On the Structure of Intermediates in Enyne Gold(I)-Catalyzed Cyclizations: Formation of trans-Fused Bicyclo[5.1.0]octanes as a Case Study

Imma Escofet; Helena Armengol-Relats; Hanna Bruss; Maria Besora; Antonio M Echavarren

doi:10.1002/chem.202004237

On the Structure of Intermediates in Enyne Gold(I)-Catalyzed Cyclizations: Formation of trans-Fused Bicyclo[5.1.0]octanes as a Case Study

Chemistry. 2020 Dec 1;26(67):15738-15745. doi: 10.1002/chem.202004237. Epub 2020 Nov 19.

Authors

Imma Escofet^{1

2}, Helena Armengol-Relats^{1

2}, Hanna Bruss^{1

2}, Maria Besora³, Antonio M Echavarren^{1

2}

Affiliations

¹ Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007, Tarragona, Spain.
² Departament de Química Orgànica i Analítica, Universitat Rovira i Virgili (URV), C/ Marcel⋅lí Domingo s/n, 43007, Tarragona, Spain.
³ Departament de Química Física i Inorgànica, Universitat Rovira i Virgili (URV), C/ Marcel⋅lí Domingo s/n, 43007, Tarragona, Spain.

Abstract

The nature of cyclopropyl gold(I) carbene-type intermediates has been reexamined as part of a mechanistic study on the formation of cis- or trans-fused bicyclo[5.1.0]octanes in a gold(I)-catalyzed cascade reaction. Benchmark of DFT methods together with QTAIM theory and NBO analysis confirms the formation of distinct intermediates with carbenic or carbocationic structures in the cycloisomerizations of enynes.

Keywords: DFT calculations; cycloisomerization; cyclopropanation; dienynes; gold(I) catalysis.

Abstract

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