Double Ligands Enabled Ruthenium Catalyzed ortho-C-H Arylation of Dialkyl Biarylphosphines: Straight and Economic Synthesis of Highly Steric and Electron-Rich Aryl-Substituted Buchwald-Type Phosphines

A double-ligands enabled ruthenium catalyzed C(sp(2))-H arylation of dialkyl phosphines is described, which provides a straight access to aryl-substituted dialkyl phosphine ligands. The combination of 1,3-diketone and amino acid ligands is essential for this transformation. An important six-membered cycloruthenium intermediate was successfully isolated and characterized by X-ray diffraction. Mechanistic studies showed that the 1,3-diketone promoted the process of oxidative addition of cycloruthenium intermediate. Some of modified CyJohnPhos ligands exhibited highly catalytic activity in palladium catalyzed C-N bond formation.

Automated summary

The combination of 1,3-diketone and amino acid ligands is essential for the ruthenium-catalyzed C(sp(2))-H arylation of dialkyl phosphines, providing a direct access to aryl-substituted dialkyl phosphine ligands. Mechanistic studies showed that the 1,3-diketone promoted the process of oxidative addition of a cycloruthenium intermediate, and some modified CyJohnPhos ligands exhibited highly catalytic activity in palladium catalyzed C-N bond formation.