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. 2018 Mar 12;37(5):781-786.
doi: 10.1021/acs.organomet.7b00668. Epub 2017 Dec 19.

Role of σ,π-Digold(I) Alkyne Complexes in Reactions of Enynes

Sofia Ferrer  1 , Antonio M Echavarren  1   2
Affiliations

Role of σ,π-Digold(I) Alkyne Complexes in Reactions of Enynes

Sofia Ferrer et al. Organometallics. .

Abstract

Gold(I) acetylide and σ,π-digold(I) alkyne complexes derived from one prototypical 1,6-enyne and from 7-ethynyl-1,3,5-cycloheptatriene have been prepared and structurally characterized. Their possible role in gold(I)-catalyzed cycloisomerizations has been studied by experiment and by DFT calculations. Gold(I) acetylides are totally unproductive complexes in the absence of Brønsted acids. Similarly, no cyclizations were observed by heating σ,π-digold(I) alkyne digold(I) at least up to 130 °C. Theoretical studies provide a rationale for the much lower reactivity of digold species in reactions of enynes.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Scheme 1
Scheme 1. Formation of σ,π-Digold(I) Alkyne Complexes 3 from π-Gold(I) Alkyne Gold(I) Complexes 1
Scheme 2
Scheme 2. Proposed Role of gem-Diaurated Species in the Gold(I)-Catalyzed Cycloisomerization of 1,5-Allenynes
Scheme 3
Scheme 3. Cycloisomerizations of 1,6-Enyne 9 and 7-Ethynyl-1,3,5-cycloheptatriene 11
Figure 1
Figure 1
Acetylide gold(I) and σ,π-digold(I) alkyne complexes 13–19 (CHT = cycloheptatriene).
Figure 2
Figure 2
ORTEP plots (50% thermal ellipsoids) for gold(I) acetylide 15 and σ,π-alkyne digold(I) Complex 16. The SbF6– anion of 16 is omitted for clarity.
Figure 3
Figure 3
Complexes 20 and 21.
Scheme 4
Scheme 4. Cycloisomerizations of Monogold (Ia–c) and Digold 1,6-Enyne (IVa–c) Complexes,
Free energies in kcal/mol. The energy of TSIVc-VIc was calculated by freezing the following distance: d(C8–C55).
Scheme 5
Scheme 5. Cycloisomerizations of Monogold (IXa–c) and Digold Cycloheptatriene (XIIa–c) Complexes
Free energies in kcal/mol.
Scheme 6
Scheme 6. Cycloisomerizations of Monogold (XVa–c) and Digold 1,5-Allenyne (XVIIIa–c) Complexes,
Free energies in kcal/mol. The energy of TSXVIIIc-XIXc was calculated by freezing the following distances: d(C1–C79) and d(C1–C80).
See this image and copyright information in PMC

References

    1. Nesmeyanov A. N.; Perevalova E. G.; Grandberg K. I.; Lemenovskii D. A.; Baukova T. V.; Afanassova O. B. J. Organomet. Chem. 1974, 65, 131–144. 10.1016/S0022-328X(00)83895-4. - DOI
    2. Porter K. A.; Schier A.; Schmidbaur H. Organometallics 2003, 22, 4922–4927. 10.1021/om030575f. - DOI
    1. Braun I.; Asiri A. M.; Hashmi A. S. K. ACS Catal. 2013, 3, 1902–1907. 10.1021/cs400437s. - DOI
    1. Gómez-Suárez A.; Nolan S. P. Angew. Chem., Int. Ed. 2012, 51, 8156–8159. 10.1002/anie.201203587. - DOI - PubMed
    1. Seidel G.; Lehmann C. W.; Fürstner A. Angew. Chem., Int. Ed. 2010, 49, 8466–8470. 10.1002/anie.201003349. - DOI - PubMed
    2. Hooper T. N.; Green M.; Russell C. A. Chem. Commun. 2010, 46, 2313–2315. 10.1039/b923900f. - DOI - PubMed
    3. Brown T. J.; Widenhoefer R. A. Organometallics 2011, 30, 6003–6009. 10.1021/om200840g. - DOI
    4. Brown T. J.; Widenhoefer R. A. J. Organomet. Chem. 2011, 696, 1216–1220. 10.1016/j.jorganchem.2010.09.055. - DOI - PMC - PubMed
    1. Lima J. C.; Rodriguez L. Chem. Soc. Rev. 2011, 40, 5442–556. 10.1039/c1cs15123a. - DOI - PubMed