High activity in the palladium-catalyzed Suzuki-Miyaura reactions of aryl chlorides with arylboronic acids was furnished using biphenylene-substituted di- tert-butylruthenocenylphosphine (R-Phos) as a supporting ligand. Substrate combinations even for the construction of highly hindered tetra- ortho-substituted biaryls can be achieved in good to excellent yields with low catalyst loadings in short reaction times.

A highly general, active, and stable catalytic system was realized in the palladium-catalyzed Suzuki-Miyaura reactions of sterically hindered aryl bromides with arylboronic acids using biphenylene-substituted di-tert-butylruthenocenylphosphine (R-Phos) as a supporting ligand.

Polyphenyl derivatives Q 0700 Biphenylene-Substituted Ruthenocenylphosphine for Suzuki-Miyaura Coupling of Sterically Hindered Aryl Bromides. -(HOSHI*, T.; SAITOH, I.; NAKAZAWA, T.; SUZUKI, T.; SAKAI, J.-I.; HAGIWARA, H.; J. Org. Chem. 74 (2009) 10, 4013-4016; Fac. Eng., Niigata Univ., Ikarashi, Niigata 950-21, Japan; Eng.) -Jannicke 40-081

Polyphenyl derivatives Q 0700Biphenylene-Substituted Ruthenocenylphosphine for Suzuki-Miyaura Coupling of Aryl Chlorides. -The catalyst is designed for the coupling reaction of aryl chlorides with arylboronic acids. The reaction in the presence of K3PO4·H2O affords a variety of biaryls. For the preparation of tetra-ortho-substituted biaryls (VI) the change to the anhydrous K3PO4 and higher loading of the catalyst proves to be effective. -(HOSHI*, T.; NAKAZAWA, T.; SAITOH, I.; MORI, A.; SUZUKI, T.; SAKAI, J.-I.; HAGIWARA, H.; Org. Lett. 10 (2008) 10, 2063-2066; Fac. Eng., Niigata Univ., Ikarashi, Niigata 950-21, Japan; Eng.) -R. Steudel 41-090