AbstractThe reaction of the bromo‐substituted naphthalene1with the alkanethiolate anions2a–band arenethiolate2cin tetraglyme gave the corresponding 1‐naphythyl thio‐ethers3a–c. Thio‐ethers3a–cwere oxidized to the corresponding sulfones4a–cwithm‐ chloroperoxybenzoic acid. The reaction of the dichloro‐substituted anthracene5awith2bgave the disubstutution product6a.The reaction of 9‐bromoanthracene5cwith the alkanethiolate2bgave6b, whereas the reaction of5cwith the arenethiolate2cgave a mixture of substitution product6cand anthracene7.The observation of the formation of both6cand7is explained by the competition between substitution (SnAr) and electron‐transfer (ET) mechanisms. Consistent with this interpretation, the reaction of the monochloro‐substituted5b, which has a higher‐energy σ*orbital, with2cgave6cwithout the formation of7.Zn/KOH in tetraglyme was shown to reduce the aryl ha