Coupling of aryl halides with aryl boronic acids with P(C6H5)(2-C6H4Cl)2 as the supporting ligand

The chlorinated triarylphosphine P(C6H5)(2-C6H4Cl)(2) (1) has been used as a supporting ligand in the Suzuki-Miyaura coupling of aryl boronic acids with aryl halides. Aryl bromides without ortho substituents were successfully coupled at room temperature, while reactions involving sterically hindered aryl bromides required slight heating (70 degreesC). Electron-deficient aryl chlorides were also successfully coupled with heating (90 degreesC). Key reaction parameters such as order of addition, choice of mineral base, solvent volume, temperature, 1/Pd ratio, as well as electronic and steric variation of the aryl halide have been investigated and are reported.