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Abstract The influence factors of surfactant-type catalysts system on the asymmetric transfer hydrogenation (ATH) of ketones in water, including the length of aliphatic tail, the concentration of catalysts and the solvent, have been investigated. These factors played significant roles on reaction activity and stereo control. With single-chain surfactant-type catalyst Rh- L4 , α, β -unsaturated ketones especially the aliphatic derivatives affords excellent regioselectivities and enantioselectivities. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Described herein is a rhodium(III)-catalyzed coupling of aromatic ketazines or oximes with 2-vinyloxirane via directed C–H activation. This reaction proceeds efficiently under mild conditions with a low catalyst loading, especially in conditions with room temperature in the absence of additives for aromatic ketazines. A wide range of substituted substrates is supported and a possible mechanism is proposed according to the experimental results of kinetic isotopic effect, reversibility studies, and catalysis with rhodacycle intermediate c1 . [ABSTRACT FROM AUTHOR]

Described herein is an efficient new method for ortho -olefination of anilides in the presence of AgSbF 6 and NaOAc via rhodium(III)-catalyzed internal oxidative C–H bond activation based on hydroxyl as directing and oxidative group. A range of alkenes and functional groups on acetanilides is supported and a possible mechanism is proposed according to the experimental results. [ABSTRACT FROM AUTHOR]

Abstract: Chemoselective transfer hydrogenation of conjugated nitroalkenes catalyzed by [RhCl2Cp∗]2–diamine complex (Cp∗=η5-C5Me5) using HCOOH/Et3N (5:2) (TEAF) as a hydrogen source was realized. A variety of nitrostyrenes, β-methyl nitrostyrenes, and 3-methyl-4-nitro-5-alkenyl-isoxazoles were reduced smoothly in good to excellent yields in short reaction time. Other functional groups are inert under the reaction conditions. [Copyright &y& Elsevier]

Abstract: Efficient Rh-catalyzed asymmetric 1,4-addition of arylboronic acids to ethyl-γ-phthalimidocrotonate by using bis-sulfoxide ligand affords γ-aminobutyric acid (GABA) derivatives with high enantioselectivities (90–96% ee) under mild conditions. Optically pure (S)-Baclofen and (S)-Rolipram have been prepared successfully through this synthetic route. [ABSTRACT FROM AUTHOR]

Abstract: Asymmetric transfer hydrogenation of β,β-disubstituted nitroalkenes catalyzed by a chiral diamine–rhodium complex in combination with HCO2Na–HCO2H as a hydrogen source in water was successfully realized with high reactivity, excellent chemoselectivity and good enantioselectivity. The metal precursor and pH value of the aqueous solution have a large influence on the reactivity and chemoselectivity. The substituents on the benzene rings and the sulfonyl groups of TsDPEN have significant effects on the enantioselectivity. This catalytic asymmetric transformation is one of the most practical pathways to obtain optically active nitroalkanes. [ABSTRACT FROM AUTHOR]

Abstract: As an efficient catalyst for asymmetric transfer hydrogenation reaction (ATH reaction) of α,β-unsaturated ketones, Rh-Cp∗–TsDPEN (Cp∗ =1,2,3,4,5-pentamethylcyclopenta-1,3-diene, TsDPEN= N-(p-toluenesulfonyl)-1,2-diphenyl- ethylenediamine) shows high chemoselectivity on Ce:glyph name="dbnd" />C reduction. In our method, both Ce:glyph name="dbnd" />C bonds in a variety of chromenone derivatives were reduced efficiently in aqueous media, resulting in at least 98% ee and up to 99% yields in a convenient way without further purification. The product was a useful intermediate for deriving chiral chroman-4-amine, which was reported as an effective agent against hypotension and inflammatory pain by inhibiting human bradykinin B1 receptor. [Copyright &y& Elsevier]