Study On Two Palladium-Catalyzed Desulfitative Reactions

Transition-metal-catalyzed cross-coupling reaction is one of the most effective methods to construct the C-C bond and has been widely used in synthesis of natural products and pharmaceutical intermediates. Usually, transmetallations involve ruthenium, rhodiun, palladium, nickel, copper, silver, gold and so on. Among them, palladium is very important one in organic synthesis, because palladium as the catalyst represents high efficiency, little dosage and simple manipulation. During the past a few decades palladium-catalyzed cross-coupling reactions involving a series of classic reactions have been widely and thoroughly investigated. Recently, more and more attentions have been paid to discover novel palladium-catalyzed cross-coupling reactions. In this dissertation, we achieved palladium-catalyzed desulfitative reactions of arylsulfinic acids to construct new C-C bond.1. Palladium-catalyzed desulfitative Heck-type reaction of arylsulfinic acids with alkenes. Under the best conditions:10mol%of Pd(OAc)2,1equiv of Cu(OAc)2·H2O,1.5mL of dioxane,100℃,24h, we explored the scope and limitation of the reaction. A wide array of arylsulfinic acids could react with styrenes/acrylic derivatives to give the cross-coupling products with good to excellent yields. Meanwhile, Our method did not require a ligand or a base, further broadening the scope of Pd-catalyzed coupling reactions.2. Synthesis of ketones by palladium-catalyzed desulfitative reaction of arylsulfinic acids with nitriles. We developed an efficient protocol for the palladium(Ⅱ)-catalyzed desulfitative addition reaction of arylsulfinic acids with nitriles to afford a variety of aryl ketones in good to excellent yields in the presence of inexpensive2,2’-bipyridine as a ligand. This method provided a new venue for the rapid synthesis of various biaryl ketones and alkyl aryl ketones in one pot, further broadening the scope of synthesis of arylketones.