- Copper-catalyzed [18F]fluorination of (Mesityl)(aryl)iodonium salts
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A practical, rapid, and highly regioselective Cu-catalyzed radiofluorination of (mesityl)(aryl)iodonium salts is described. This protocol utilizes [18F]KF to access 18F-labeled electron-rich, -neutral, and -deficient aryl fluorides under a single set of mild conditions. This methodology is applied to the synthesis of protected versions of two important radiotracers: 4-[18F]fluorophenylalanine and 6-[ 18F]fluoroDOPA.
- Ichiishi, Naoko,Brooks, Allen F.,Topczewski, Joseph J.,Rodnick, Melissa E.,Sanford, Melanie S.,Scott, Peter J.H.
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p. 3224 - 3227
(2014/07/08)
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- Synthesis of novel N-protected hydrophobic phenylalanines and their application in potential antibacterials
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An efficient synthesis of two new N-acetyl-4′-arylphenylalanines is described together with their incorporation into a number of cationic peptoid antibacterial agents, one of which had an MIC of 7.8 μg/mL against Staphylococcus aureus. Crown Copyright
- Boyle, Timothy P.,Bremner, John B.,Coates, Jonathan A.,Deadman, John,Keller, Paul A.,Pyne, Stephen G.,Somphol, Kittiya
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experimental part
p. 1001 - 1009
(2009/09/06)
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- Sonogashira and "click" reactions for the N-terminal and side-chain functionalization of peptides with [Mn(CO)3(tpm)] +-based CO releasing molecules (tpm = tris(pyrazolyl)methane)
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A recently identified photoactivatable CO releasing molecule (CORM) based on [Mn(CO)3(tpm)]+ was conjugated to functionalized amino acids and model peptides using the Pd-catalyzed Sonogashira cross-coupling and the alkyne-azide 1,3-dipolar cycloaddition ("Click reaction"). Both were found to be fully compatible with all functional groups present. The CORM-peptide conjugates were isolated in reasonable yield and high purity, as indicated by IR spectroscopy, ESI mass spectrometry and RP-HPLC. The myoglobin assay was used to demonstrate that they have CO release properties identical those of the parent compound. This work thus opens the way for a targeted delivery of CORMs to cellular systems.
- Pfeiffer, Hendrik,Rojas, Alfonso,Niesel, Johanna,Schatzschneider, Ulrich
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supporting information; experimental part
p. 4292 - 4298
(2009/10/09)
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- Direct ortho iodination of β- and γ-aryl alkylamine derivatives
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Two in one! A trifluoroacetamide protecting group not only masks an amine functionality, but also mimics peptidyl directing effects as a controlling unit in an efficient ortho iodination of a variety of biologically relevant small molecules (see example). (Chemical Equation Presented).
- Barluenga, Jose,Alvarez-Gutierrez, Julia M.,Ballesteros, Alfredo,Gonzalez, Jose M.
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p. 1281 - 1283
(2008/03/27)
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- PEPTIDIC COMPOUNDS
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The present invention provides a compound of formula (I), (II), (III) and (IV) as defined herein and pharmaceutically acceptable derivatives thereof. The present invention further provides use of the compounds of the present invention in the treatment of bacterial infection and in the treatment of HIV infection. Also provided are pharmaceutical compositions comprising the compounds of the present invention.
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Page/Page column 171
(2008/06/13)
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- Novel type of rigid C-linked glycosylacetylene-phenylalanine building blocks for combinatorial synthesis of C-linked glycopeptides
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C-linked 3- and 4-(glycosylacetylene)-Fmoc-phenylalanines were synthesized as rigid building blocks for synthesis of libraries of neoglycopeptide templates. Perbenzylated 1,5-galactonolactone, 1,5- gluconolactone, and 1,5-mannonolactone were reacted with cerium TMS-acetylide and the products reduced to the C-glycosylacetylene-TMS derivatives. The gluco and galacto configurations yielded exclusively the β-C-glycoside, whereas the mannonolactone gave a mixture of α-C- and β-C-anomer. The products were subjected to acetolysis and TMS cleavage. The resulting peracetylated glycosylacetylenes were cross-coupled with the (R,S)-N(α)- acetyl-3- and 4-iodophenylalanine O-methyl esters by Pd(0) catalysis in piperidine to give the eight possible C-linked glycosyl amino acid building blocks 33-40 as diastereomeric pairs. These were O-deacetylated. As an example of further conversion into neoglycopeptide templates the N-acetyl group of the 4-linked galacto-diastereomeric pair 43 was hydrolyzed selectively by acylase 1 and separated from the (R)stereoisomer. The product was converted to 4-(β-C-galactosylacetylene)(N(α)-Fmoc-)-L-phenylalanine (52) by reaction with Fmoc-OSu. Acid hydrolysis of galactosyl acetylene phenyl alanine 43 at elevated temperature afforded the conversion of the acetylene to the 1'-oxo derivative which was also N(α)-Fmoc protected. The building blocks were used in the glycopeptide synthesis of three neoglycopeptide templates 54, 55, and 56 known to bind to murine MHC class II E(k) and to present the glycan for interaction with the T-cell receptor. This template has previously been employed to elicit a carbohydrate specific T- cell response.
- Lowary, Todd,Meldal, Morten,Helmboldt, Arnim,Vasella, Andrea,Bock, Klaus
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p. 9657 - 9668
(2007/10/03)
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- Iodination of Aryltrimethylsilanes: A Mild Approach to Iodophenylalanine
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Phenylalanine has been labeled with the radioactive isotopes of iodine by using harsh conditions or toxic mercury compounds.A mild method of incorporating iodine onto an aryl ring was developed that combines two methods that have been used separately for the production of aryl iodides: (1) the use of the Lewis acid to activate the elecrophile, I2, and (2) the use of a trimethylsilyl group to direct the introduction of iodine.Simple aryltrimethylsilanes and a phenylalanine-containing peptide were successfully iodinated by this method.
- Wilson, Stephen R.,Jacob, Linda A.
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p. 4833 - 4836
(2007/10/02)
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