Electrochemically modified Corey–Fuchs reaction for the synthesis of arylalkynes. The case of 2-(2,2-dibromovinyl)naphthalene

Abstract

The electrochemical reduction of 2-(2,2-dibromovinyl)naphthalene in a DMF solution (Pt cathode) yields selectively 2-ethynylnaphthalene or 2-(bromoethynyl)naphthalene in high yields, depending on the electrolysis conditions. In particular, by simply changing the working potential and the supporting electrolyte, the reaction can be directed towards the synthesis of the terminal alkyne (Et4NBF4) or the bromoalkyne (NaClO4). This study allowed to establish that 2-(bromoethynyl)naphthalene can be converted into 2-ethynylnaphthalene by cathodic reduction.

Alkynes as Building Blocks, Intermediates and Products in the Electrochemical Procedures Since 2000

“…The electrochemical processes leading to the synthesis of alkynes as final products are currently very few. In 2018, Feroci and co‐workers reported that 2‐(bromoethynyl)naphthalene can be cathodically converted to 2‐ethynylnaphthalene [9] . In a previous work, the same authors, reported the electrosynthesis of vinyl bromides starting from 1,1‐dibromo‐1‐alkenes: 2‐ethynylnaphthalene was obtained as main product (65 %) when the electrolysis was carried out at Au cathode in the absence of acetic acid as protonating agent [10] …”