Neue Reagenzien, XXVI. (Phenyltelluro)ethen, 1‐Lithio‐1‐(phenyltelluro)ethen und (Phenyltelluro)ethin, Synthese und Reaktionen

Kauffmann, Thomas; Ahlers, Holger

doi:10.1002/cber.19831160317

Cited by 46 publications

(2 citation statements)

References 17 publications

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“…For general background, see: Dabdoub et al (1998); Gillespie & Hargittai (1991); Kauffmann & Ahlers (1983); Murai et al (1994); Petragnani (1994); Potapov & Trofimov (2005);Schulz Lang et al (2006); Yoshimatsu (2005); Zukerman-Schpector & Haiduc (2001). For related structures, see: Farran et al (2002).…”

Section: Related Literaturementioning

confidence: 99%

“…We recently reported the syntheses and crystal structures of several symmetrical (R = R′) bis(aryltelluro)ethynes, Ar-Te-C≡C-Te-Ar (Farran et al, 2002). On the other hand, only five R-Te-C≡CH derivatives have been prepared so far, with R = Me, Et, i Pr, n-Bu and Ph (Kauffmann & Ahlers, 1983;Dabdoub et al, 1998;Potapov & Trofimov, 2005;Yoshimatsu, 2005), and none has been structurally characterized (in addition, molecular orbital calculations for R = HC≡C were carried out by Murai et al, 1994). Here we describe the crystal structure of the title compound (R = p-Me 2 NC 6 H 4 ), the first of an organyl ethynyl telluride to be reported.…”

Section: S1 Commentmentioning

confidence: 99%

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4-(Dimethylamino)phenyl ethynyl telluride

et al. 2009

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The title compound, C10H11NTe, is the first organyl ethynyl telluride, R—Te—C C—H, to be structurally characterized. In the L-shaped molecule, the aryl moiety, viz. Me2NC6H4Te, is almost perpendicular to the Te—C C—H fragment. The Te—Csp 2 bond [2.115 (3) Å] is significantly longer than the Te—Csp bond [2.041 (4) Å]. The Te—C C group is approximately linear [Te—C—C = 178.5 (4)° and C C = 1.161 (5) Å], while the coordination at the Te atom is angular [C—Te—C = 95.92 (14)°]. In the crystal structure, there are Csp—H⋯N hydrogen bonds which are perpendicular to the CNMe2 group; the N atom displays some degree of pyramidalization. Centrosymmetrically related pairs of molecules are linked by Te⋯π(aryl) interactions, with Te⋯Cg = 3.683 (4) Å and Csp—Te⋯Cg = 159.1 (2)° (Cg is the centroid of the benzene ring). These interactions lead to the formation of zigzag ribbons which run along c and are approximately parallel to (110).

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Section: Related Literaturementioning

confidence: 99%

Section: S1 Commentmentioning

confidence: 99%

4-(Dimethylamino)phenyl ethynyl telluride

et al. 2009

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The Role of Ate Complexes in Halogen(Metalloid)–Metal Exchange Reactions: A Theoretical Study

Boche¹,

Schimeczek

Ciosłowski³

et al. 1998

Eur. J. Org. Chem.

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Correlated electronic structure calculations predict that [(CH3)n+1X]− methyl ate anions, where X is an element of the main groups 14, 15, 16, or 17 up to Bi, possess widely varying stabilities that are governed by the electronegativities of their central atoms X. These stabilities correlate well with the propensities of the elements in question to undergo exchange with lithium and magnesium halide, except in the cases where steric hindrance in the transition states of the exchange reactions is important. These findings are nicely confirmed by calculations of the transition states [(CH3)2XLi]# (X = Cl, Br, I) and [(CH3)3SeLi]# of the corresponding degenerate exchange reactions CH3X (X = Cl, Br, I) + CH3Li and (CH3)2Se + CH3Li, respectively. The computed relative stabilities of the mixed [R–I–CH3]− ate anions of iodine (where R = phenyl, ethynyl, vinyl, ethyl, or cyclopropyl) are in excellent agreement with the experimentally observed equilibria of the corresponding lithium–iodine exchange reactions. The recent experimental observation of a highly stable α‐iodine‐substituted iodine ate complex as an intermediate in an iodine–magnesium bromide exchange reaction is also corroborated by our studies. Thus, the present calculations provide strong evidence for ate complexes being key intermediates in halogen(metalloid)–lithium(magnesium halide) exchange reactions.

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Relative rates, relative activation parameters and substituent effects of lithium-metalloid exchange reactions

Kanda

Katō

Kambe

et al. 1996

J. Phys. Org. Chem.

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The relative reactivity of heteroatomic compounds (PhM; M = SeR, SnR3, TeR, I) towards BuLi was estimated by competitive experiments. The rates of exchange reactions in THF increase in the order I > Te >> Sn >> Se with a ratio of 1000:300:15: 1 at -70 "C when R =Bu. Me,SnPh underwent exchange much faster than Bu,SnPh, suggesting that the exchange reaction was largely affected by steric hindrance. The evidence that Bu,SnPh and BuTePh react with BuLi at almost the same rate in the presence of HMPA and that the relative exchange rates of Li-Te/Li-Sn increase in less polar solvents such as Et10 and hexane indicates that coordination of solvents towards lithium plays an important role in exchange reactions. Relative activation parameters obtained from competitive reactions of PhTeBu and PhSnBu, with BuLi showed that Li-Te exchange was favored over Li-Sn exchange by an enthalpy factor. Hammett treatment of Li-Te exchange of ArTeBu with BuLi in THF showed a substantially large positive reaction constant ( p ) of 3.4, indicating that the anion charge was largely distributed on the leaving group in the transition state.

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Neue Reagenzien, XXVI. (Phenyltelluro)ethen, 1‐Lithio‐1‐(phenyltelluro)ethen und (Phenyltelluro)ethin, Synthese und Reaktionen

Cited by 46 publications

References 17 publications

4-(Dimethylamino)phenyl ethynyl telluride

4-(Dimethylamino)phenyl ethynyl telluride

The Role of Ate Complexes in Halogen(Metalloid)–Metal Exchange Reactions: A Theoretical Study

Relative rates, relative activation parameters and substituent effects of lithium-metalloid exchange reactions

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