The hydroarylation of alkenes has emerged as a powerful strategy for arene functionalization. However, aryl chlorides remain a large challenge in this type of reaction due to the chemical inertness of the C(sp2)–Cl bond and high negative reduction potential. Herein, we report an anti-Markovnikov radical hydroarylation of alkenes with aryl chlorides via visible-light photoredox catalysis. The key reactive
Aryl radicals from electrochemical reduction of aryl halides. Addition on olefins
作者:Zoubida Chami、Monique Gareil、Jean Pinson、Jean Michel Saveant、Andre Thiebault
DOI:10.1021/jo00002a020
日期:1991.1
Aryl radicals generated by direct and indirect (by means of an aromatic anion radical mediator) electrochemistry are reacted with olefins in liquid ammonia and in organic solvents (Me2SO, MeCN, DMF). The arylated product is obtained in good yield in the latter case. In pure liquid NH3, the yields are extremely poor. They are improved upon addition of a proton donor such as urea or water; further increase of yields is obtained upon addition of 2-propanol. A reaction mechanism is proposed based on these observations and on the results of deuterium incorporation experiments. Cyclic voltammetry is used to determine the rate constant of the key step in the mechanism, viz, the addition of the aryl radical to the olefin, through its competition with its reaction with nucleophiles in the framework of an S(RN)1 substitution process.