1522-41-4Relevant academic research and scientific papers
Acetyl Hypofluorite, a New Moderating Carrier of Elemental Fluorine and Its Use in Fluorination of 1,3-Dicarbonyl Derivatives
Lerman, Ori,Rozen, Shlomo
, p. 724 - 727 (1983)
Elemental fluorine and most of the fluoroxy reagents do not react efficiently or cleanly with 1,3-dicarbonyl derivatives or with their corresponding metal enolates even at -75 degC.It has been found that a suspension of sodium acetate in CFCl3 or in CFCl3-AcOH, when treated with elemental fluorine, forms a new electrophilic fluorinating reagent, CH3COOF (1), which reacts with substrates without further isolation or purification.This reagent is milder than F2, CF3OF, or CF3COOF and reacts successfully where the other reagents fail.When 1 reacts with 1,3-dicarbonyl compounds, the main product is the 1,3-dioxo-2-fluoro derivative in reasonable yields.When, however, the corresponding sodium enolates were treated with 1, the yields of the monofluoro derivatives were considerably higher.In the case of 1,3-dicarbonyl derivatives with low enol content, only the sodium enolates react with 1 to produce good to very good yields of the corresponding 2-monofluoro derivatives.Thus 1 can be considered as a moderating carrier of the highly reactive F2.
Synthesis of β-fluoro(dicarbonyl)ethylamines from 2-fluoro-ethylacetoacetate and dimethyl-2-fluoromalonate ester by batch and semi-continuous flow three-component Mannich reactions
Lisse, Etienne,Sandford, Graham
, p. 117 - 124 (2018)
Multi-component Mannich reactions between 2-fluoro-ethylacetoacetate or dimethyl-2-fluoromalonate ester, aldehyde and amine components allowing convenient synthesis of β-fluoro(dicarbonyl)ethylamine systems using both batch and continuous flow techniques are reported.
One-pot fluorination and organocatalytic Robinson annulation for asymmetric synthesis of mono- and difluorinated cyclohexenones
Huang, Xin,Zhao, Weizhao,Zhang, Xiaofeng,Liu, Miao,Vasconcelos, Stanley N.S.,Zhang, Wei
, (2018)
A one-pot fluorination and organocatalytic Robinson annulation sequence has been developed for asymmetric synthesis of 6-fluoroyclohex-2-en-1-ones and 4,6-difluorocyclohex-2-en-1-ones. The reactions promoted by cinchona alkaloid amine afforded products bearing two or three stereocenters in good to excellent yields with up to 99% ee and 20:1 dr.
Microreactors for elemental fluorine
Chambers, Richard D.,Spink, Robert C.H.
, p. 883 - 884 (1999)
A microreactor has been designed for use with elemental fluorine, both for selective fluorination and for perfluorination of organic compounds.
A Pd-Catalyzed [4 + 2] Annulation Approach to Fluorinated N-Heterocycles
García-Vázquez, Víctor,Hoteite, Larry,Lakeland, Christopher P.,Watson, David W.,Harrity, Joseph P. A.
supporting information, p. 2811 - 2815 (2021/05/05)
3-Fluoro- and trifluoromethylthio-piperidines represent important building blocks for discovery chemistry. We report a simple and efficient method to access analogs of these compounds that are armed with rich functionality allowing them to be chemoselectively derivatized with high diastereocontrol.
Preparation method 2 - fluoroethyl acetoacetate
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Paragraph 0013-0032, (2020/10/19)
The invention discloses a preparation method of ethyl 2-fluoroacetoacetate. The preparation method comprises the following steps: taking ethyl 2-chloroacetoacetate and excessive mixed gas containing fluorine gas as raw materials, taking hydrofluoric acid as a solvent and a catalyst, and adding a fluorine surfactant to react at low temperature, so as to prepare the ethyl 2-fluoroacetoacetate. According to the technical scheme, the ethyl 2-chloroacetoacetate and the excessive mixed gas containing the fluorine gas are used as the raw materials, so that a condition that the ethyl 2-chloroacetoacetate does not react completely so that the purity of a product is influenced is avoided; the hydrofluoric acid is added and is used as the solvent and the catalyst, so that on one hand, a reaction speed is improved; on the other hand, a condition that generated impurity gas is dissolved into a reaction mixed solution again can be avoided; the fluorine surfactant is added so that the ethyl 2-chloroacetoacetate, the hydrofluoric acid and the fluorine gas are more uniformly mixed and side reaction also can be inhibited. The ethyl 2-fluoroacetoacetate is prepared by adopting the technical scheme; the prepared product has high purity and the production cost is also reduced, so that the preparation method is suitable for large-scale production.
Recyclable Organocatalysts for a One-Pot Asymmetric Synthesis of 2-Fluorocyclohexanols Bearing Six Contiguous Stereocenters
Huang, Xin,Liu, Miao,Jasinski, Jerry P.,Peng, Bo,Zhang, Wei
, p. 1919 - 1926 (2017/06/09)
A recyclable fluorous bifunctional Cinchona alkaloid/thiourea-catalyzed quadruple fluorination/Michael/Michael/aldol sequence has been developed for the one-pot synthesis of cyclohexanols bearing six contiguous stereocenters including a fluorinated tertiary carbon. By using readily available starting materials including β-keto esters, β-nitrostyrenes, and α,β-unsaturated aldehydes, fully functionalized cyclohexanols were synthesized in 52–80% yields with up to 99% ee and >20:1 dr. The fluorous catalyst could be easily recovered by fluorous solid-phase extraction in 94–97% yield and >98% purity. In addition to the high synthetic efficiency achieved through the pot economic reactions, other green techniques such as transition metal-free catalysis and catalyst recovery are also employed. (Figure presented.).
A facile and mild approach for stereoselective synthesis of α-fluoro-α,β-unsaturated esters from α-fluoro-β-keto esters via deacylation
Qian, Jinlong,Yi, Wenbin,Lv, Meifang,Cai, Chun
supporting information, p. 127 - 132 (2015/02/02)
The highly stereoselective olefination reaction of α-fluoro-β-keto esters for the synthesis of α-fluoro-α,β-unsaturated esters has been developed. The olefination combines nucleophilic addition, intramolecular nucleophilic addition, and elimination in one step, as well as provides a facile synthetic approach to α-fluoro-α,β-unsaturated esters which are important units in many biologically active compounds and useful precursors in a variety of functional-group transformations.
One-pot fluorination and Mannich reactions of 1,3-dicarbonyl compounds
Pham, Kenny,Huang, Xin,Zhang, Wei
supporting information, p. 1998 - 2000 (2015/03/18)
Abstract One-pot fluorination of 1,3-dicarbonyl compounds with Selectfluor followed by the Mannich reaction with anilines and benzaldehydes is developed for the synthesis of α-fluoro and aminomethylated 1,3-dicarbonyl compounds.
Apparent electrophilic fluorination of 1,3-dicarbonyl compounds using nucleophilic fluoride mediated by PhI(OAc)2
Nash, Toby J.,Pattison, Graham
supporting information, p. 3779 - 3786 (2015/06/16)
The apparent electrophilic fluorination of 1,3-dicarbonyl compounds using Et3N·3HF as a nucleophilic fluoride source is reported. This reaction requires PhI(OAc)2 as oxidant and can be conducted safely in standard laboratory glassware. Alternative selectivity compared to Selectfluor was observed in some cases. This approach may reduce our reliance on difficult-to-handle fluorine gas and expensive electrophilic fluorinating agents derived from elemental fluorine. Mechanistic analysis related to the active fluorinating species and fluoride/acetate exchange is presented. The apparent electrophilic fluorination of 1,3-dicarbonyl compounds using Et3N·3HF mediated by the in-situ formation of PhIF2 from PhI(OAc)2 is reported. This can be performed safely in standard laboratory glassware, and this approach may reduce our reliance on difficult-to-handle fluorine gas and expensive electrophilic fluorinating agents derived from elemental fluorine.
