22146-58-3Relevant academic research and scientific papers
Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Li, Jiacheng,Siang Tan, Suan,Kyne, Sara Helen,Wai Hong Chan, Philip
supporting information, p. 802 - 810 (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Preparation D at the same time-and L- uncle leucine method (by machine translation)
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, (2017/02/23)
This invention relates to a kind of simultaneously preparing D-and L- uncle leucine method, comprising the following steps: step (1): the positive butanol and 1,1-dichloroethylene reaction, to obtain 3,3-dimethyl butanoic acid product; step (2): in the 3,3-dimethyl-butyric acid, a catalyst is added in the product, at the same time access air and chlorine, to chloropivaloyl, to obtain 2-chloro -3,3-dimethyl butanoic acid; step (3): the obtained 2-chloro -3,3-dimethyl butanoic acid for aminolysis reaction, to obtain D-, L-tert-leucine; step (4): the D-, L-tert-leucine for acetylation and acetyl chloride, with L-heat-stable to amino acid acylase split and other processing, respectively obtained L-tert-leucine and D-tert-leucine; step (5): the split recovery acetylation or chloroactic acidylated recovery D-tert-leucine for racemic, is circulated and split. The present invention uses low-cost normal butanol and 1,1-dichloroethylene as the starting material. From economic benefits speaking, the cost of this invention is substantially below that of the biological reduction method. (by machine translation)
Efficient synthesis of N-acyl-α-amino acids via polymer incarcerated palladium-catalyzed amidocarbonylation
Akiyama, Ryo,Sagae, Takahiro,Sugiura, Masaharu,Kobayashi, Shu
, p. 3806 - 3809 (2007/10/03)
A novel polymer incarcerated Pd catalyst (PI Pd 7c) was synthesized from amide-containing polymer 6b, and this catalyst was shown to be effective in amidocarbonylation, which is a versatile one-pot method for the preparation of N-acyl-α-amino acids. The reactions proceeded smoothly with a wide variety of substrates, and no leaching of the Pd metal to the reaction mixture was detected.
Enzyme-assisted Preparation of D-tert.-Leucine
Laumen, Kurt,Ghisalba, Oreste,Auer, Kurt
, p. 1977 - 1980 (2007/10/03)
Optically pure D-tert.-leucine was obtained by the enzymatic hydrolysis of (±)-N-acetyl-tert. leucine chloroethyl ester after about 50% conversion, this being catalyzed by a protease from Bacillus licheniformis (Alcalase), and subsequent acidic saponification of the recovered ester. Among the methyl, ethyl, octyl, chloroethyl and trichloroethyl esters, the chloroethyl ester exhibited the highest rate of hydrolysis.
