- Model Studies on Protease-Catalysed Peptide Synthesis Using 9-Fluorenylmethoxycarbonyl Protected Amino Acid Derivatives
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Fmoc-Phe-OMe, Fmoc-Ala-OMe and Fmoc-Gly-OH were coupled with H-Leu-NH2 under catalytic action of chymotrypsin, papain and thermolysin, respectively.The influence of different reaction media and several reaction parameters, such as reactants and enzyme con
- Kuhl, Peter,Saeuberlich, Simone,Jakubke, Hans-Dieter
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- One-pot conversion of benzyl carbamates into fluorenylmethyl carbamates
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A simple one-pot procedure smoothly converted N-benzyloxycarbonyl groups into N-fluorenylmethoxycarbonyl groups via hydrogenation with a poisoned catalyst in the presence of Fmoc-OSu. Functional groups such as t-butyl esters, t-butyl ethers, and N-Boc were stable under the reaction conditions. (C) 2000 Elsevier Science Ltd.
- Dzubeck,Schneider
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- Imidazotetrazines as Weighable Diazomethane Surrogates for Esterifications and Cyclopropanations
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Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for glioblastoma) for use as synthetic precursors of alkyl diazonium reagents. TMZ was employed to conduct esterifications and metal-catalyzed cyclopropanations, and results show that methyl ester formation from a wide variety of substrates is especially efficient and operationally simple. TMZ is a commercially available solid that is non-explosive and non-toxic, and should find broad utility as a replacement for diazomethane.
- Svec, Riley L.,Hergenrother, Paul J.
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supporting information
p. 1857 - 1862
(2019/12/27)
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- Determination of Chemical and Enantiomeric Purity of α-Amino Acids and their Methyl Esters as N-Fluorenylmethoxycarbonyl Derivatives Using Amylose-derived Chiral Stationary Phases
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Liquid chromatographic enantiomer separation and simultaneous determination of chemical and enantiomeric purity of α-amino acids and their methyl esters as N-fluorenylmethoxycarbonyl (FMOC) derivatives was performed on three covalently bonded type chiral stationary phases (CSPs) derived from amylose derivatives. The enantiomer separation of α-amino acid esters as N-FMOC derivatives was better than that of the corresponding acids, especially for CSP 1 and 2. Chemical impurities as the corresponding racemic acids present in several commercially available racemic amino acid methyl esters were observed to be 0.49–17.50%. Enantiomeric impurities of several commercially available L-amino acid methyl esters were found to be 0.03–0.58%, whereas chemical impurities as the corresponding racemic acids present in the same analytes were found to be 0.13–13.62%. This developed analytical method will be useful for the determination of chemical and enantiomeric purity of α-amino acids and/or esters as N-FMOC derivatives using amylose-derived CSPs.
- Islam, Md. Fokhrul,Adhikari, Suraj,Paik, Man-Jeong,Lee, Wonjae
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p. 332 - 338
(2019/04/13)
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- Aqueous MW eco-friendly protocol for amino group protection
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In this paper a new catalyst-free and on-water method for protection of amines and amino acids with di-tert-butyl dicarbonate, 9-fluorenylmethoxycarbonyl chloride, acetyl chloride and tosyl chloride is presented. The protection can be realized in a few minutes under microwave-assistance. The reaction proved to be chemoselective in presence of ambident nucleophiles and water solution of di-tert-butyl carboxylic acid or chloride acid are the only wastes produced.
- Nardi,Cano, N. Herrera,Costanzo,Oliverio,Sindona,Procopio
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p. 18751 - 18760
(2015/06/15)
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