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A direct asymmetric alkynylation of ketones with new chiral CCN Rh catalysts containing N-heterocyclic carbene and oxazoline hybrid ligands is described. The catalytic reaction of fluoroalkyl-substituted ketones, ArCOCF2X (X=F, Cl, H), with aromatic and aliphatic alkynes yielded the corresponding chiral propargyl alcohols with high enantioselectivity. Control and kinetic experiments suggested a bis(alkynyl) Rh intermediate as the active species for the C−C bond-forming step. [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]

Functionalization of a β-C–H bond of a secondary aliphatic amine was accomplished using NCN pincer Rh complex 1 with a chiral bis(oxazolinyl)phenyl ligand. Complex 1 underwent asymmetric alkylation of dicyclopentylamine with CH 2 Cl 2 to form azametallacycle complex 2 . Additionally, the reaction of 1 with triethylamine in CH 2 Cl 2 resulted in the formation of ammonium ylide complex 3 via C–N bond formation. [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]

Transition-metal complexes with a chiral bis(oxazolinyl) phenyl (Phebox) ligand can construct suitable chiral environments around metal centers. Thus far, a number of transition-metal complexes in the range of early to late metals have been prepared via transmetalation, cyclometalation, and oxidative addition. The fundamental properties and catalytic activities of the resulting Phebox complexes have been extensively investigated. In particular, the Phebox-Rh and Phebox-Ru complexes were found to serve as efficient and selective catalysts in asymmetric reactions for carbon-carbon bond formation, reduction of unsaturated bonds, and functionalization reactions. In this Account, we summarize details of the Phebox complexes in terms of preparations, coordination chemistry, and catalytic applications. [ABSTRACT FROM AUTHOR]

Abstract: The catalytic reductive aldol coupling of 2-phenylpropionaldehyde and acrylate derivatives with rhodium-bisoxazolinyl catalysts resulted in high Felkin–Anh selectivity (β,γ-syn) up to 98% accompanied by α,β-anti diastereoselectivity and high enantiomeric excesses up to 99%. [Copyright &y& Elsevier]

Abstract: The oxidative addition reactions on 4,5-bis(2-oxazolinyl)-(2,7-di-tert-butyl-9,9-dimethyl)-9H-xanthene (Xabox)/rhodium(I) complex were examined using chloroacetate and substituted diynes to give stereoselectively the corresponding methoxycarbonylmethyl-rhodium(III) complex and rhodacyclopentadiene complexes, respectively. The rhodacycle complex 7 catalyzed the cyclotrimerization of the diynes and alkynes to give arene derivatives. [Copyright &y& Elsevier]

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]

Abstract: Chiral bis(oxazolinyl)phenyl–rhodium complexes act as catalysts in the combination of AgOTf for direct aldol reaction of ketones and aromatic aldehydes to give the corresponding β-hydroxyketones in high anti-selectivity and a good to high enantioselectivity up to 91% ee. [Copyright &y& Elsevier]

Abstract: Optically active dihydrocinnamate derivatives bearing the chiral carbon center at α-position were synthesized by Rh(Phebox)-catalyzed asymmetric reductive aldol coupling reaction with substituted cinnamates and benzaldehyde derivatives and subsequent dehydroxylation reaction. [Copyright &y& Elsevier]

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