- Highly enantioselective iridium-catalyzed hydrogenation of α,β-unsaturated esters
-
α,β-Unsaturated esters have been employed as substrates in iridium-catalyzed asymmetric hydrogenation. Full conversions and good to excellent enantioselectivities (up to 99 % ee) were obtained for a broad range of substrates with both aromatic- and aliphatic substituents on the prochiral carbon. The hydrogenated products are highly useful as building blocks in the synthesis of a variety of natural products and pharmaceuticals. Asymmetric hydrogenation: A variety of α,β-unsaturated esters were hydrogenated with high enantioselectivities (see scheme). The hydrogenated products have been used in synthetic transformations as well as in formal total syntheses. Copyright
- Li, Jia-Qi,Quan, Xu,Andersson, Pher G.
-
supporting information
p. 10609 - 10616
(2012/11/07)
-
- The first examples of selective carbonylation of n-butane and n-pentane
-
The polyhalomethane based superelectrophilic systems allowed us to accomplish the first efficient and selective carbonylation of n-butane and n- pentane with CO. Depending on the nature of the superelectrophilic system, Me3CCOOR or EtCH(Me)COOR (R = H, Alk) can be obtained at -20°C, 1 atm from n-butane and CO after water (α alcohol) treatment in = 90% yield based on the superelectrophilic system. Pentane reacts with CO in the presence d the CBr4 · 2AlBr3 superacid to give a single product, EtC(Me)2COOR, in almost quantitative yield.
- Akhrem, Irena,Orlinkov, Alexander,Afanas'eva, Lyudmila,Petrovskii, Pavel,Vitt, Sergei
-
p. 5897 - 5900
(2007/10/03)
-