3 edition of Synthesis and reactions of protected aminoacyl ethyl phosphates found in the catalog.
Synthesis and reactions of protected aminoacyl ethyl phosphates
Peter C. Spencer
Thesis (M.Sc.) -- University of Toronto, 1998.
|Series||Canadian theses = -- Thèses canadiennes|
|The Physical Object|
|Pagination||1 microfiche : negative. --|
A The Aldol Addition. A most important property of enolate anions, at least as far as synthesis is concerned, is their excellent nucleophilicity, which enables them to add to double bonds and to participate in nucleophilic substitution. When the addition is to a carbonyl double bond, it is called an aldol addition (Equation ). Additions of enolate anions to carbon-carbon double bonds. Synthesis of Some Derivatives with Respect to the Phosphate Group. In reactions involving nucleotides, the heterocyclic base, as well as hydroxyl groups of pentose and the phosphate group may be affected. For reactions to proceed selectively with respect to the phosphate group, the latter must be activated. To this end, use is made of carbodiimides, aryl sulfochlorides, and diphenylchlorophosphate.
The aminoacyl esters are formed by transfer of the aminoacyl moieties from aminoacyl phosphates (in the form of aminoacyl adenylates) to the 3′ ends of adaptors (tRNAs) in reactions catalyzed by aminoacyl-tRNA synthetases (7–9). With this transfer reaction in mind, we envisioned a scenario where the ester was eliminated and the high energy of the aminoacyl phosphate was Cited by: Reaction with nitrous acid. Nitrous acid is unstable and must be prepared in the reaction solution by mixing sodium nitrite with acid. Primary amines react with nitrous acid to yield a diazonium salt, which is highly unstable and degradates into a carbocation that is capable of reaction .
For the synthesis of N 6-alkylated compounds, initially, we attempted to introduce various N 6-alkyl groups at the pre-final protected stage by nucleophilic aromatic substitution on the C 6-position. However, we observed no reaction or degradation of the protected 6-chloropurine ISA : Manesh Nautiyal, Bharat Gadakh, Steff De Graef, Luping Pang, Masroor Khan, Yi Xun, Jef Rozenski, Art. select a protective group from those described in this book, and an illustrative exam- ple of the use of protective groups in a synthesis of brefeldin. The book is organized by functional group to be protected. At the beginning of each chapter are listed the possible protective groups.
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Aminoacyl ethyl phosphates react with amines and alcohols, making them excellent candidates for potential use in aqueous peptide synthesis and the chemical aminoacylation of t-RNA.
Aminoacyl ethyl phosphates can be produced by using dicyclohexylcarbodiimide to couple N-protected amino acids with tetraethylammonium ethyl : Peter C.
Spencer. Aminoacyl ethyl phosphates react with amines and alcohols, making them excellent candidates for potential use in aqueous peptide synthesis and the chemical aminoacylation of : Peter C. Spencer. Aminoacyl ethyl phosphates are functional analogues of aminoacyl adenylates, the activated intermediates formed by ribosomal enzymes from the reaction of amino acids with ATP.
The aminoacyl ethyl phosphates are prepared by DCC-mediated coupling of a tetraalkylammonium salt of ethyl phosphate and an N - t -Boc-amino acid, followed by by: Abstract. The main impetus for the studies of the chemistry of the title compounds stems from the fact that the compounds from the aminoacyl transfer ribonucleic acid (aa-tRNA; see Section 11 for abbreviations used in this chapter), the key intermediate in the biosynthesis of by: 2.
Synthesis of ethyl 5‐amino‐4‐cyano‐1‐phenyl‐1H‐pyrazole‐3‐carboxylate 5 has been achieved via abnormal Beckmann rearrangement of o‐chloroaldehyde on of o‐aminocarbonitrile 5 with concentrated H 2 SO 4 furnished expected o‐aminocarboxamide pyrazole intermediates o‐aminocarbonitrile 5 and o‐aminocarboxamide 6 were successfully utilized for the synthesis Cited by: 2.
The first step is the formation of aminoacyl adenylates (I, Fig. 1) by a specific reaction involving amino acids, adenosine triphosphate, and an aminoacyl-tRNA synthetase. The amino acids are thus activated and subsequently transferred to their corresponding tRNA through a highly specific reaction catalyzed by the same by: 7.
Aminoacyl ethyl phosphates are functional analogues of aminoacyl adenylates, the activated intermediates formed by ribosomal enzymes from the reaction of amino acids with ATP. Detection of metaphosphate intermediates in reaction solutions of phosphate esters: Chromatographic and spectroscopic studies.
Phosphorus, Sulfur, and Silicon and the Related Elements(10), DOI: /Cited by: A Mild Preparation of Protected Phosphate Esters From Alcohols. The Journal of Organic Chemistry60 Bader Award Lecture Aminoacyl ethyl phosphates. Biomimetically activated amino acids. Canadian Journal of Chemistry74 Cyanamide-induced condensation reactions of Cited by: Chiral N-Boc- and Cbz-protected (α-aminoacyl)benzotriazoles 6a−g microwaved for 10 minutes with ethyl (triphenylphosphoranylidene)acetate 7 produce chiral phosphorus ylides 8a−g in 65−90% yield.
Reactions of diastereomeric chiral phosphorus ylides (15, 16) demonstrated preservation of chirality. ethyl)acid phosphate (acryl phosphate), was synthesized through the reaction of 2-hydroxyethyl methacrylate with phosphorus pentoxide, and then it was copolymerized with methyl methacrylate, which provides long-term antistatic properties without losing the PMMA bulk properties signif-icantly Lynen (5) first described the synthesis of monoacetyl phosphate.
This was prepared by the reaction of silver dibenzyl phosphate with acetyl chloride, followed by removal of the benzyl groups as toluene by catalytic hydrogenolysis. Lipmann and Tuttle (6) recently published a much more.
Aminoacyl-nucleotide anhydrides are synthesised in high yield by treating the ethyl carbonate anhydride of a protected amino acid with the nucleoside 5′-phosphate.
The synthesis of ethyl carbonate anhydrides of nucleoside 5′-phosphate is also by: Macrocyclic tetraphosphine oxides are obtained by cyclisation of phenyl[2-(phenylphosphino)ethyl]phosphine copper(I) triflate with an alkyl or aryl bis-halide followed by demetallation with H 2 S. The procedure is effective even if the metal chelate features five and six-membered rings and is more readily applicable than multi-step non-template by: Reaction of Boc-protected amino acids with 3-phenoxytrifluoromethylchromones gave new, previously unknown aminoacyl derivatives.
Discover the world's research 17+ million members. Recent Literature. A low catalyst loading of [Cp*IrCl 2] 2 in the presence of t-BuOK enables a simple and versatile N-alkylation of sulfonamides with various alcohols based on a catalytic hydrogen transfer s N-alkylated sulfonamides were prepared in good to excellent yields.
Key catalytic species is a sulfonylimido-bridged unsaturated diiridium complex [(Cp*Ir) 2 (μ-NTs) 2]. 1 Protection Reactions Vommina V. Sureshbabu and Narasimhamurthy Narendra General Considerations order to obtain a Na-protected peptide acid or to regenerate a side-chain functional not withstanding methyl and ethyl esters (which are susceptible to saponiﬁcation).File Size: 2MB.
Schmidt, Marika; Knölker, Hans-Joachim: Transition Metals in Organic Synthesis, Part Palladium-Catalyzed Approach to 2,6-Dioxygenated Carbazole Alkaloids - First Total Synthesis. The use of phosphorus pentaoxide for peptide synthesis was also reported, but racemization could occur under these reaction conditions [10–11].
Phosphorus oxychloride was another condensing agent used to synthesize various N-protected aminoacyl-pNAs in yields between 70% and 90%. The proposed mechanism implies in situ activation of carboxylic acid by formation of the active mixed anhydride Cited by: 6. ACETYL PHOSPHATE SYNTHESIS BY REACTION OF ISOPRO- PENYL ACETATE AND PHOSPHORIC ACID BY E.
STADTMAN* AND FRITZ LIPMANN (From the Biochemical Research Laboratory, Massachusetts General Hospital, and the Department of Biological Chemistry, Harvard Medical School, Boston) (Received for publication, Ma ).
Herein, we present an expeditious synthesis of novel N-substituted-1,4-dihydrooxoquinoline carboxylic acids derivatives in five steps from commercially available 2-bromo benzoic acid ().
Synthesis of ethyl(2-bromophenyl)((dimethylamino)methyl ene)oxopropanoate 2-bromo benzoic acid () was converted into corresponding acid. Tzvetkova S, Kluger R () Biomimetic aminoacylation of ribonucleotides and RNA with aminoacyl phosphate esters and lanthanum salts.
J Am Chem Soc (51)– CrossRef Google Scholar Cited by: Proline-catalyzed Mannich-type reactions of N-PMP-protected α-imino ethyl glyoxylate with a variety of unmodified aliphatic aldehydes provided functionalized α-amino acids in high yields with excellent enantioselectivities.
The diastereoselectivity of the reaction increased with the bulkiness of the substituents of the aldehyde donor.