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Trimethylsilyl Esters (trimethylsilyl + ester)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Carbon-14 radiosynthesis of combretastatin A-1 (CA1) and its corresponding phosphate prodrug (CA1P)

JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 14 2009
Rodney T. Brown
Abstract The natural product combretastatin A-1 (CA1) is isolated from the African bush willow tree, a member of the Combretaceae family. CA1 has important medicinal value, due in part to its ability to inhibit tubulin assembly. The prodrug combretastatin A-1 diphosphate (CA1P; OXi4503) is currently in human Phase I clinical trials as a vascular disrupting agent. This paper describes the carbon-14 radiosynthesis of [4,- 14C]CA1 and the corresponding phosphate prodrug salt [4,- 14C]CA1P in high specific activity (55,mCi/mmol). The carbon-14 label was introduced by methylation of the C-4, protected phenolic moiety of the CA1 precursor following removal of the tert -butyldimethylsilyl protecting group in the presence of [14C]methyl iodide. This was accomplished in excellent yield without significant Z to E isomerization. The [14C]-precursor ((Z)-1-[3,,[4,- 14C],5,-trimethoxyphenyl]-2-[2,,3,-di-[(isopropyl)oxy]-4,-methoxyphenyl] ethene) was subjected to a de- isopropylation reaction with TiCl4. The tetrabenzyl phosphate derivative of the resulting diol was prepared using fresh dibenzyl phosphite. Debenzylation with trimethylsilylbromide, followed by hydrolysis of the trimethylsilyl ester and adjustment of the pH with dilute aqueous hydrochloric acid yielded [4,- 14C]CA1P with an overall radiochemical yield of 8.4%. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Synthesis of new organophosphorus-substituted mono- and bis(trimethylsilyl)amines with PCH2N fragments and their derivatives

HETEROATOM CHEMISTRY, Issue 2 2010
Andrey A. Prishchenko
Convenient procedures for the synthesis of new organophosphorus-substituted mono- and bis(trimethylsilyl)amines with PCH2N moiety are proposed, starting from trimethylsilyl esters of organophosphorus acids, as well as 1,3,5-trialkylhexahydro-1,3,5-triazines and N -alkoxymethyl bis(trimethylsilyl)amines as aminomethylating reagents. Certain properties of the resulting compounds are presented. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:71,77, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20580 [source]

Synthesis of functionalized 2-trimethylsiloxy-substituted O -trimethylsilyl alkylphosphonites, their analogues, and derivatives

HETEROATOM CHEMISTRY, Issue 5 2008
Andrey A. Prishchenko
Nucleophilic addition of trimethylsilyl esters of tricoordinate organophosphorus acids to several functionalized alkylene oxides is proposed as convenient methods for the synthesis of new 2-trimethylsiloxysubstituted alkylphosphonites, their analogues, and derivatives. Also the new functionalized derivatives of these phosphonites, including amino, carboxy, or sulfo groups as well as certain properties of these compounds, which may be the important precursors of new functionalized 2-hydroxyalkylorganophosphorus acids, are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:450,454, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20453 [source]

Synthesis of functionalized 1-trimethylsiloxy-substituted O -trimethylsilyl alkylphosphonites and their derivatives

HETEROATOM CHEMISTRY, Issue 4 2008
Andrey A. Prishchenko
Nucleophilic addition of trimethylsilyl esters of tricoordinate organophosphorus acids to various functionalized aldehydes with vinyl, aryl, and heterocyclic fragments is proposed as a convenient method for the synthesis of new 1-trimethylsiloxysubstituted alkylphosphonites and their derivatives at mild conditions. Also the new functionalized derivatives of these phosphonites, including amino groups as well as certain properties of these compounds as important precursors of new functionalized 1-hydroxyalkylorganophosphorus acids, are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:352,359, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20430 [source]