A highly stereoselective synthesis of vinyl bromides and chlorides via disubstituted vinylsilanes

Miller, Rebecca; McGarvey, Glenn J.

doi:10.1021/jo00417a006

Cited by 130 publications

(49 citation statements)

References 10 publications

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“…Also, (1,2,2-trichloroethyl)benzene 6 (1%) was isolated from the reaction catalyzed by VO(acac) 2 , unlike the reaction run under other conditions. The structures of 1-6 were confirmed by IR and NMR spectroscopy; the characteristics of the compounds synthesized corresponded to the published data [23][24][25][26][27].…”

Section: Doi: 101134/s1070363218040308supporting

confidence: 69%

Reaction of Styrene with Chlorine Dioxide

2018

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Section: Doi: 101134/s1070363218040308supporting

confidence: 69%

Reaction of Styrene with Chlorine Dioxide

2018

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“…The aldehyde 8 is almost instantaneously deoxygenated by the catechyl phosphorus tribromide 64 (Scheme ), which is approved48 for the preparation of 1,1‐dibromides such as the desired t Bu 2 CH–CHBr 2 . However, the repulsive strain inherent in the gem ‐ t Bu 2 fragment appears to lead 8 away from the intended course, producing instead the de‐ tert ‐butylated alkenyl bromide 65 as the pure ( Z ) isomer,49 which was slowly converted into the ( E ) isomer 66 under the reaction conditions.…”

Section: Resultsmentioning

confidence: 99%

Shorter and Easier Syntheses of Di‐tert‐butylketene and Relatedgem‐Di‐tert‐butyl Compounds

Knorr¹,

Hennig²,

Schubert³

et al. 2010

Eur J Org Chem

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The ketene tBu2C=C=O is prepared from tBu2C=O in three steps (performable as a two‐stage operation) through elimination of HCl from the intermediate product tBu2CCl–CH=O. The acid tBu2CH–CO2H, obtainable in two, three, or four preparative stages from tBu2C=O, adds slowly to the ketene to produce the anhydride (tBu2CH–CO)2O. Elemental lithium together with ClSiMe3 converts tBu2CCl–CH=O into tBu2C=CH–OSiMe3, which is a durable precursor of tBu2CH–CH=O, making this aldehyde easily and cheaply available from tBu2C=O. By exclusion of alternative mechanistic possibilities, the reduction of tBu2CCl–CH=O by tBuMgCl is shown to involve at least one single‐electron transfer, leading to the enolate tBu2C=CH–OMgCl, which can be converted into tBu2CH–CH=O (three steps from tBu2C=O) or into tBu2C=CH–OSiMe3. Hydride transfer from NaBH4 to tBu2CCl–CH=O affords tBu2CCl–CH2OH, the transformations of which provide an entertaining set of SN1‐type reactions. Several other examples of carbenium‐type behavior are encountered in this gem‐tBu2 system; they are attributed to steric congestion, which also impedes bond rotations in the anhydride and in two esters. A convenient route to tBu2CH–C≡N (five steps from tBu2C=O) uses the conversion of tBu2C=CH–OSiMe3 into tBu2CH–CH=NOH. The slow thermal (Z)/(E) equilibration of tBu2CH–NH–CH=O reveals the ranking of ecliptic repulsions as H3C < tBu < tBu2CH.

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“…In contrast, reaction of the (E)-5-(2-trimethylsilylvinyl) compound 6b with Br 2 or BrCl, under similar (27) reported that halogenation of trans-β-trimethylsilylstyrene in CH 2 Cl 2 at low temperature proceeds via a silicon-stabilized cationic species, which upon attack by a halide anion would afford a dihalide adduct that is formally the product of cis-halogenation. Exclusive formation of the (E)−CH=CH−Br product 7b is likely due to stabilization of the silicon-bridged cationic species at −78 • C and the effect of the phenyl moiety (27). 2) (27,28).…”

Section: Chemistrymentioning

confidence: 98%

SYNTHESIS OF 1-(2-DEOXY-β-D-RIBOFURANOSYL)-2,4-DIFLUORO-5-SUBSTITUTED-BENZENES^*: “THYMINE REPLACEMENT” ANALOGS OF THYMIDINE FOR EVALUATION AS ANTICANCER AND ANTIVIRAL AGENTS

Wang¹,

Duan²,

Wiebe³

et al. 2001

Nucleosides, Nucleotides and Nucleic Acids

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A group of unnatural 1-(2-deoxy-beta-D-ribofuranosyl)-2,4-difluorobenzenes having a variety of C-5 two-carbon substituents [-C...C-X, X = I, Br; -C...CH; (E)-CH=CH-X, X = I, Br; -CH=CH2; -CH2CH3; -CH(N3) CH2Br], designed as nucleoside mimics, were synthesized for evaluation as anticancer and antiviral agents. The 5-substituted (E)-CH=CH-I and -CH2CH3 compounds exhibited negligible cytotoxicity in a MTT assay (CC50 = 10(-3) to 10(-4)M range), relative to thymidine (CC50 = 10(-3) to 10(-5)M range), against a variety of cancer cell lines. In contrast, the C-5 substituted -C...C-I and -CH(N3)CH2Br compounds were more cytotoxic (CC50 = 10(-5) to 10(-6)M range). The -C...C-I and -CH2CH3 compounds exhibited similar cytotoxicity against non-transfected (KBALB, 143B) and HSV-1 TK+ gene transfected (KBALB-STK, 143B-LTK) cancer cell lines expressing the herpes simplex virus type 1 (HSV-1) thymidine kinase gene (TK+). This observation indicates that expression of the viral TK enzyme did not provide a gene therapeutic effect. The parent group of 5-substituted compounds, that were evaluated using a wide variety of antiviral assay systems [HSV-1, HSV-2, varicella-zoster virus (VZV), vaccinia virus, vesicular stomatitis, cytomegalovirus (CMV), and human immunodeficiency (HIV-1, HIV-2) viruses], showed that this class of unnatural C-aryl nucleoside mimics are inactive and/or weakly active antiviral agents.

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A highly stereoselective synthesis of vinyl bromides and chlorides via disubstituted vinylsilanes

Cited by 130 publications

References 10 publications

Reaction of Styrene with Chlorine Dioxide

Reaction of Styrene with Chlorine Dioxide

Shorter and Easier Syntheses of Di‐tert‐butylketene and Relatedgem‐Di‐tert‐butyl Compounds

SYNTHESIS OF 1-(2-DEOXY-β-D-RIBOFURANOSYL)-2,4-DIFLUORO-5-SUBSTITUTED-BENZENES^*: “THYMINE REPLACEMENT” ANALOGS OF THYMIDINE FOR EVALUATION AS ANTICANCER AND ANTIVIRAL AGENTS

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A highly stereoselective synthesis of vinyl bromides and chlorides via disubstituted vinylsilanes

Cited by 130 publications

References 10 publications

Reaction of Styrene with Chlorine Dioxide

Reaction of Styrene with Chlorine Dioxide

Shorter and Easier Syntheses of Di‐tert‐butylketene and Relatedgem‐Di‐tert‐butyl Compounds

SYNTHESIS OF 1-(2-DEOXY-β-D-RIBOFURANOSYL)-2,4-DIFLUORO-5-SUBSTITUTED-BENZENES*: “THYMINE REPLACEMENT” ANALOGS OF THYMIDINE FOR EVALUATION AS ANTICANCER AND ANTIVIRAL AGENTS

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Product

Resources

About

SYNTHESIS OF 1-(2-DEOXY-β-D-RIBOFURANOSYL)-2,4-DIFLUORO-5-SUBSTITUTED-BENZENES^*: “THYMINE REPLACEMENT” ANALOGS OF THYMIDINE FOR EVALUATION AS ANTICANCER AND ANTIVIRAL AGENTS