PTC sulfanylation of some carboxylic acids derivatives activated by `alfa´-sulfonyl or `alfa´-sulfinyl group, in solid-liquid system - Wladislaw, Blanka; Marzorati, Liliana; Biaggio, Francisco Carlos; Donnici, Claudio Luis; Neves, Regina M A; Claro Júnior, Nélson Ferreira (Phosphorus, Sulfur, and Silicon and the Related Elements, 1997)