Convenient synthesis of electron-donating substituted benzonitriles by photolysis of phenyl halides and esters

Irradiation of electron-donating substituted phenyl halides ( fluorides and chlorides) or esters (mesylates, triflates and phosphates) in aqueous MeCN in the presence of KCN gives the corresponding benzonitriles in 48 to 100% yield through an ArS(N)1 reaction with the intermediacy of a triplet phenyl cation.