91129-16-7Relevant academic research and scientific papers
Synthesis of Chiral α,β-Unsaturated γ-Amino Esters via Pd-Catalyzed Asymmetric Allylic Amination
Xia, Chao,Shen, Jiefeng,Liu, Delong,Zhang, Wanbin
supporting information, p. 4251 - 4254 (2017/08/23)
A Pd-catalyzed asymmetric allylic amination of 4-substituted 2-acetoxybut-3-enoates with amines has been developed for the regiospecific synthesis of chiral α,β-unsaturated γ-amino esters. The desired chiral aminated products can be obtained in up to 98%
Deracemisation of aryl substituted α-hydroxy esters using Candida parapsilosis ATCC 7330: Effect of substrate structure and mechanism
Baskar,Pandian,Priya,Chadha, Anju
, p. 12296 - 12306 (2007/10/03)
Candida parapsilosis ATCC 7330 was found to be an efficient biocatalyst for the deracemisation of aryl α-hydroxy esters (65-85% yield and 90-99% ee). A variety of aryl and aryl substituted α-hydroxy esters were synthesized to reflect steric and electronic effects on biocatalytic deracemisation. The mechanism of this biocatalytic deracemisation was found to be stereoinversion.
Studies on the stereoselective selenolactonization, hydroxy and methoxy selenenylation of α- and β-hydroxy acids and esters. Synthesis of δ- and γ-lactones
Aprile, Carmela,Gruttadauria, Michelangelo,Amato, Maria E.,D'Anna, Francesca,Lo Meo, Paolo,Riela, Serena,Noto, Renato
, p. 2241 - 2251 (2007/10/03)
The diastereoselective synthesis of hydroxy substituted γ- and δ-lactones was accomplished following two approaches. A 5- or 6-endo cyclization promoted by electrophilic selenium reagents of α- or β-hydroxy acids and a 5- or 6-exo cyclization of hydroxy esters obtained through a diastereoselective hydroxy selenenylation reaction of α- or β-hydroxy esters. Moreover, the diastereoselective methoxy selenenylation of the above compounds was investigated showing a case in which the compound that was unreactive in the hydroxy selenenylation conditions gave, in the methoxy selenenylation conditions, the deprotected diol. The usefulness of the methoxy selenenylation procedure was proven by the preparation of a symmetric compound unsymmetrically functionalized. Yields and selectivities were found to depend on substituents (Ph or alkyl groups at the carbon atom that undergoes the nucleophilic attack), mode of cyclization, kinetic or thermodynamic control conditions. In the latter case, silica gel played an important role.
A Stereospecific Access to Allylic Systems Using Rhodium(II)-Vinyl Carbenoid Insertion into Si-H, O-H, and N-H Bonds
Bulugahapitiya, Priyadarshanie,Landais, Yannick,Parra-Rapado, Liliana,Planchenault, Denis,Weber, Valery
, p. 1630 - 1641 (2007/10/03)
Rhodium-catalyzed decomposition of α-vinyldiazoesters in the presence of silanes, alcohols, ethers, amines, and thiols have been shown to produce the corresponding α-silyl, α-hydroxy, α-alkoxy, α-amino, and α-thioalkoxy esters in generally good yield with a complete retention of the stereochemistry of the double bond of the diazo precursor. An extension of the process in homochiral series has also been devised using either a chiral auxiliary attached to the ester function or achiral α-vinyldiazoesters and Doyle's chiral catalyst Rh2(MEPY)4. In the former approach, pantolactone as chiral auxiliary gave diastereoselectivities of up to 70%, while the second approach produced the desired allylsilane with ee as high as 72%. On the other hand, Rh2(MEPY)4-catalyzed insertion into the O-H bond of water led to poor or no enantioselectivity in good agreement with recent literature reports.
NAD(P)H MODELS 20 CHEMOSELECTIVE METAL ION CATALYZED REDUCTION OF α-KETO-β,γ-UNSATURATED ESTERS BY 1,4-DIHYDROPYRIDINE DERIVATIVES
Meijer, Louis H. P.,Pandit, Upendra K.
, p. 467 - 472 (2007/10/02)
Ethyl 2-oxo-4-aryl-3-butene-1-oates (1a-c) are reduced by NAD(P)H models (1-n-propyl-1,4-dihydronicotinamide (4) and Hantzsch ester (5)), in presence of magnesium perchlorate.One equivalent of the reductant reduces the substrates selectively to the corresponding 2-oxo-4-arylbutanoates (6, 10a, b).An additional equivalent and higher temperature, converts ethyl 2-oxo-4-phenylbutanoate (6) to ethyl 2-hydroxy-4-phenylbutanoate (7).Reduction of ethyl 2-oxo-4-phenyl-3-buten-1-oate (1a) by Hantzsch ester in C2H5OD or by Hantzsch ester-4,4-d2 in C2H5OH, leads to direct transfer of the hydrogen or deuterium, respectively, without isotopic scrambling.These results have been interpreted to support the hydride transfer mechanism.
