Diastereospecific Gold(I)-Catalyzed Cyclization Cascade for the Controlled Preparation of N- and N,O-Heterocycles

Michael E Muratore; Andrey I Konovalov; Helena Armengol-Relats; Antonio M Echavarren

doi:10.1002/chem.201802770

Diastereospecific Gold(I)-Catalyzed Cyclization Cascade for the Controlled Preparation of N- and N,O-Heterocycles

Chemistry. 2018 Oct 17;24(58):15613-15621. doi: 10.1002/chem.201802770. Epub 2018 Sep 21.

Authors

Michael E Muratore¹, Andrey I Konovalov¹, Helena Armengol-Relats^{1

2}, 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, C/ Marcel⋅lí Domingo s/n, 43007, Tarragona, Spain.

PMID: 30066978
DOI: 10.1002/chem.201802770

Abstract

The reaction of oxime-tethered 1,6-enynes with a cationic gold(I) catalyst demonstrates a great potential for the synthesis of a range of heterocycles in a diastereospecific fashion. The control of the configuration of the oxime and the alkene of the enyne moiety is the key to selectively obtain dihydro-1,2-oxazines, isoxazolines or dihydropyrrole-N-oxides as single diastereoisomers. As supported by DFT calculations, these cascade reactions proceed stepwise, by the intramolecular addition of the O or N atom of the oxime onto cyclopropyl gold(I) carbene intermediates. In this study, a rare [3,3]-sigmatropic rearrangement of nitrones is also observed.

Keywords: cascade reactions; cyclization; enynes; gold; oxazines; oximes.

Abstract

Grants and funding