122795-13-5Relevant articles and documents
Elemental fluorine, Part 23: Direct fluorination of β-ketoesters as an approach to enantioselective fluorination
Chambers, Richard D.,Nakano, Takashi,Okazoe, Takashi,Sandford, Graham
, p. 792 - 798 (2009)
Attempts to develop a direct enantioselective fluorination protocol using elemental fluorine and an appropriate Lewis acid and chiral ligand system are described.
Alkylation and decarboxylation of ethyl 2-fluoro-3-oxobutanoate as a route to functionalised α-fluoro-ketones
Hutchinson,Sandford, Graham,Vaughan, Julian F.S.
, p. 2867 - 2876 (1998)
Alkylation and decarboxylation of α-fluoro-β-ketoesters such as ethyl 2-fluoro-3-oxobutanoate offers a versatile route to a range of fluoro-ketoalkenes, demonstrating the synthetic utility of using α-fluoro-β-ketoesters as synthons for the preparation of synthetically more sophisticated selectively fluorinated systems.
Direct fluorination of 1,3-dicarbonyl compounds
Chambers, Richard D.,Greenhall, Martin P.,Hutchinson, John
, p. 1 - 8 (1996)
In acid media, 1,3-diketones and 1,3-keloesters can be fluorinated in high yield and often with high conversion mainly to the corresponding 2-fluoro- compounds. Diesters such as diethyl malonate do not react with fluorine under the same reaction conditions. The mechanism of these reactions has been investigated and while the identity of the electrophilic fluorinating species is uncertain, we believe that the essential features of the reaction pathway are understood. Copyright
NEW FLUORINATING REAGENTS - I. THE FIRST ENANTIOSELECTIVE FLUORINATION REACTION
Differding, Edmond,Lang, Robert W.
, p. 6087 - 6090 (1988)
Crystalline, optically pure N-fluoro sultams (-)-3 and (+)-5 are the first examples of enantioselective fluorinating reagents.Thus unprecedented enantiomeric excesses up to 70 percent are observed when various prochiral metal enolates are fluorinated by u
Chiral 1H NMR Analysis of Carbonyl Compounds Enabled by Cationic Cobalt Complex
Jang, Sumin,Kim, Hyunwoo
supporting information, (2020/06/04)
We report a newly prepared cationic cobalt(III) complex as a general and efficient chiral solvating agent that discriminates carbonyl compounds including esters, amides, ketones, and aldehydes. This cobalt(III) complex was further utilized to directly analyze both the conversion and the enantiomeric excess at once in the asymmetric fluorination.
Reagent-controlled enantioselectivity switch for the asymmetric fluorination of β-ketocarbonyls by chiral primary amine catalysis
You, Yang'en,Zhang, Long,Luo, Sanzhong
, p. 621 - 626 (2016/12/30)
A reagent-controlled enantioselectivity switch was uncovered in the asymmetric α-fluorination of β-ketocarbonyls by a chiral primary amine catalyst. By a simple swap of fluorination reagents, both enantiomers of the quaternary fluorination adducts could be obtained with good yields and high enantioselectivity. Mechanistic studies disclosed dual H-bonding and electrostatic stereocontrolling modes for the catalysis.
Enantioselective fluorination of β-ketoesters using tartrate derived bidentate bioxazoline-Cu(II) complexes
Balaraman, Kaluvu,Vasanthan, Ravichandran,Kesavan, Venkitasamy
, p. 919 - 924 (2013/09/23)
Enantioselective fluorination of aliphatic cyclic and acyclic β-ketoesters was achieved in excellent yield (up to 98%) with moderate to good enantioselectivities (up to 86% ee) using tartrate derived bidentate bioxazoline-Cu(II) complexes. This is the fir
Substrate range of the titanium TADDOLate catalyzed asymmetric fluorination of activated carbonyl compounds
Bertogg, Andreas,Hintermann, Lukas,Huber, Dominique P.,Perseghini, Mauro,Sanna, Maria,Togni, Antonio
experimental part, p. 353 - 403 (2012/05/07)
The substrate range of the [TiCl2(TADDOLate)] (TADDOL=α,α,α′,α′-tetraaryl-1,3-dioxolane-4, 5-dimethanol)-catalyzed asymmetric α-fluorination of activated β-carbonyl compounds has been investigated. Optimal conditions for catalysis are characterized by using 5 mol-% of TiCl2(naphthalen-1- yl)-TADDOLate) as catalyst in a saturated (0.14 mol/l) MeCN solution of F-TEDA (1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis- [tetrafluoroborate]) at room temperature. A series of α-methylated β-keto esters (3-oxobutanoates, 3-oxopentanoates) with bulky benzyl ester groups (60-90% ee) or phenyl ester (67-88% ee) have been fluorinated readily, whereas α-acyl lactones were also readily fluorinated, but gave lower inductions (13-46% ee). Double stereochemical differentiation in β-keto esters with chiral ester groups raised the stereoselectivity to a diastereomeric ratio (dr) of up to 96.5:3.5. For the first time, β-keto S-thioesters were asymmetrically fluorinated (62-91.5% ee) and chlorinated (83% ee). Lower inductions were observed in fluorinations of 1,3-diketones (up to 40% ee) and β-keto amides (up to 59% ee). General strategies for preparing activated β-carbonyl compounds as important model substrates for asymmetric catalytic α-functionalizations are presented (>60 examples). Copyright
Enantioselective α-fluorination and chlorination of β-ketoesters by cobalt catalyst
Kawatsura, Motoi,Hayashi, Shunsuke,Komatsu, Yuji,Hayase, Shuichi,Itoh, Toshiyuki
experimental part, p. 466 - 467 (2010/08/20)
We demonstrated the cobalt-catalyzed asymmetric a-fluorination and a-chlorination of β-ketoesters. Both reactions were achieved using a catalytic amount of Co(acac)2 with (R, R)Jacobsen's salen ligand; α-fluorinated or a-chlorinated products were thus obt
Enantioselective halogenation of β-oxo esters catalyzed by a chiral sulfoximine-copper complex
Frings, Marcus,Bolm, Carsten
supporting information; experimental part, p. 4085 - 4090 (2009/12/26)
A C1-symmetric amino sulfoximine has been used as a chiral ligand in copper-catalyzed asymmetric halogenation reactions of β-oxo esters. Both the catalyst itself and the reaction conditions were optimized, and 26 fluorinated, chlorinated, and b
