Tandem reduction–olefination of triethyl 2-acyl-2-fluoro-2-phosphonoacetates and a synthetic approach to Cbz-Gly-Ψ[(Z)-CFC]-Gly dipeptide isostere
摘要:
(Z)-alpha-Fluoro-alpha,beta-unsaturated esters (Z)-7a-f were stereoselectively prepared by a tandem reduction-olefination of triethyl 2-acyl-2-fluoro-2-phosphonoacetates 6a-f with NaBH4 in EtOH. A concise synthesis of Cbz-Gly-Psi[(Z)-CF=C]-Gly (26) as a dipeptide isostere was achieved via the tandem reduction-olefination of the corresponding 2-acyl-2-fluoro-2-phosphonoacetate 20. (c) 2006 Elsevier Ltd. All rights reserved.
Stereoselective Synthesis of Fluoroalkenoates and Fluorinated Isoxazolidinones: N-Substituents Governing the Dual Reactivity of Nitrones
作者:G. K. Surya Prakash、Zhe Zhang、Fang Wang、Martin Rahm、Chuanfa Ni、Marc Iuliucci、Ralf Haiges、George A. Olah
DOI:10.1002/chem.201303509
日期:2014.1.13
α‐Fluoroalkenoates and 4‐fluoro‐5‐isoxazolidinones are of vast interest due to their potential biological applications. We now demonstrate the syntheses of (E)‐α‐fluoroalkenoates and 4‐fluoro‐5‐isoxazolidinones by the reactions between nitrones and α‐fluoro‐α‐bromoacetate. By altering N‐substituents in nitrones, (E)‐α‐fluoroalkenoates and 4‐fluoro‐5‐isoxazolidinones can be achieved, respectively, with
Exceptionally Mild, High-Yield Synthesis of α-Fluoro Acrylates
作者:Barbara Zajc、Shivani Kake
DOI:10.1021/ol0616236
日期:2006.9.1
chiral alkyl alpha-(1,3-benzothiazol-2-ylsulfonyl)-alpha-fluoroacetates can be readily synthesized by metalation-fluorination of (1,3-benzothiazol-2-ylsulfonyl)acetates. DBU-mediated condensations of these fluorinated synthons with aldehydes proceed in a facile manner at 0 degrees C or at room temperature giving high yields of alpha-fluoro acrylates. Ketones are unreactive under these conditions. The
Fused ring compounds, process for producing the same and use thereof
申请人:Takeda Chemical Industries, Ltd.
公开号:US06420375B1
公开(公告)日:2002-07-16
To provide a novel compound of the formula:
[wherein A1 ix a 5 or 6-membered ring which may be substituted by a group not containing a cyclic group, A2 is an aromatic ring which may be substituted, X is a divalent group, Y is a nitrogen atom or a methine group, Z is an ethenylene which may be substituted or ethynylene, R is a heterocyclic group which may be substituted, provided that 3,4-dihydro-6-[3-(1H-imidazol-1-yl)-1-propenyl]-2(1H)-quinolone and 2-[3-[5-ethyl-6-methyl-2-(benzyloxy)-3-pyridyl]-1-propenyl]benzoxazole are excluded.], or a salt thereof which has steroid C17,20-lyase inhibitory activity, and is useful for preventing and treating mammals suffering from, for example, primary cancer of malignant tumor, its metastasis and recurrence thereof.
A Convenient Method for the Synthesis of (<i>Z</i>)-α-Fluoroacrylates: Lewis Base-catalyzed Carbonyl Fluoroolefination Using Fluoro(trimethylsilyl)ketene Ethyl Trimethylsilyl Acetal
作者:Makoto Michida、Teruaki Mukaiyama
DOI:10.1246/cl.2008.890
日期:2008.8.5
A highly useful method is established for the stereoselective synthesis of (Z)-α-fluoroacrylates from various aldehydes and fluoro(trimethylsilyl)ketene ethyl trimethylsilyl acetal in the presence of a Lewis base catalyst. The ketene acetal, easily prepared from ethyl fluoroacetate, affords α-fluoroacrylates in high yields with excellent Z stereoselectivities under mild conditions.
建立了一种非常有用的方法,可在路易斯碱催化剂存在下,从各种醛和氟(三甲基硅基)乙酮三甲基硅基缩醛中立体选择性地合成 (Z)-α-氟丙烯酸酯。由氟乙酸乙酯轻松制备的乙烯酮缩醛可在温和的条件下以高产率和优异的 Z 立体选择性生成 α-氟丙烯酸酯。
Stereoselective Construction of Fluorinated Quaternary Stereogenic Centers via an Organocatalytic Asymmetric <i>exo</i>-Selective Diels–Alder Reaction in the Presence of Water
作者:Bojan P. Bondzić、Konstantinos Daskalakis、Tohru Taniguchi、Kenji Monde、Yujiro Hayashi
DOI:10.1021/acs.orglett.2c03043
日期:2022.10.14
A catalytic, asymmetric Diels–Alderreaction of α-fluoro α,β-unsaturated aldehydes and cyclopentadiene was developed using diarylprolinol silyl ether as an organocatalyst. The reaction proceeds in toluene with trifluoroacetic acid as an additive (condition A). Perchloric acid salt of diarylprolinol silyl ether also promotes the reaction using water as a reaction medium (condition B). In both cases