Electrochemical Annulation of ortho‐Alkynylbiphenyls to Fused Sulfenyl Phenanthrenes and Spiro Cyclohexenone Indenes

Abstract

Here, we present an electrochemically induced synthesis of 9‐sulfenylarylphenanthrenes and 3’‐sulfenylarylspiro‐cyclohexa[4.5]trienones starting from o‐alkynylbiphenyls and diaryl disulfides. This method was accomplished through constant current electrolysis of 10 mA in an undivided cell setup by utilizing CH3CN as a solvent and LiClO4 as an electrolyte at room temperature. Notably, the present strategy enabled the formation of sulfenylphenanthrenes and sulfenyl spiro cyclohexa[4.5]trienones in 70%–95% yield. Scale‐up synthesis, mechanistic studies, and cyclic voltammetry have also been carried out.

Electrochemical selenofunctionalization of unactivated alkenes: access to β-hydroxy-selenides

“…32 Later, the research groups of Lie and Chen developed electrochemical techniques for oxyselenylation of styrenes by utilizing HFIP/CH 3 CN and CH 3 CN/H 2 O as solvent media for 4 h and 16 h, respectively (Scheme 1d). 33 Inspired by recent advances in the field of synthetic organic electrochemistry and issues associated with the prior conventional routes and our ongoing research interest in developing sustainable synthetic strategies, 34 here, we present a practical, affordable, and sustainable electrochemical approach to hydroxyselenylation of unactivated olefins using diaryl diselenides, in CH 3 CN solvent in an undivided cell (Scheme 1e). This method was amenable at ambient temperature without the requirement of an oxidant, a catalyst or an additive.…”