Reductive Cyclization of o-(3-Butenyl)fluorobenzene at Mercury and Lead Cathodes

Article abstract of DOI:10.1021/jo00286a030

The cathodic behavior of o-(3-butenyl)fluorobenzene (1) at mercury and lead cathodes in DMF was investigated.Cyclic voltammograms were recorded, and the products of preparative electrolyses were isolated and identified.The reduction products at either cathode were 1-methylindane (3) and 3-butenylbenzene (2), the first predominating in all experiments with dry solvent.The effects of various reaction conditions on the product composition were studied, and the highest yield of 3 was obtained at a lead cathode at 22 deg C (3/2 = 3.8).Dimethylpyrrolidinium (DMP⁺) was tested as a possible catalyst for the reduction of 1.It catalyzed the reaction and increased the proportionate amount of the cyclic product.However the mediated process at lead was very inefficient.The mechanism for the reductive cyclization of 1 at mercury and lead and the mediation by DMP⁺ are discussed.It is proposed that tetraalkylammonium-metals are involved in these processes.