Alkoxide variation in complex base-promoted syn dehydrohalogenations

Ndebeka, G.; Raynal, Serge; Caubère, P.; Bartsch, Richard A.

doi:10.1021/jo01314a045

Cited by 14 publications

(7 citation statements)

References 1 publication

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“…Initial coupling of a cyclopentenylzinc reagent with the acid chloride derived from 5 used an organometallic prepared from cyclopentenyl bromide. Following reports in the literature, preparation of this bromide is capricious at best and hazardous at worst …”

Section: Resultsmentioning

confidence: 99%

Asymmetric Synthesis and Stereochemical Assignment of RS-97613, a Potent Immunosuppressive and Antiinflammatory Agent

Smith¹,

Waltos²,

Loughhead³

et al. 1996

J. Org. Chem.

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Section: Resultsmentioning

confidence: 99%

Asymmetric Synthesis and Stereochemical Assignment of RS-97613, a Potent Immunosuppressive and Antiinflammatory Agent

Smith¹,

Waltos²,

Loughhead³

et al. 1996

J. Org. Chem.

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“…The low solubility of NaR in alkanes prevents the addition of more than one R group to CH 3 @1 . The partial or complete replacement of O t Bu groups in CH 3 @1 was achieved by another sodium alkoxide, sodium 1‐methylcyclohexanolate [45] [NaOMeCyc] (Scheme 3). The addition of NaOMeCyc to solutions of CH 3 @1 transformed the original methide singlet in the 1 H NMR by a new signal of apparently high‐multiplicity (e. g. nonet or higher), showing a striking resemblance to the 2 H NMR signal of Li 10 H(O t Bu) 9 and Li 12 H(O t Bu) 11 , caused by the coupling with 6 Li [36] .…”

Section: Resultsmentioning

confidence: 99%

Endohedral Mixed Aggregates: Sodium Alkoxide Cages with Organic or Inorganic Central Anions and Variable Hull

Cebi

Klett

2021

Chemistry A European J

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Alkali metal alkoxides are widely used in chemistry due to their Brønsted basic and nucleophilic properties. Potassium alkoxides assist alkyllithium in the metalation of hydrocarbons in Lochmann-Schlosser-bases. Both compounds form mixed aggregates, which enhance the thermal stability, solubility, and the basic reactivity of these mixtures. A very unusual spherical mixed alkoxy aggregate was discovered by Grützmacher et al., where a central dihydrogen phosphide anion is surrounded by a highly dynamic shell of thirteen sodium atoms and a hull of twelve tert-butoxide groups. This structural motif can be reproduced by a reaction of trimethylsilyl compounds of methane, halogens, or pseudo-halogens with excess sodium tert-butoxide. A nucleophilic substitution releases the corresponding anion, which is then encapsulated by the sodium alkoxide units. The compounds are soluble in hydrocarbon solvents, enabling studies of solutions by highresolution NMR spectroscopy and IR/Raman studies of the crystalline materials.

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“…Cyclohexene was chosen rather than saturated cyclo-hexane because the former has sp 2 geometry at the point of attachment, the same as the other analogues and the natural bases. Thus, we purchased 1-bromopyrene (1d) and prepared bromobenzoterthiophene 1b [22], 4bromo-1,1′:4′,1″ terphenyl (1c) [23], 4-bromostilbene (= 4-bromo-1,1′-(ethene-1,2diyl)bis[benzene]; 1e) [24], and 1-bromocyclohexene (1f) [25] according to literature procedures. The 5-bromo-2,2′: 4′,2″-terthiophene (1a) was prepared from 2-bromothiophene via 6 and 7 as shown in Scheme 2.…”

Section: Resultsmentioning

confidence: 99%

“…Thus, we purchased 1-bromopyrene (1d) and prepared bromobenzoterthiophene 1b [22], 4-bromo-1,1': 4',1'' terphenyl (1c) [23], 4-bromostilbene ( 4-bromo-1,1'-(ethene-1,2-diyl)bis[benzene]; 1e) [24], and 1-bromocyclohexene (1f) [25] according to literature procedures. The 5-bromo-2,2': 4',2''-terthiophene (1a) was prepared from 2-bromothiophene via 6 and 7 as shown in Scheme 2.…”

mentioning

confidence: 99%

Novel Nucleoside Analogues with Fluorophores Replacing the DNA Base

Strässler

Davis

Kool

1999

HCA

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We describe the preparation and fluorescence properties of a set of new nucleosides in which a known hydrocarbon or oligothiophene fluorophore replaces the DNA base at C(1) of the deoxyribose moiety (see 3a -f). These compounds are potentially useful as probes in the study of the structure and dynamics of nucleic acids and their complexes with proteins. In addition, they may find use as fluorescent labels for nucleic-acid-based biomedical diagnostics methods. The fluorophores conjugated to deoxyribose at C(1) in the α-D-form include terphenyl, stilbene, terthiophene, benzoterthiophene, and pyrene. Also included is a non-fluorescent spacer in which cyclohexene replaces the DNA base. The nucleosides are derived from brominated fluorophore precursors and Hoffer's 2-deoxy-3,5-di-O-(p-toluoyl)-D-ribofuranosyl chloride. The emission maxima of the free nucleosides range from 345 to 536 nm. Also described are the 5′-(dimethoxytrityl) 3′-O-phosphoramidite derivatives 5a -f, suitable for incorporation into oligonucleotides by automated synthesizers.We have taken a related approach to developing new fluorescent labels for DNA [10]. Rather than modifying an existing DNA base, however, we have simply replaced it by another flat aromatic structure, i.e.

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Alkoxide variation in complex base-promoted syn dehydrohalogenations

Cited by 14 publications

References 1 publication

Asymmetric Synthesis and Stereochemical Assignment of RS-97613, a Potent Immunosuppressive and Antiinflammatory Agent

Asymmetric Synthesis and Stereochemical Assignment of RS-97613, a Potent Immunosuppressive and Antiinflammatory Agent

Endohedral Mixed Aggregates: Sodium Alkoxide Cages with Organic or Inorganic Central Anions and Variable Hull

Novel Nucleoside Analogues with Fluorophores Replacing the DNA Base

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