Hydrotelluration of acetylenes: synthesis of vinylic tellurides, divinyl tellurides, and 1-(organyltelluro)-1,3-butadienes

Barros, S. M.; Dabdoub, Miguel J.; Dabdoub, V. M. B.; Comasseto, J. V.

doi:10.1021/om00109a014

Cited by 79 publications

(31 citation statements)

References 5 publications

(7 reference statements)

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“…Bis-vinylic tellurides can be prepared by reacting monosubstituted alkynes with a hydrotellurating system prepared from elemental tellurium and sodium borohydride in a mixture of ethanol / aqueous sodium hydroxide 15 . The stereochemistry of the resulting vinylic tellurides is also Z (Equation 2).…”

Section: Hydrotelluration Of Alkynesmentioning

confidence: 99%

Hydrotelluration of alkynes: a unique route to Z-vinyl organometallics

Vieira¹,

Zinn²,

Comasseto³

2001

J. Braz. Chem. Soc.

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A reação de hidroteluração de alquinos é revisada. A transformação de teluretos vinílicos em organometálicos vinílicos reativos e as reações de acoplamento de teluretos vinílicos com alquinos e organometálicos são apresentadas.The hydrotelluration reaction of alkynes is reviewed. The transformation of vinylic tellurides into reactive vinyl organometallics and the coupling reactions of vinylic tellurides with alkynes and organometallics are presented.

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Section: Hydrotelluration Of Alkynesmentioning

confidence: 99%

Hydrotelluration of alkynes: a unique route to Z-vinyl organometallics

Vieira¹,

Zinn²,

Comasseto³

2001

J. Braz. Chem. Soc.

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“…Isolated terminal alkyne 34 (Table 1, Entry 10), however, suffered loss of regioselectivity yielding 1,2-and 2,2-disubstituted vinylic tellurides 44 and 45, in favour of the 1,2-disubstituted vinylic telluride 44, as previously documented for isolated alkynes. 21,24,25 Unfortunately, in our case, an inseparable mixture was obtained. Efficient methodology to circumvent this problem, however, has been reported to regioselectively give the 1,2-disubstituted cis-vinylic tellurides by hydroboration or hydrometallation of 1-alkynyltellurides.…”

Section: Resultsmentioning

confidence: 58%

“…A variety of alkynes (i.e., 1) ( Table 1, [25][26][27][28][29][30][31][32][33][34] were treated with dibutyl ditelluride 2 and sodium borohydride under standard conditions 21,22 to give cis-vinyltellurides (i.e., 3) in 58-94% yield (Table 1, 35-43) (Scheme 1). For all conjugated alkynes, the cis-vinyltellurides were obtained with excellent regio-and stereo-selectivity.…”

Section: Resultsmentioning

confidence: 99%

“…18,19 Furthermore, in the case of di-and tri-stannylation and boration, the high control over stereochemistry is often lost. 7c,20 Considering that the hydrotelluration of alkynes occurs in a highly selective anti fashion to give cis-vinyltellurides that are not susceptible to isomerisation, 21 and also undergo transmetalation to give cis-vinyl metallated species (i.e., lithium, copper, zinc, magnesium, aluminium, calcium, and sodium) with retention of configuration, 22 we wondered whether this pre-existing methodology could be translated into a new synthetic method for cis-vinylstannanes and cis-vinylboronates. A vital pre-requisite of any new methodolgy in this area, in addition to being practical, reliable and stereoselective, would be accommodation of oxygen functionality.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of cis-vinyltrimethylstannanes and cis-vinylpinacolboronates in a two-step highly regio and stereoselective process

et al. 2009

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“…38,[61][62][63][64] Analysis of the 1 H NMR and 13 C NMR spectra showed that all alkene compounds presented data in full agreement with their assigned structures. The stereochemistry of the obtained alkenes was easily established.…”

Section: Resultsmentioning

confidence: 97%

Iron-catalyzed coupling reactions of vinylic chalcogenides with Grignard reagents

Silveira¹,

Mendes²,

Wolf³

2010

J. Braz. Chem. Soc.

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Este trabalho descreve um novo método para a reação de acoplamento entre selenetos e teluretos vinílicos e reagentes de Grignard, catalisada por Fe(acac) 3 e à temperatura ambiente. A reação ocorre com retenção da configuração, fornecendo os respectivos alquenos em bons a excelentes rendimentos. Este método também é eficiente para a reação de acoplamento de calcogenetos bisvinílicos com reagentes de Grignard.A general new method for the cross-coupling reaction between vinylic selenides and tellurides and Grignard reagents catalyzed by Fe(acac) 3 at room temperature is described. This reaction proceeded with retention of configuration, providing the respective alkenes in good to excellent yields. This method is also efficient for the coupling reaction of divinyl chalcogenides with Grignard reagents. Keywords: iron-catalyzed, vinylic chalcogenides, cross-coupling, Grignard reagents IntroductionOrganochalcogenium compounds became the key component of a variety of versatile and useful reagents for organic synthesis. The multiple applications of organochalcogenium chemistry have been well described in a number of review articles 1-6 and books. 7-11 Functionalized alkynyl 12-18 and alkenyl [19][20][21][22][23] chalcogenides have a great potential in organic synthesis, since they are valuable intermediates for the selective preparation of several organic compounds.Among the many applications of vinylic selenides, divinylic selenides and vinylic sulfides, the cross-coupling reaction with Grignard reagents catalyzed by Ni 18,24-27 and Pd 28,29 to give the corresponding cross-coupled products, has been described. On the other hand, Pd 19,30 and Ni 24,[31][32][33] catalyzed cross coupling reactions and tellurium/metal exchange reactions [34][35][36][37][38][39][40][41][42] are demonstrative of the usefulness of vinylic tellurides.Transition-metal-catalyzed C-C bond coupling reactions are very important in many areas of science. 43,44 Most current methods require expensive transitionmetal catalysts and ligands. However, in the last years Fe-catalyzed C-C bond cross coupling reactions of vinylic substrates and Grignard reagents became a subject of intense interest. [45][46][47][48][49][50][51] The vinylic counterpart is quite broad in scope, since vinylic halides, triflates, sulfonates, tosylates and enol phosphates can be used. [45][46][47][48][49][50][51] In continuation to our interest on the synthesis and synthetic applications of vinylic chalcogenides 52-58 we decided to study the feasibility of their use in cross coupling reaction with Grignard species catalyzed by iron. To the best of our knowledge, iron catalysts have never been used for the coupling of vinylic selenides and tellurides as electrophiles. The possible use of iron catalysts would represent a great improvement over the high cost of palladium precursors and from the concerns about the toxicity of nickel salts. In light of the above comments it is of interest to design a simple, efficient, and versatile method for the stereoselective coupling of vinylic se...

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Hydrotelluration of acetylenes: synthesis of vinylic tellurides, divinyl tellurides, and 1-(organyltelluro)-1,3-butadienes

Abstract: Organyltellurols generated in situ by NaBH4 reduction of diorganyl ditellurides react with acetylenes in refluxing ethanol to give vinylic tellurides of Z configuration.

Cited by 79 publications

References 5 publications

Hydrotelluration of alkynes: a unique route to Z-vinyl organometallics

Hydrotelluration of alkynes: a unique route to Z-vinyl organometallics

Synthesis of cis-vinyltrimethylstannanes and cis-vinylpinacolboronates in a two-step highly regio and stereoselective process

Iron-catalyzed coupling reactions of vinylic chalcogenides with Grignard reagents

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