Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

Sergey V Norkov; Anton V Cherkasov; Andrey S Shavyrin; Maxim V Arsenyev; Viacheslav A Kuropatov; Vladimir K Cherkasov

doi:10.3762/bjoc.17.26

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

Beilstein J Org Chem. 2021 Jan 27:17:273-282. doi: 10.3762/bjoc.17.26. eCollection 2021.

Authors

Sergey V Norkov^{1

2}, Anton V Cherkasov^#¹, Andrey S Shavyrin^#¹, Maxim V Arsenyev^#¹, Viacheslav A Kuropatov¹, Vladimir K Cherkasov^#¹

Affiliations

¹ G. A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Tropinina str. 49, Box-445, 603950 Nizhny Novgorod, Russia.
² N. I. Lobachevsky Nizhny Novgorod State University, 23 Gagarin Ave, 603950, Nizhny Novgorod, Russia.

^# Contributed equally.

Abstract

The fused 1,3-dithiole spacer seems to be very suitable for the functionalization of sterically hindered o-quinones with additional groups capable of coordination of metal ions and/or possessing a redox activity. An effective method for the synthesis of sterically hindered o-quinones containing 1,3-diketonate, dinitrile and p-quinone-methide functional groups at the periphery of the ligand has been developed. The novel compounds have rigid and conjugated structures and exhibit properties typical of o-quinones. A study of their monoreduced semiquinone derivatives reveal that the spin density is delocalized across the whole molecule, including peripheral fragments. The first stable o-quinone derivative bearing an annulated thiete heterocycle has been isolated and characterized.

Keywords: 1,3-dithiole; dioxolene ligand; ditopic ligand; o-quinone; thiete.

Grants and funding

This work was supported by RFBR according to the research project № 19-29-08039-mk and in the framework of the Russian state assignment. The X-ray diffraction, EPR, NMR spectroscopy study of 6a–d and 7–9 has been carried out in the framework of the Russian state assignment using the equipment of “Analytical Center of the IOMC RAS” with the financial support of the Federal objective program “Research and development in priority directions of advancement of science and technology complex of Russia for 2014-2020” (Unique project identifier is RFMEFI62120X0040).