Preparation of Pyrrolidine-Based PDE4 Inhibitors via Enantioselective Conjugate Addition of α-Substituted Malonates to Aromatic Nitroalkenes
作者:Paul J. Nichols、John A. DeMattei、Bradley R. Barnett、Nicole A. LeFur、Tsung-Hsun Chuang、Anthony D. Piscopio、Kevin Koch
DOI:10.1021/ol060398p
日期:2006.3.1
[reaction: see text] The enantioselective conjugateaddition of alpha-substituted malonates to aromatic nitroalkenes generates a stereocenter at the carbon bearing the aromatic group and an adjacent prochiral center from the alpha-substituted malonate. Nitro reduction followed by diastereoselective cyclization provides pyrrolidinones with two contiguous stereocenters, one of which is quaternary. This
[EN] PHENETHYLAMIDE DERIVATIVES AND THEIR HETEROCYCLIC ANALOGUES<br/>[FR] DÉRIVÉS DE PHÉNÉTHYLAMIDE ET LEURS ANALOGUES HÉTÉROCYCLIQUES
申请人:ACTELION PHARMACEUTICALS LTD
公开号:WO2010044054A1
公开(公告)日:2010-04-22
The invention relates to novel phenethylamide derivatives and their heterocyclic analogues of formula (I), wherein A, B, R1, R2 and R3 are as described in the application, and to the use of such compounds, or of pharmaceutically acceptable salts of such compounds, as medicaments, especially as orexin receptor antagonists.
products 6 and/or 7 are observed if the nitronates, generated from the substrate 1a, are added to 85% aqueous H2SO4 but only the hydrolyzed carboxylic acids 9 are generated when the β-nitrostyrenes 2 are reacted with Grignard reagents and worked up under the same condition. The nitrile oxides 7 can undergo 1,3-dipolar cycloaddition with alkenes or alkynes to generate 2-isoxazolines or isoxazoles. A one-pot
β型硝基苯乙烯1或2与格氏或有机锂试剂反应在乙醚或THF溶液由1,4-加成中间nitronates以产生甲。当用稀盐酸处理A时,获得高产率的硝基烷3(和肟4)或5。当将中间体A缓慢加入到冰冷的浓氢卤酸中时,可以分离出羟甲酰卤6、8或一氧化氮7。如果从基材1a产生的硝酸盐观察到相同的产物6和/或7。将β-硝基苯乙烯2加入到85%的H 2 SO 4水溶液中,但是当β-硝基苯乙烯2与格氏试剂反应并在相同条件下进行后处理时,仅产生水解的羧酸9。腈氧化物7可与烯烃或炔烃进行1,3-偶极环加成反应以生成2-异恶唑啉或异恶唑。据报道,通过分子内一氧化氮-烯烃环加成反应可以一锅合成[n,3,0]双环(n = 3或4)化合物23-27。
Enantioselective Addition of Sodium Bisulfite to Nitroalkenes. A Convenient Approach to Chiral Sulfonic Acids
作者:Ehsan Sheikhi、Narjes Rezaei、Alvaro Castilla、Amparo Sanz‐Marco、Carlos Vila、M. Carmen Muñoz、José R. Pedro、Gonzalo Blay
DOI:10.1002/ejoc.202101064
日期:2021.10.7
A bifunctional thiourea catalyzes the enantioselectiveaddition of sodium bisulfite to nitroalkenes to give chiral β-nitrosulfonic acids with good yields and enantiomeric excesses. The sulfonic acids can be converted into the corresponding esters by treatment with trimethyl orthoacetate.
derivatives as organocatalysts in the Michael addition of enamine intermediates formed from aldehydes to nitroolefins has been demonstrated. The best results were obtained when the reaction was run in the presence of (2R,2′R)-N-iPr-bipiperidine. The products were formed via an enamine intermediate with high diastereo- and enantioselectivity with relatively short reaction times.