108530-03-6Relevant articles and documents
Synthesis of Enantiomerically Enriched Drug Precursors by Lactobacillus paracasei BD87E6 as a Biocatalyst
?ksüz, Selda,?ahin, Engin,Dertli, Enes
, (2018)
Global sales of single enantiomeric drug products are growing at an alarming rate every year. A total of 7 bacterial strains were screened for their ability to reduce acetophenones to its corresponding alcohol. Among these strains Lactobacillus paracasei BD87E6 was found to be the most successful biocatalyst to reduce the ketones to the corresponding alcohols. The reaction conditions were systematically optimized for the reducing agent Lactobacillus paracasei BD87E6, which showed high enantioselectivity and conversion for the bioreduction. The preparative scale asymmetric reduction of 3-methoxyacetophenone (1h) by Lactobacillus paracasei BD87E6 gave (R)-1-(3-methoxyphenyl)ethanol (2h) with 92% yield and 99% enantiomeric excess. Compound 2h could be used for the synthesis of (S)-rivastigmine which has a great potential for the treatment of Alzheimer's disease. This study demonstrates that Lactobacillus paracasei BD87E6 can be used as a biocatalyst to obtain chiral carbinol with excellent yield and selectivity. The whole cell catalyzed the reductions of ketone substrates on the preparative scale, demonstrating that Lactobacillus paracasei BD87E6 would be a valuable biocatalyst for the preparation of chiral aromatic alcohols of pharmaceutical interest.
Synthesis of light-induced expandable photoresponsive polymeric nanoparticles for triggered release
Wang, Zhen,Wang, Peng,Tang, Xinjing
, p. 1273 - 1281 (2013)
High stability of drug-delivery nanocarriers during blood circulation is critical for effective drug delivery and low systematic toxicity, although destabilization of these nanocarriers is required for efficient release when they reach target sites. To develop efficient polymeric nanocarriers, we intended to synthesize and characterize a group of cross-linked, light-induced, expandable, polymeric nanoparticles through miniemulsion polymerization. These synthesized nanoparticles were stable in aqueous solutions, although light irradiation led to particle uncaging and further particle expansion up to 315-fold in volume. This resulted in the efficient release of the encapsulated contents in aqueous solutions and three cell lines (HeLa, RAW264.7, and MCF-7). Selective triggered release was also successfully achieved with spatial resolution in cell monolayers. In addition, curcumin encapsulation and photoregulation of its release were realized. Further cell viability of encapsulated curcumin was successfully achieved with light activation. Open the cage: A series of cross-linked photolabile polymeric nanoparticles are described. Light irradiation leads to the particle swelling 315-fold in volume and the efficient release of the encapsulated contents in both aqueous solutions and cells. Selective triggered release on a cell monolayer is achieved. Curcumin is efficiently encapsulated in particles and photoregulation of its release and cell viability is also successfully achieved. Copyright
Release of Terminal Alkynes via Tandem Photodeprotection and Decarboxylation of o -Nitrobenzyl Arylpropiolates in a Flow Microchannel Reactor
Tebikachew, Behabitu Ergette,B?rjesson, Karl,Kann, Nina,Moth-Poulsen, Kasper
, p. 1178 - 1185 (2018)
Photocleavable protecting groups (PPGs) offer a complementary protection paradigm compared to traditional protection groups. Herein, an o-nitrobenzyl (NB) PPG was employed to protect a variety of arylpropiolic acids. Upon a cascade of light-triggered photodeprotection in a microchannel reactor (residence times of 100-500 s), followed by Cu-catalyzed decarboxylation at 60 °C, the NB-protected arylpropiolic acid afforded a terminal alkyne. This terminal alkyne was further reacted in situ with an azide via click chemistry to yield a 1,2,3-triazole in a one-pot reaction. Furthermore, the effect of different substituents (methyl, vinyl, allyl, and phenyl) at the benzylic position on the rate of photodeprotection was studied. The quantum yields of photolysis for the benzylic-substituted esters were determined to be as high as 0.45 compared to the unsubstituted ester with a 0.08 quantum yield of photolysis.
Enantioselective Addition of Chiral Organotitanium Derivatives to Aldehydes
Olivero, Alan G.,Weidmann, Beat,Seebach, Dieter
, p. 2485 - 2488 (1981)
Alkoxy- and aryloxy-organotitanum compounds 2-4 derived from (S)-2-methyl-1-butanol, (R)-2-butanol, (-)-menthol, quinine, cinchonine, and (S)-1,1'-binaphthol are added to aromiatic aldehydes to give optically active alcohols 5-10 in enantioselectivities of up to 88percent e.e., with nucleophilic transfer of methyl, phenyl, and 1-naphthyl groups.The Tables 1-3 list the effects of varying the reagents, the substrates, and the reaction conditions of the new asymmetric synthesis.
Chemoselective Derivatization of Folded Synthetic Insulin Variants with Potassium Acyltrifluoroborates (KATs)
Boross, Gábor N.,Schauenburg, Dominik,Bode, Jeffrey W.
, (2019)
Synthetic folded insulin variants containing an ornithine-hydroxylamine residue are readily modified in aqueous buffers by amide-forming ligations with potassium acyltrifluoroborates (KATs). The synthetic insulin analogs were prepared by Fmoc-SPPS, α-keto
Highly efficient iridium catalyst for asymmetric transfer hydrogenation of aromatic ketones under base-free conditions
Dong, Zhen-Rong,Li, Yan-Yun,Chen, Jian-Shan,Li, Bao-Zhu,Xing, Yan,Gao, Jing-Xing
, p. 1043 - 1045 (2005)
(Chemical Equation Presented) Catalytic systems generated in situ from the chiral PNNP ligands with iridium or rhodium hydride complexes exhibited excellent catalytic activity and good enantioselectivity in the asymmetric transfer hydrogenation of aromati
General method for the synthesis of caged phosphopeptides: Tools for the exploration of signal transduction pathways
Rothman, Deborah M.,Vazquez, M. Eugenio,Vogel, Elizabeth M.,Imperiali, Barbara
, p. 2865 - 2868 (2002)
(figure presented) An interassembly approach for the synthesis of peptides containing 1-(2-nitrophenyl)ethyl-caged phosphoserine, -threonine, and -tyrosine has been developed. Photochemical uncaging of these peptides releases the 2-nitrophenylethyl protecting group to afford the corresponding phosphopeptide. The peptides described herein are based on phosphorylation sites of kinases involved in cell movement or cell cycle regulation and demonstrate the versatility of the method and compatibility with the synthesis of polypeptides, including a variety of encoded amino acids.
Aminotriazole Mn(I) Complexes as Effective Catalysts for Transfer Hydrogenation of Ketones
Martínez-Ferraté, Oriol,Werlé, Christophe,Franciò, Giancarlo,Leitner, Walter
, p. 4514 - 4518 (2018)
A catalytic system based on complexes comprising abundant and cheap manganese together with readily available aminotriazole ligands is reported. The new Mn(I) complexes are catalytically competent in transfer hydrogenation of ketones with 2-propanol as hydrogen source. The reaction proceeds under mild conditions at 80 °C for 20 h with 3 % of catalyst loading using either KOtBu or NaOH as base. Good to excellent yields were obtained for a wide substrate scope with broad functional group tolerance. The obtained results by varying the substitution pattern of the ligand are consistent with an out-sphere mechanism for the H-transfer.
Mechanochemical, Water-Assisted Asymmetric Transfer Hydrogenation of Ketones Using Ruthenium Catalyst
Kolcsár, Vanessza Judit,Sz?ll?si, Gy?rgy
, (2022/01/04)
Asymmetric catalytic reactions are among the most convenient and environmentally benign methods to obtain optically pure compounds. The aim of this study was to develop a green system for the asymmetric transfer hydrogenation of ketones, applying chiral Ru catalyst in aqueous media and mechanochemical energy transmission. Using a ball mill we have optimized the milling parameters in the transfer hydrogenation of acetophenone followed by reduction of various substituted derivatives. The scope of the method was extended to carbo- and heterocyclic ketones. The scale-up of the developed system was successful, the optically enriched alcohols could be obtained in high yields. The developed mechanochemical system provides TOFs up to 168 h?1. Our present study is the first in which mechanochemically activated enantioselective transfer hydrogenations were carried out, thus, may be a useful guide for the practical synthesis of optically pure chiral secondary alcohols.
Preparation method of o-nitrobenzaldehyde
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Paragraph 0055-0059; 0062-0064, (2021/12/07)
The invention relates to the technical field of organic synthesis, in particular to a preparation method of o-nitrobenzaldehyde. The invention provides a preparation method of o-nitrobenzaldehyde, which comprises the following steps: (A) carrying out oxidation reaction on o-nitroethylbenzene to obtain 1-(2-nitrophenyl)ethanol; (B) carrying out oxidation reaction on the 1-(2-nitrophenyl)ethanol to obtain o-nitroacetophenone; (C) carrying out oxidation reaction on the o-nitroacetophenone to obtain the o-nitrobenzaldehyde. According to the preparation method, cheap o-nitroethylbenzene is taken as a raw material, and o-nitrobenzaldehyde is obtained through three steps of oxidation reactions under different conditions. The method is reasonable in route, few in side reaction, high in yield, simple to operate, mild in reaction condition, low in equipment requirement and suitable for large-scale industrial production.
Synthesis and Evaluation of Non-Hydrolyzable Phospho-Lysine Peptide Mimics
Hauser, Anett,Poulou, Eleftheria,Müller, Fabian,Schmieder, Peter,Hackenberger, Christian P. R.
supporting information, p. 2326 - 2331 (2020/12/09)
The intrinsic lability of the phosphoramidate P?N bond in phosphorylated histidine (pHis), arginine (pHis) and lysine (pLys) residues is a significant challenge for the investigation of these post-translational modifications (PTMs), which gained attention rather recently. While stable mimics of pHis and pArg have contributed to study protein substrate interactions or to generate antibodies for enrichment as well as detection, no such analogue has been reported yet for pLys. This work reports the synthesis and evaluation of two pLys mimics, a phosphonate and a phosphate derivative, which can easily be incorporated into peptides using standard fluorenyl-methyloxycarbonyl- (Fmoc-)based solid-phase peptide synthesis (SPPS). In order to compare the biophysical properties of natural pLys with our synthetic mimics, the pKa values of pLys and analogues were determined in titration experiments applying nuclear magnetic resonance (NMR) spectroscopy in small model peptides. These results were used to compute electrostatic potential (ESP) surfaces obtained after molecular geometry optimization. These findings indicate the potential of the designed non-hydrolyzable, phosphonate-based mimic for pLys in various proteomic approaches.
