Abstract
The transmetalation of the digold(I) complex [Au2Cl2(dcpm)] (1) (dcpm = bis(dicyclohexylphosphino)methane) with oligophenylene diboronic acids gave the triangular macrocyclic complexes [Au2(C6H4)x(dcpm)]3 (x = 3, 4, 5) with yields of over 70%. On the other hand, when the other digold(I) complex [Au2Cl2(dppm)] (1') (dcpm = bis(diphenylphosphino)methane) was used, only a negligible amount the triangular complex was obtained. The control experiments revealed that the dcpm ligand accelerated an intermolecular Au(I)–C σ-bond-exchange reaction, and that this high reversibility is the origin of the selective formation of the triangular complexes. Structural analyses and theoretical calculations indicate that dcpm ligand increases the electrophilicity of the Au atom in the complex, thus facilitating the exchange reaction, though cyclohexyl group is an electron-donating group. Furthermore, the oxidative chlorination of the macrocyclic gold complexes afforded a series of [n]cycloparaphenylenes (n = 9, 12, 15) in 78–88% isolated yields. The reaction of two different macrocyclic Au complexes gave a mixture of macrocyclic complexes incorporating different oligophenylene linkers, from which a mixture of [n]cycloparaphenylenes with various numbers of phenylene units was obtained in good yields.
Supplementary materials
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Supporting Information
Description
Supporting Information
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Title
CCDC2108728_Au-3
Description
CCDC2108728_Au-3
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Title
CCDC2108729_AuC-HH
Description
CCDC2108729_AuC-HH
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Title
CCDC2108730_Au-4_C2_What_Is_This
Description
CCDC2108730_Au-4_C2_What_Is_This
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Title
CCDC2108731_Au-4_D3
Description
CCDC2108731_Au-4_D3
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Title
CCDC2108732_AuC-FF
Description
CCDC2108732_AuC-FF
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Title
CCDC2108733_AuP-FF
Description
CCDC2108733_AuP-FF
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