Nucleosides. X. Anhydronucleosides and Related Compounds Derived from 2',5'-Di-O-trityluridine<sup>1-3</sup>

Yung, Naishun C.; Fox, Jack J.

doi:10.1021/ja01475a022

Cited by 76 publications

(18 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that the trityl ether linkage can be readily cleaved in solution by using various acids, such as formic acid, [23] acetic acid, [24] TFA, [25] and hydrochloric acid. [26] In principle, we can combine the cleavage and washing into one step, simply by immersing the thin film in a selective washing solvent (which should be a good solvent for PEO but a nonsolvent for PS) containing a suitable cleaving agent. In the simplest case, one may use an acid, such as TFA or acetic acid, as both the cleaving agent and the washing solvent.…”

mentioning

confidence: 99%

Highly Ordered Nanoporous Thin Films from Cleavable Polystyrene‐block‐poly(ethylene oxide)

et al. 2007

View full text Add to dashboard Cite

Nanoporous polymer thin films produced from ordered block copolymer precursors have received considerable attention, because they can be used in many applications including templating, separation, catalysis, and sensors.[1] Since 1988, [2] various block copolymers have been used to prepare nanoporous thin films via the selective removal of degradable minor components from self-assembled block copolymers. For cylinder-forming block copolymers, selective etching of the cylindrical microdomain in an ordered block copolymer results in the formation of nanoscopic channels. Specially, if the etchable cylinders are orientated normal to the film surface, removal of the cylinders will lead to the nanolithographic masks used in block-copolymer lithography.[3]Currently, the generation of nanoporous materials from ordered block copolymers relies on a selective etching protocol that does not compromise the integrity of the matrix material. Ozonolysis, [2,4] UV degradation, [5,6] reactive ion etching (RIE), [7] and chemical etching [8] are the methods that are commonly used for the removal of minor components to create nanopores. However, the number of polymers that can be degraded under mild reaction conditions in the thin-film state is limited. The preparation of nanoporous thin films from block copolymers without a degradable component requires a rational design of the polymer. In principle, to generate nanopores from self-assembled block copolymers, it is not necessary to degrade the backbone bonds in the minor component;rather, a cleavage of the juncture between two immiscible blocks is sufficient. [9][10][11][12] Therefore, if one could put a cleavable juncture into a block copolymer; the cleavage will not depend on the chemical nature of the minor component and should be applicable to a much larger variety of block copolymers. Cleavage of the juncture point of block copolymer in the ordered state followed by removal of the minor component via selective solvents is therefore a very promising strategy for the generation of nanoporous structures. For most of the nanoporous polymer thin films prepared to date, one of the major problems is the lack of long-range order in the nanopore array, which prevents them from being used in applications where addressability is required (e.g., magnetic storage devices). Long-range order in thin films of the precursor block copolymers is a prerequisite for obtaining nanoporous materials with well-ordered pores. We have recently demonstrated that the solvent-annealing of thin films of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymers leads to highly ordered arrays of PEO cylinders oriented normal to the film surface.[13] The long-range lateral order and the orientation in the annealed PS-b-PEO thin films arise from the strong nonfavorable interactions between PS and PEO, enhanced mobility caused by the presence of solvent, as well as the directionality of solvent evaporation. The subsequent removal of the PEO domain will lead to nanoporous films with identical long-range...

show abstract

mentioning

confidence: 99%

Highly Ordered Nanoporous Thin Films from Cleavable Polystyrene‐block‐poly(ethylene oxide)

et al. 2007

View full text Add to dashboard Cite

show abstract

“…3',5'-Di-0-trityluridine was prepared from uridine bj the method of Yung and Fox (4). The isolation procedure was modified in that the 3',5'-and 2',5'-ditrityl mixture produced was separated by thick-layer chromatography using ether as developing agent.…”

Section: Methodsmentioning

confidence: 99%

Conversion of uridine 2′,3′-carbonates to anhydrouridines

Ogilvie¹,

Iwacha²

1969

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…In the first one, the bridge linkage may be shifted from one to another atom of the carbohydrate residue, without cleavage of the N-glycosylic bond. The first example of such a rearrangement has been reported by Young and Fox [37]: 2',5'-di-O-benzoyl-O 2 ,3'-cyclouridine has been converted to its O 2 ,2'-cyclic isomer upon heating.…”

Section: Transglycosylation Of Pyrimidine Cyclonucleosidesmentioning

confidence: 98%

“…Therefore, the atom N9 of purine attacks C1 of a carbohydrate 1,2-acyloxonium ion (7) to form a 3,9-bis-glycosyl intermediate (36). The compound (36) is unstable, both for steric and electronic reasons, and undergoes decomposition to the thermodynamic product, 9-substituted regioisomer (37), with liberation of sugar cation (7).…”

Section: Purine Nucleosides 41 N N Transglycosylation: Adenosinementioning

confidence: 99%

“…When heating was continued for a longer time, the 9-regioisomer (37) was the only remaining product. The isolated product [(39); in its desilylated form] could be quantitatively isomerized to (37) in the presence of p-toluenesulfonic acid upon refluxing in chlorobenzene. This shows clearly that 7-riboadenine is a kinetic product in the ribosylation of adenine.…”

Section: Purine Nucleosides 41 N N Transglycosylation: Adenosinementioning

confidence: 99%

See 1 more Smart Citation

Reactions of Transglycosylation in the Nucleoside Chemistry

Boryski

2008

COC

View full text Add to dashboard Cite

Nucleosides. X. Anhydronucleosides and Related Compounds Derived from 2',5'-Di-O-trityluridine^1-3

Cited by 76 publications

References 1 publication

Highly Ordered Nanoporous Thin Films from Cleavable Polystyrene‐block‐poly(ethylene oxide)

Highly Ordered Nanoporous Thin Films from Cleavable Polystyrene‐block‐poly(ethylene oxide)

Conversion of uridine 2′,3′-carbonates to anhydrouridines

Reactions of Transglycosylation in the Nucleoside Chemistry

Contact Info

Product

Resources

About

Nucleosides. X. Anhydronucleosides and Related Compounds Derived from 2',5'-Di-O-trityluridine1-3

Cited by 76 publications

References 1 publication

Highly Ordered Nanoporous Thin Films from Cleavable Polystyrene‐block‐poly(ethylene oxide)

Highly Ordered Nanoporous Thin Films from Cleavable Polystyrene‐block‐poly(ethylene oxide)

Conversion of uridine 2′,3′-carbonates to anhydrouridines

Reactions of Transglycosylation in the Nucleoside Chemistry

Contact Info

Product

Resources

About

Nucleosides. X. Anhydronucleosides and Related Compounds Derived from 2',5'-Di-O-trityluridine^1-3