81265-32-9Relevant academic research and scientific papers
Continuous method for preparing carbonate esters
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Page/Page column 13-14, (2021/06/09)
In one embodiment, a continuous process for preparing organic carbonate solvent of Formula (I) as described herein comprises contacting a first reactant (an alcohol) with a reactive carbonyl source (carbonyldiimidazole (CDI) or an alkylchloroformate) in the presence of a catalyst in reaction stream flowing through a continuous flow reactor at temperature 20° C. to about 160° C. and at a flow rate providing a residence time in the range of about 0.1 minute to about 24 hours; collecting a reactor effluent exiting from the continuous flow reactor; recovering a crude product from the reactor effluent; and distilling the crude product to obtain the organic carbonate compound of Formula (I). In another embodiment, the first reactant is an epoxide and the carbonyl source is carbon dioxide.
Three-Component Aminoarylation of Electron-Rich Alkenes by Merging Photoredox with Nickel Catalysis
Jiang, Heng,Yu, Xiaoye,Daniliuc, Constantin G.,Studer, Armido
supporting information, p. 14399 - 14404 (2021/05/26)
A three-component 1,2-aminoarylation of vinyl ethers, enamides, ene-carbamates and vinyl thioethers by synergistic photoredox and nickel catalysis is reported. 2,2,2-Trifluoroethoxy carbonyl protected α-amino-oxy acids are used as amidyl radical precursors. anti-Markovnikov addition of the amidyl radical to the alkene and Ni-mediated radical/transition metal cross over lead to the corresponding 1,2-aminoarylation product. The radical cascade, which can be conducted under practical and mild conditions, features high functional group tolerance and broad substrate scope. Stereoselective 1,2-aminoarylation is achieved using a L-(+)-lactic acid derived vinyl ether as the substrate, offering a novel route for the preparation of protected enantiopure α-arylated β-amino alcohols. In addition, 1,2-aminoacylation of vinyl ethers is achieved by using an acyl succinimide as the electrophile for the Ni-mediated radical coupling.
Practical Synthetic Procedures for the Iron-Catalyzed Intermolecular Olefin Aminohydroxylation Using Functionalized Hydroxylamines
Zhu, Cheng-Liang,Lu, Deng-Fu,Sears, Jeffrey D.,Jia, Zhen-Xin,Xu, Hao
, p. 3031 - 3041 (2016/09/09)
A set of practical synthetic procedures for the iron-catalyzed intermolecular olefin aminohydroxylation reactions in gram scale is reported. In these transformations, a bench-stable functionalized hydroxylamine is applied as the amination reagent. This method is compatible with a broad range of synthetically valuable olefins including those that are incompatible with the existing aminohydroxylation methods. It also provides valuable amino alcohol building blocks with regio- and stereochemical arrays that are complementary to known methods.
Iron(II)-catalyzed intermolecular amino-oxygenation of olefins through the N - O bond cleavage of functionalized hydroxylamines
Lu, Deng-Fu,Zhu, Cheng-Liang,Jia, Zhen-Xin,Xu, Hao
supporting information, p. 13186 - 13189 (2015/03/30)
An iron-catalyzed diastereoselective intermolecular olefin amino-oxygenation reaction is reported, which proceeds via an iron-nitrenoid generated by the N - O bond cleavage of a functionalized hydroxylamine. In this reaction, a bench-stable hydroxylamine derivative is used as the amination reagent and oxidant. This method tolerates a range of synthetically valuable substrates that have been all incompatible with existing amino-oxygenation methods. It can also provide amino alcohol derivatives with regio- and stereochemical arrays complementary to known amino-oxygenation methods.
A carbamate-based approach to primaquine prodrugs: Antimalarial activity, chemical stability and enzymatic activation
Mata, Graa,Do Rosário, Virgílio E.,Iley, Jim,Constantino, Luís,Moreira, Rui
experimental part, p. 886 - 892 (2012/03/22)
O-Alkyl and O-aryl carbamate derivatives of the antimalarial drug primaquine were synthesised as potential prodrugs that prevent oxidative deamination to the inactive metabolite carboxyprimaquine. Both O-alkyl and O-aryl carbamates undergo hydrolysis in alkaline and pH 7.4 phosphate buffers to the parent drug, with O-aryl carbamates being ca. 106-10 10 more reactive than their O-alkyl counterparts. In human plasma O-alkyl carbamates were stable, whereas in contrast their O-aryl counterparts rapidly released the corresponding phenol product, with primaquine being released only slowly over longer incubation periods. Activation of the O-aryl carbamates in human plasma appears to be catalysed by butyrylcholinesterase (BuChE), which leads to carbamoylation of the catalytic serine of the enzyme followed by subsequent slow enzyme reactivation and release of parent drug. Most of the O-aryl and O-alkyl carbamates are activated in rat liver homogenates with half-lives ranging from 9 to 15 h, while the 4-nitrophenyl carbamate was hydrolysed too rapidly to determine an accurate rate constant. Antimalarial activity was studied using a model consisting of Plasmodium berghei, Balb C mice and Anopheles stephensi mosquitoes. When compared to controls, ethyl and n-hexyl carbamates were able to significantly reduce the percentage of infected mosquitos as well as the mean number of oocysts per infected mosquito, thus indicating that O-alkyl carbamates of primaquine have the potential to be developed as transmission-blocking antimalarial agents.
