https://zenodo.org/record/1259717/files/article.pdf

Advances in the Synthesis of Oligonucleotides by the Phosphoramidite Approach

The 2-5A system: modulation of viral and cellular processes through acceleration of RNA degradation.

The p-nitrophenylethyl (NPE) group: A versatile new blocking group for phosphate and aglycone protection in nucleosides and nucleotides

https://zenodo.org/record/1259719/files/article.pdf

Photolabile protecting groups for nucleosides: Synthesis and photodeprotection rates

Basen sind nach Losungsmitteln wohl die wichtigste Klasse von Hilfsstoffen fur die organische Synthase. Ihre Funktion ist oft nicht auf die diffusions-kontrollierte Protonen-Aufnahme beschrankt; gerade bei Reaktionen mit starken Metallbasen spielen strukturbestimmende Faktoren, wie Koordinations-Verhalten des Metall-Ions oder Aggregations-Verhalten des metallierten Substrats, eine oft entscheidende, wenn auch ebenso oft unzureichend verstandene, haufig gar unerwunschte Rolle.

Starke ungeladene Stickstoffbasen

XIV. Substituted β-Phenyl-ethyl Groups. New Blocking Groups for Oligonucleotide Syntheses by the Phosphotriester Approach



Various o- and p-substituted β-phenylethanols (2–10) have been synthesized and investigated as blocking groups in the phosphotriester approach. A large number of 5′-O-tritylated thymidine-3′-phosphotriesters (13–36) with two different phosphate protecting groups have been prepared, characterized, and studied according to their chemical stability and usefullness for oligonucleotide syntheses. The combination of a 5′-O-monomethoxytrityl- and a 3′-(2,5-dichlorophenyl, p-nitrophenylethyl)-phosphate function as in 18 turned out to possess optimal properties as a monomeric nucleotide building block due to the fact that these blocking groups can be quantitatively and selectively be removed without harming each other by trifluoroacetic acid in chloroform to 41, by oximate to 42, and by DBU to 43. The base-catalyzed removal of the monosubstituted phenylethyl groups by DBU or DBN respectively as well as the disubstituted phenylethyl groups by triethylamine in aprotic solvents is a β-elimination process leading to phosphodiesters without attack on the P-center.

Nucleotide. XIV. Substituierte β‐Phenyläthyl‐Gruppen. Neue Schutzgruppen für Oligonucleotid‐Synthesen nach dem Phosphorsäuretriester‐Verfahren

New improvements in oligonucleotide synthesis by use of the p-nitrophenylethyl phosphate blocking group and its deprotection by DBU or DBN

Nucleotide, XVI. Synthese und Eigenschaften von Adenylyl‐adenylyl‐adenosinen

The chemical synthesis of 3′-deoxyadenyly-(2′-5′)-3′-deoxyadenylyl-(2′-5′)-3′-deoxyadenosine (30; trimeric cordycepin) is described by three different routes using various protecting groups and applying the phosphotriester approach. The intermediates have been isolated and characterized by elemental analyses and spectroscopic means. High yields of 30 have been obtained on deprotection making this biologically very active compound available in preparative scale.

Nucleotides. Part XXVIII. Chemical syntheses of the 2′‐5′‐cordycepin‐trimer core

Nucleotides. XV. Synthesis and Properties of 2′O-t-Butyldimethylsilyl-5′-O-monomethoxytritylribonucleoside-3′-phosphotriesters, Starting Materials for Oligonucleotide Syntheses



The syntheses of two types of fully blocked ribonucleoside 3′-phosphotriesters 6–14 have been achieved in excellent yields from 2′-O-t-butyldimethylsilyl-5′-O-monomethoxytrityl-ribonucleosides 1–5 by phosphorylation with 2-chloro- and 2,5-dichlorophenylphosphorodichloridate respectively and subsequent treatment by cyanoethanol to 6, 8, 10, 12 and 14 and by p-nitrophenylethanol to 7, 9, 11 and 13. These phosphotriesters are valuable starting materials for oligonucleotide syntheses due to the fact that the corresponding phosphotriesters 15–23 with free HOC(5′) could be obtained by detritylation and the 3′-phosphodiester triethylammonium salts 24–32 by deblocking of the cyanoethyl and the 2,5-dichlorophenyl group respectively. All newly synthesized compounds have been characterized by UV.-and NMR.-spectra as well as C, H, N elementary analyses.

Nucleotide. XV. Synthese und Eigenschaften von 2′-O-t-Butyldimethylsilyl-5′-O-monomethoxytritylribonucleosid-3′-phosphotriestern, Ausgangssubstanzen für Oligonucleotid-Synthesen†

Eugen Uhlmann

Papers

Nucleotide. XIV. Substituierte β‐Phenyläthyl‐Gruppen. Neue Schutzgruppen für Oligonucleotid‐Synthesen nach dem Phosphorsäuretriester‐Verfahren

New improvements in oligonucleotide synthesis by use of the p-nitrophenylethyl phosphate blocking group and its deprotection by DBU or DBN

Nucleotide, XVI. Synthese und Eigenschaften von Adenylyl‐adenylyl‐adenosinen

Nucleotides. Part XXVIII. Chemical syntheses of the 2′‐5′‐cordycepin‐trimer core

Nucleotide. XV. Synthese und Eigenschaften von 2′-O-t-Butyldimethylsilyl-5′-O-monomethoxytritylribonucleosid-3′-phosphotriestern, Ausgangssubstanzen für Oligonucleotid-Synthesen†