Solvent-Free Ruthenium-Catalyzed Direct Coupling of Phosphines and Aryl Chlorides via C-H Activation: An Efficient and Straight Access to Aryl-Substituted Biarylphosphines

An efficient and straightforward synthesis of aryl-substituted biarylphosphines via unprotected amino acid-accelerated ruthenium-catalyzed P-directed ortho-C-H arylation reaction is described. This protocol utilized commercial and inexpensive (hetero)aryl chlorides as efficient arylating reagents under solvent-free reaction conditions. Notably, diverse aryl bromides were also effective for this transformation. With the protocol, a wide variety of mono-arylated biarylphosphines were obtained in moderate to high yields and excellent selectivity. Moreover, the aryl-substituted phosphine exhibited higher catalytic performance than its precursor and other substituted phosphines in palladium-catalyzed Suzuki coupling.

Automated summary

An efficient and straightforward synthesis of aryl-substituted biarylphosphines was developed using unprotected amino acids as accelerators in a ruthenium-catalyzed P-directed ortho-C-H arylation reaction. Commercial and inexpensive aryl chlorides were used as effective arylating reagents under solvent-free conditions, with diverse aryl bromides also proven to be effective. The resulting aryl-substituted phosphines exhibited higher catalytic performance in palladium-catalyzed Suzuki coupling compared to their precursors and other substituted phosphines.