Search

A square-planar Co4 amide cluster, Co4{N(SiMe3)2}4 ( 2), and an octahedral Co6 hydride cluster, Co6H8(P iPr3)6 ( 4), were obtained from metathesis-type amide to hydride exchange reactions of a CoII amide complex with pinacolborane (HBpin) in the absence/presence of P iPr3. The crystal structure of 4 revealed face-capping hydrides on each triangular [Co3] face, while the formal CoII2CoI4 oxidation state of 4 indicated a reduction of the cobalt centers during the assembly process. Cluster 4 catalyzes the hydrosilylation of 2-cyclohexen-1-one favoring the conjugate reduction. Generation of the catalytically reactive Co cluster species was indicated by a trapping experiment with a chiral chelating agent. [ABSTRACT FROM AUTHOR]

The enantioselective desymmetrizing conjugate hydrosilylation of prochiral differently γ,γ-disubstituted cyclohexadienone derivatives 2 to furnish the corresponding cyclohexenones 4 with a remote chiral all-carbon quaternary center at the γ position is described. Chiral rhodium-bis(oxazolinyl)phenyl complexes 1 were effective catalysts for this transformation. This catalytic system was extended to the asymmetric transformation of spirocarbocyclic cyclohexadienones 5 to give the corresponding products 6 with high enantiomeric ratios. [ABSTRACT FROM AUTHOR]

Highly efficient and enantioselective hydrosilylation of aromatic alkenes catalyzed by the chiral rhodium acetate complexes with the bis(oxazolinyl)phenyl ligands has been reported that afforded chiral silane derivatives with up to 99% ee. [ABSTRACT FROM AUTHOR]

Zinc acetate proved to be an efficient catalyst for hydro�silylation of ketones and aldehydes in the combination with (EtO)2MeSiH, and a good to excellent asymmetric induction was observed in the presence of chiral N2S2 ligands. [ABSTRACT FROM AUTHOR]

Conjugate hydrosilylation of 3,3-diarylacrylate derivatives catalyzed by chiral rhodium-bis(oxazolinyl)phenyl complexes (1 mol %) at 60 °C for 2 h was investigated to prepare optically active 3,3-diarylpropanoate derivatives in high yields up to 99% yield and high enantioselectivities up to 99%. [ABSTRACT FROM AUTHOR]

An enantioselective conjugate hydrosilylation of prochiral γ,γ-disubstituted cyclohexadienones furnishes cyclohexenones with a chiral quaternary γ-carbon atom. [ABSTRACT FROM AUTHOR]

Regio- and enantioselective hydrosilylation of alkenes is achieved using triethoxysilane in the presence of a chiral Rh-complex catalyst. [ABSTRACT FROM AUTHOR]