Thomas Lane Evans

Phase Transfer Controlled Selective Oxidation of Diarylsulfides to Diarylsulfoxides Using Potassium Hydrogen Persulfate

Abstract The use of biphasic reaction conditions and a phase transfer catalyst controls the oxidation reaction of potassium hydrogen persulfate with diarylsulfides yielding predominately sulfoxides. This is in contrast to the reaction in polar solvents where sulfones are the major products.

Phase Transfer Catalyzed Melt Synthesis of Diaryl Sulfides

Abstract The phase transfer catalyzed interaction of sodium sulfide with molten aryl halides is described. The yields of diaryl sulfide are greater than 50% when activating groups such as cyano, nitro, phthalimido, and anhydrido are present on the aromatic ring. In the absence of these activating groups the yields are less than 2%. The effect of parameters such as reaction temperature, reactant concentration and the nature of the phase transfer catalyst on the reaction yields are also reported. This procedure is especially useful for activated substrates that are sensitive to side reactions in dipolar aprotic solvents.

Preparation and Polymerization of Macrocyclic Oligomers

Ring-opening polymerization reactions (Equation 1) constitute an important class of polymerization techniques. A number of commercial products are prepared via ringopening polymerization reactions, and the preparation of monomers, studies of catalysis and mechanism, and product development of many of these materials are active areas of academic and industrial research. Ring-opening polymerization chemistry has been extensively reviewed in several monographs, 1 and in many review articles.2 A wide variety of monomers have been utilized in ring-opening reactions; these polymerizations are commercially utilized for the preparation of polyamides, aliphatic polyesters, silicones, polyalkylenes (via ring-opening methathesis polymerizations), and epoxide thermosets. For this paper, discussion will be limited to three categories of ring-opening polymerization reactions: monomelic strained ring systems, which have high reaction exotherms, monomelic medium ring systems, which have moderate exotherms, and oligomeric large ring systems, which have little or no reaction exotherm.