37088-65-6Relevant academic research and scientific papers
Synthesis of chiral β-aminomalonates from 2-chlorotetrafluoroethanesulfinyl aldimines through the mannich reaction
Yang, Kai,Jiang, Min,Liu, Jin-Tao
, p. 3109 - 3115 (2015)
An efficient method for the synthesis of chiral β-aminomalonates in good yields and with high diastereoselectivities was achieved through Mannich reactions between 2-chlorotetrafluoroethanesulfinyl aldimines and dialkyl malonates in the presence of N-trim
Asymmetric synthesis of β-lactam via palladium-catalyzed enantioselective intramolecular c(sp3)-h amidation
Tong, Hua-Rong,Zheng, Wenrui,Lv, Xiaoyan,He, Gang,Liu, Peng,Chen, Gong
, p. 114 - 120 (2019/12/24)
β-Lactams are important scaffolds in drug design and frequently used as reactive intermediates in organic synthesis. Catalytic reactions featuring intramolecular C-H amidation of alkyl carboxamide substrates could provide a straightforward disconnection strategy for β-lactam synthesis. Herein, we report a streamlined method for asymmetric synthesis of β-aryl β-lactams from propanoic acid and aryl iodides via Pd-catalyzed sequential C(sp3)-H functionalization. The lactam-forming reaction provides an example of PdII-catalyzed enantioselective intramolecular C(sp3)-H amidation reaction and proceeds up to 94% ee. The use of a 2-methoxy-5-chlorophenyl iodide oxidant is critical to control the competing reductive elimination pathways of the PdIV intermediate to achieve the desired chemoselectivity. Mechanistic studies suggest that both steric and electronic effects of the unconventional aryl iodide oxidant are responsible for controlling the competing C-N versus C-C reductive elimination pathways of the PdIV intermediate.
HPLC enantioseparation on a homochiral MOF-silica composite as a novel chiral stationary phase
Tanaka, Koichi,Muraoka, Toshihide,Otubo, Yasuhiro,Takahashi, Hiroki,Ohnishi, Atsushi
, p. 21293 - 21301 (2016/03/08)
The last frontier in the development of chiral stationary phases for chromatographic enantioseparation involves homochiral metal-organic frameworks (MOFs). Using enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthalene-6,6′-dicarboxylic acid as a starting material, we prepared three homochiral MOFs that were further used as chiral stationary phases for high-performance liquid chromatography to separate the enantiomers of various kinds of racemic sulfoxides, sec-alcohols, β-lactams, benzoins, flavanones and epoxides. The experimental results showed excellent performances for enantioseparation, and highlighted that enantioseparation on homochiral MOF columns is practical.
Studies on N-activation for the lipase-catalyzed enantioselective preparation of β-amino esters from 4-phenylazetidin-2-one
Sundell, Riku,Kanerva, Liisa T.
, p. 1500 - 1506 (2015/03/04)
The effect of N-substitution was examined for the enantio-selective lipase-catalyzed ring-opening reaction of racemic 4-phenylazetidin-2-one with methanol in dry organic solvents. Marked differences in the reactivity of various N-protected 4-phenylazetidin-2-ones were observed. Preparativescale reactions with Candida antarctica lipase B (Novozym 435 preparation) yielded N-acylated methyl (R)-3-amino-3- phenylpropanoates with enantiomeric excess (ee) values >99% in up to a 49% isolated yield, whereas Thermomyces lanuginosus lipase (Lipozyme TM IM) gave enantiomerically enriched methyl (S)-3-acetamido-3-phenylpropanoate. Candida antarctica lipase A catalyzed the cleavage of the N-chloroacetyl protective group, whereas all of the other examined lipases underwent the ring-opening reaction.
Homochiral coordination polymers with nanotubular channels for enantioselective sorption of chiral guest molecules
Tanaka, Koichi,Kikumoto, Yuki,Hota, Naoki,Takahashi, Hiroki
supporting information, p. 880 - 883 (2014/03/21)
Two novel chiral coordination polymers were synthesized by treating C 2-symmetric 2,2′-dihydroxy- and 2,2′-dimethoxy-1, 1′-binaphthalene-3,3′-dicarboxylic acids with Cu2+, in which sorption of some chiral β-lactam compounds in the fr
METHOD FOR PRODUCING beta-AMINOCARBONYL COMPOUND
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, (2013/04/10)
An optically active β-aminocarbonyl compound is obtained by a Mannich reaction between an aldimine in which: nitrogen is protected and a malonic acid diester, in the presence of optically active BINOL and dialkyl magnesium (in which two alkyl groups are the same or different) in an amount 1 to 2 molar times the amount of the BINOL.
Kinetic resolution of β-lactams via enantioselective N-acylation
Yang, Xing,Bumbu, Valentina D.,Birman, Vladimir B.
experimental part, p. 4755 - 4757 (2011/11/04)
Enantioselective N-acylation of 4-aryl-β-lactams in the presence of acyl transfer catalyst Cl-PIQ provides an effective method for their non-enzymatic kinetic resolution.
Triclorosilane-mediated stereoselective synthesis of β-amino esters and their conversion to highly enantiomerically enriched β-lactams
Guizzetti, Stefania,Benaglia, Maurizio,Bonsignore, Martina,Raimondi, Laura
, p. 739 - 743 (2011/04/22)
A highly stereoselective trichlorosilane-mediated reduction of N-benzyl enamines was developed; the combination of a low cost, easy to make metal-free catalyst and an inexpensive chiral auxiliary allowed to perform the reaction on substrates with different structural features often with total control of the stereoselectivity. By easy deprotection through hydrogenolysis followed by conversion of β-aminoester to 2-azetidinones, the synthesis of enantiomerically pure β-lactams (>98% e.e.) was successfully accomplished.
Comparison of separation performances of amylose- and cellulose-based stationary phases in the high-performance liquid chromatographic enantioseparation of stereoisomers of β-lactams
Pataj, Zoltan,Ilisz, Istvan,Berkecz, Robert,Forro, Eniko,Fueloep, Ferenc,Peter, Antal
experimental part, p. 120 - 128 (2010/09/10)
High-performance liquid chromatographic methods were developed for the separation of the enantiomers of 19 β-lactams. The direct separations were performed on chiral stationary phases containing either amylose-tris-3,5- dimethylphenyl carbamate, (Kromasil
Magnesium(II)-binaphtholate as a practical chiral catalyst for the enantioselective direct mannich-type reaction with malonates
Hatano, Manabu,Horibe, Takahiro,Ishihara, Kazuaki
supporting information; experimental part, p. 3502 - 3505 (2010/09/11)
(Equation Presented). A highly enantioselective direct Mannich-type reaction of aldimines with dialkyl malonates was developed with the use of a Mg(II)-BINOLate salt, which was designed as a cooperative acid-base catalyst that can activate both aldimines and malonates. Optically active β-aminoesters and α-halo-β-aminoesters could be synthesized in high yields and with high enantioselectivities. This inexpensive and practical Mg(II)-BINOLate salt could be used in gram-scale catalysis.
