ChemInform Abstract: SYNTHESIS OF DIALKYLACETYLENYLTIN ACYLATES

Klyuchinskii, S. A.; Aliev, I. M.; Zavgorodnii, V. S.; Петров, А. А.

doi:10.1002/chin.198304297

Cited by 2 publications

(3 citation statements)

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“…However, if the anion is externally stabilized by the organic substituent, it may have enough time and a lower barrier to rearrange before the protonation to occur as a syn addition (Scheme ). Such an addition has been shown to partially occur in reactions involving the anionic nucleophiles R 3 Sn − when one of the alkyne substituents is an aryl or an alkoxy group that can stabilize the vinyl anion by either π conjugation and/or electron withdrawing. − Thus, the reaction of Et 3 Sn − with methylphenylacetylene results in the nucleophile being exclusively bonded to the methyl side of the triple bond and the products from the anti and syn additions in a ratio of 4:1 . The reaction of the clusters with HCCPh most likely produced the cis isomer in higher yield, but for one reason or another, only the minor trans anion produced crystals.…”

Section: Resultsmentioning

confidence: 99%

Heteroatomic Deltahedral Zintl Ions of Group 14 and their Alkenylation

2009

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Reported is the synthesis of Ge(9-x)Sn(x) heteroatomic deltahedral Zintl ions and their alkenylation by reactions with alkynes. The nine-atom clusters are made either by extraction from mixed Ge/Sn precursors with nominal composition K(4)Ge(9-x)Sn(x) or by dissolution of mixtures of the corresponding binary precursors K(4)Ge(9) and K(4)Sn(9) in solvents with high dielectric constants such as DMF, DMSO, and acetonitrile. Reactions of the heteroatomic clusters with alkynes such as Me(3)SiC[triple bond]CSiMe(3), HC[triple bond]CCpr (Cpr = cyclopropyl), and HC[triple bond]CPh in ethylenediamine resulted in the following structurally characterized compounds with alkenylated heteroatomic clusters: [K-(2,2,2-crypt)](3)[GeSn(8)-CH=CH(2)].en.tol (1), triclinic, P1, a = 13.9220(3) A, b = 14.9788(3) A, and c = 21.5892(5) A, alpha = 94.2580(10) degrees , beta = 98.5210(10) degrees , and gamma = 98.4890(10) degrees , V = 4382.31(16) A(3), Z = 2; [K-(2,2,2-crypt)](4)[Ge(2)Sn(7)(CH=CH(2))(2)](2).en (2), monoclinic, P2(1)/c, a = 48.1883(15) A, b = 12.1551(4) A, and c = 21.4824(7) A, beta = 90.052(2) degrees , V = 12583.0(7) A(3), Z = 4; [K-(2,2,2-crypt)](3)[GeSn(8)-CH=CHCpr].en (3), monoclinic, P2(1)/c, a = 17.9132(9) A, b = 22.7967(11) A, and c = 21.6922(12) A, beta = 98.409(2) degrees , V = 8763.0(8) A(3), Z = 4; [K-(2,2,2-crypt)](3)[Ge(2)Sn(7)-CH=CHPh].2en (4), monoclinic, P2(1)/n, a = 13.2583(5) A, b = 47.0565(17) A, and c = 15.9978(6) A, beta = 111.536(2) degrees , V = 9284.1(6) A(3), Z = 4. The potassium countercations of the divinyl-substituted cluster in 2 were exchanged for tetrapropylammonium cations, and the resulting compound was also crystallized and structurally characterized: [Pr(4)N](4)[Ge(2)Sn(7)(CH=CH(2))(2)](2) (5), triclinic, P1, a = 11.6757(8) A, b = 18.8150(16) A, and c = 21.0608(17) A, alpha = 112.327(3) degrees , beta = 91.550(3) degrees , and gamma = 91.892(3) degrees , V = 4273.5(6) A(3), Z = 2. All clusters were also characterized in solution by electrospray mass spectrometry.

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Section: Resultsmentioning

confidence: 99%

Heteroatomic Deltahedral Zintl Ions of Group 14 and their Alkenylation

2009

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“…A number of strong anionic nucleophiles such as R 3 Ge − , R 3 Sn − , RSe − , RTe − , R 2 P − , etc. are known to attack the π* orbitals and add to various alkynes. − The resulting vinylic anions are then protonated stereoselectively trans to the added nucleophile (i.e., anti addition). Furthermore, the nucleophilic addition is regioselective and proceeds with terminal alkynes as well.…”

Section: Discussionmentioning

confidence: 99%

“…It should be pointed out that although to date we have observed only anti addition of clusters to alkynes, we do not rule out syn addition under someyet unknownconditions. Such addition has been shown to partially occur in reactions involving the anionic nucleophiles R 3 E − (E = Ge, Sn), − especially when the barrier to isomerization of the vinyl anion is low and/or the rate of protonation of the vinyl anion is particularly slow. Apparently, such conditions exist when the substituent at the β-carbon are phenyl or alkoxy groups that can stabilize the vinyl anion. , In general, Houk and Perrin expect this to be the case for alkynes with electron withdrawing substituents.…”

Section: Discussionmentioning

confidence: 99%

Functionalization of Nine-Atom Deltahedral Zintl Ions with Organic Substituents: Detailed Studies of the Reactions

Hull

Sevov

2009

J. Am. Chem. Soc.

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Presented are the results of a systematic investigation of the reactions of nine-atom deltahedral clusters of germanium (Zintl ions, Ge(9)(n-)) with alkynes and alkyl halides that result in alkenylation and alkylation of the clusters, respectively. The reaction pathways have been probed in depth using various, appropriately substituted alkynes and organic halides, including some typical mechanistic probes and radical clocks. The regioselectivity and stereoselectivity of the reaction with alkynes was examined by systematically varying the steric and electronic nature of the substituents. The studies showed that the Zintl clusters act as strong, anionic nucleophiles toward the alkynes and primary and secondary alkyl halides but, most likely, as electron donors in reactions with tertiary alkyl halides and halogenated olefins. The pentenyl and methylcyclopropyl functionalized clusters, [Ge(9)(C(5)H(9))](3-) and [Ge(9)(CH(2)CH(CH(2))(2))](2-), respectively, were crystallographically characterized in compounds with [K-crypt](+) countercations. All compounds were also analyzed by NMR and electrospray mass spectrometry.

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ChemInform Abstract: SYNTHESIS OF DIALKYLACETYLENYLTIN ACYLATES

Cited by 2 publications

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Heteroatomic Deltahedral Zintl Ions of Group 14 and their Alkenylation

Heteroatomic Deltahedral Zintl Ions of Group 14 and their Alkenylation

Functionalization of Nine-Atom Deltahedral Zintl Ions with Organic Substituents: Detailed Studies of the Reactions

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