منابع مشابه
Asymmetric Hydrogenation and Transfer Hydrogenation of Ketones
Optically active alcohols are important building blocks in the synthesis of fine chemicals, pharmaceuticals, agrochemicals, flavors and fragrances as well as functional materials (Arai & Ohkuma, 2011; Klingler, 2007). Furthermore, molecular hydrogen is without doubt the cleanest reducing agent, with complete atom efficiency. Therefore, the catalytic, asymmetric hydrogenation (AH) of prochiral k...
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We consider a number of unit root tests for micro panels where the number of individuals is typically large, but the number of time periods is often very small. As we discuss, the presence of a unit root is closely related to the identification of parameters of interest in this context. Calculations of asymptotic local power and Monte Carlo evidence indicate that two simple t-tests based on ord...
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A novel highly enantioselective two step access to a unit B precursor of cryptophycins in good yields from commercially available starting materials has been developed. The key step is an asymmetric hydrogenation using the commercially available [(COD)Rh-(R,R)-Et-DuPhos]BF(4) catalyst. The synthetic route provides the advantage of less synthetic steps, proceeds with high yields and enantioselec...
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A co-impregnation method was applied to the Ni/Zr-HMS/HZSM-5 catalyst (with various amounts of zirconium) during the hydrogenation of benzene. The physicochemical properties of the prepared nickel catalyst were characterized using X - ray diffraction, X - ray fluorescence, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, temperature-programmed desor...
متن کاملAsymmetric Hydrogenation
The asymmetric hydrogenation of prochiral unsaturated compounds, such as alkenes, ketones, and imines, is one of the most efficient and straightforward methods for the preparation of optically active compounds. This method uses dihydrogen and small amounts of chiral transition metal complexes and is now recognized as economical, operationally simple, and environmentally friendly. It is frequent...
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ژورنال
عنوان ژورنال: Analytical Chemistry
سال: 1979
ISSN: 0003-2700,1520-6882
DOI: 10.1021/ac50050a030