Modification of Chiral Monodentate Phosphine Ligands (MOP) for Palladium-Catalyzed Asymmetric Hydrosilylation of Cyclic 1,3-Dienes

Abstract

Several MOP ligands 5 containing aryl groups at 2′ position of (R)-2-(diphenylphosphino)-1,1′-binaphthyl skeleton were prepared and used for palladium-catalyzed asymmetric hydrosilylation of cyclic 1,3-dienes 6 with trichlorosilane. Highest enantioselectivity was observed in the reaction of 1,3-cyclopentadiene (6a) catalyzed by a palladium complex (0.25 mol %) coordinated with (R)-2-(diphenylphosphino)-2′-(3,5-dimethyl-4-methoxyphenyl)-1,1′-binaphthyl (5f), which gave (S)-3-(trichlorosilyl)cyclopentene of 90% ee.