Solvent-Free Synthesis and Key Intermediate Isolation in Ni2Dy2 Catalyst Development in the Domino Ring-Opening Electrocyclization Reaction of Furfural and Amines

Stavroula I Sampani; Andrew McGown; Alfredo Vargas; Alaa Abdul-Sada; Graham J Tizzard; Simon J Coles; John Spencer; George E Kostakis

doi:10.1021/acs.joc.9b00608

Solvent-Free Synthesis and Key Intermediate Isolation in Ni₂Dy₂ Catalyst Development in the Domino Ring-Opening Electrocyclization Reaction of Furfural and Amines

J Org Chem. 2019 Jun 7;84(11):6858-6867. doi: 10.1021/acs.joc.9b00608. Epub 2019 May 22.

Authors

Stavroula I Sampani¹, Andrew McGown¹, Alfredo Vargas¹, Alaa Abdul-Sada¹, Graham J Tizzard², Simon J Coles², John Spencer¹, George E Kostakis¹

Affiliations

¹ Department of Chemistry, School of Life Sciences , University of Sussex , Brighton BN1 9QJ , U.K.
² UK National Crystallography Service, Chemistry , University of Southampton , Southampton SO1 71BJ , U.K.

PMID: 31074278
DOI: 10.1021/acs.joc.9b00608

Abstract

A solvent-free methodology that yields trans-4,5-diaminocyclopent-2-enones, main domains of natural products and a variety of N-heterocycles, is described. The bimetallic catalyst [Ni^II₂Dy^III₂L₄(DMF)₆] 2(OTf) 2(DMF) (1) promotes the domino reaction of furfural and amines, with loadings as low as 0.01%, under stirring or microwave-assisted conditions to afford the corresponding frameworks in very good to excellent yields. Crystallographic and theoretical studies shed light on the exclusive formation of the trans-diastereoisomers via a 4π-conrotatory electrocyclization process elucidating the key step in the catalytic process.