Search

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: 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: 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]