionalization.