22436-30-2Relevant academic research and scientific papers
Sterically Hindered Chiral Ferrocenyl P,N,N-Ligands for Highly Diastereo-/Enantioselective Ir-Catalyzed Hydrogenation of α-Alkyl-β-ketoesters via Dynamic Kinetic Resolution
Hou, Chuan-Jin,Hu, Xiang-Ping
supporting information, p. 5592 - 5595 (2016/11/17)
A new class of sterically hindered chiral ferrocenyl P,N,N-ligands have been prepared through a two-step transformation from (Sc,Rp)-PPFNH2, in which a new (R)-stereogenic center at the pyridinylmethyl position was generated in high diastereoselectivity. With these newly developed P,N,N-ligands, Ir-catalyzed asymmetric hydrogenation of various α-alkyl-substituted β-aryl-β-ketoesters via dynamic kinetic resolution has been realized in high diastereo- and enantioselectivities for the first time, which led to a variety of optically active anti-β-hydroxyesters in up to 99% ee. The study indicated that the additional stereocenter at the pyridinylmethyl position of these ligands is crucial to realize this hydrogenation.
Efficient and Practical Arene Hydrogenation by Heterogeneous Catalysts under Mild Conditions
Maegawa, Tomohiro,Akashi, Akira,Yaguchi, Kiichiro,Iwasaki, Yohei,Shigetsura, Masahiro,Monguchi, Yasunari,Sajiki, Hironao
experimental part, p. 6953 - 6963 (2010/02/28)
An efficient and practical arene hydrogenation procedure based on the use of heterogeneous platinum group catalysts has been developed. Rh/C is the most effective catalyst for the hydrogenation of the aromatic ring, which can be conducted in iPrOH under neutral conditions and at ordinary to medium H 2 pressures (10 atm). A variety of arenes such as alkylbenzenes, benzoic acids, pyridines, furans, are hydrogenated to the corresponding cyclohexyl and heterocyclic compounds in good to excellet yields. The use of Ru/C, less expensive than Rh/C, affords an effective and practical method for the hydrogenation of arenes including phenols. Both catalysts can be reused several times after simple filtration without any significant loss of catalytic activity.
Hexafluoroisopropanol: A powerful solvent for the hydrogenation of functionalized aromatic compounds
Fache, Fabienne,Piva, Olivier
, p. 1294 - 1296 (2007/10/03)
Various substituted aromatic compounds have been reduced under H 2 using RuCl3. The fluorous solvent hexafluoroisopropanol turned out to be particularly efficient in the case of compounds difficult to reduce in organic solvents.
Efficient cyclization of ω-oxo-α,β-unsaturated esters using lithium thiolate-initiated Michael-aldol tandem reaction
Ono, Masashi,Nishimura, Katsumi,Nagaoka, Yasuo,Tomioka, Kiyoshi
, p. 6979 - 6982 (2007/10/03)
The reaction of ω-oxo-α,β-unsaturated esters with lithium thiolates afforded the Michael-aldol tandem cyclization products in good to perfect stereoselectivity depending on the nature of thiolates.
Use of 1,3-Oxazolidin-2-one Derivatives of 3-Borylpropenoic Acids as β-Hydroxy Acrylic Acid Equivalents in the Asymmetric Diels-Alder Reaction Catalyzed by a Chiral Titanium Reagent
Narasaka, Koichi,Yamamoto, Ichiro
, p. 5743 - 5754 (2007/10/02)
Catalytic asymmetric Diels-Alder reaction was developed by employing 3-(3-borylpropenoyl)-1,3-oxazolidin-2-one as a β-hydroxyacrylic acid equivalent.With a catalytic amount of the titanium reagent, 3-(3-borylpropenoyl)-1,3-oxazolidin-2-ones react smoothly
CONVERSION OF ISOXAZOLINES TO β-HYDROXY ESTERS. SYNTHESIS OF 2-DEOXY-D-RIBOSE
Caldilora, P.,Ciancaglione, M.,De Amici, M.,De Micheli, C.
, p. 4647 - 4650 (2007/10/02)
A simple and efficient preparation of β-hydroxy esters with a well-defined stereochemistry has been developed using 3-bromoisoxazolines as key-intermediates.A synthesis of 2-deoxy-D-ribose is also reported.
Phosphorylated Sugars. Part 23. Synthesis and Reactions of Phosphodiesters containing 2-Aminoethanol and a Polyfunctional Alcohol and their Behaviour during Acid- and Base-catalysed Hydrolysis
Trigalo, Francois,Szabo, Ladislas
, p. 1733 - 1744 (2007/10/02)
Phosphodiesters of 2-aminoethanol and of polyhydroxylated alcohols and sugars have been synthesised; their behaviour in M-HCl and in saturated (ca. 0.2 M) Ba(OH)2 solutions at 100 deg C have been examined.With the exception of 2-aminoethyl ethyl phosphate which, in acidic medium, yielded 2-aminoethylphosphate, free 2-aminoethanol and phosphorylated polyols or sugars were the main products formed.Because of simultaneously and/or sequentially occurring reactions the structures of the phosphorylated derivatives formed gave no unambiguous information regarding the structure of the initial phosphodiester.
