Tao Ding

Copper-Catalyzed One-Pot Synthesis of 1,2,4-Triazoles from Nitriles and Hydroxylamine

A simple and efficient copper-catalyzed one-pot synthesis of substituted 1,2,4-triazoles through reactions of two nitriles with hydroxylamine has been developed. The protocol uses simple and readily available nitriles and hydroxylamine hydrochloride as the starting materials and inexpensive Cu(OAc)2 as the catalyst, and the corresponding 1,2,4-triazole derivatives are obtained in moderate to good yields. The reactions include sequential intermolecular addition of hydroxylamine to one nitrile to provide amidoxime, copper-catalyzed treatment of the amidoxime with another nitrile, and intramolecular dehydration/cyclization. This finding provides a new and useful strategy for synthesis of 1,2,4-triazole derivatives.

Base-mediated one-pot synthesis of 1,2,4-oxadiazoles from nitriles, aldehydes and hydroxylamine hydrochloride without addition of extra oxidant

A simple base-mediated one-pot synthesis of 3,5-disubstituted 1,2,4-oxadiazoles from nitriles, aldehydes and hydroxylamine hydrochloride has been developed, in which the aldehydes act as both substrates and oxidants. The reactions include three sequential procedures: base-promoted intermolecular addition of hydroxylamine to nitrile to lead to amidoxime, treatment of the amidoxime with an aldehyde to form 4,5-dihydro-1,2,4-oxadiazole, and oxidization of the 4,5-dihydro-1,2,4-oxadiazole by using another aldehyde to afford 1,2,4-oxadiazole. This method represents a direct and simple protocol for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles.

Base-mediated synthesis of unsymmetrical 1,3,5-triazin-2-amines via three-component reaction of imidates, guanidines and amides or aldehydes

A simple and efficient method for the base-mediated synthesis of unsymmetrical 1,3,5-triazin-2-amines has been developed. The protocol uses readily available imidates, guanidines, and amides or aldehydes as the starting materials, cesium carbonate as the base, no catalyst or additive is required, and the three-component reaction provides diverse 1,3,5-triazin-2-amines in moderate to good yields with tolerance of wide functional groups.

Living Radical Polymerization of Methyl Methacrylate Mediated by Tris-(4-Acetyphenyl)Methane

Pseudo-living radical polymerization and reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) were reported, utilizing tris-(4-acetyphenyl) methane (TAcPM) as the thermal iniferter and initiator, respectively. The polymerization of MMA using TAcPM as thermal iniferter possesses pseudo-living characteristics: Mn increases with conversion in a certain range, and the resulted polymer can be used as the macro-initiator for chain extension. The RATRP using TAcPM as the initiator shows linear kinetic plot, linear increase of Mn with conversion and narrow polydispersity indice (PDI) of the resultant polymers.

Synthesis and Characterization of Caged Phosphate Microparticles Coated with Melamine Resin Based on Composite Properties of Materials

In order to develop efficient “three in one” intumesent flame retardants, a novel caged bicyclic phosphate, tris(1-oxo-2,6,7-trioxa-1-phosphorbicyclo[2.2.2]octane methylene-4)phosphate (trimer) as the core material was encapsulated by melamine resin and etherified melamine resin as nitrogen resource respectively via in situ polymerization. The two microencapsulations were characterized by SEM, XPS and thermal gravimetric analysis. When they were used as intumesent flame retardant in epoxy they all exhibit good properties. With 20wt% loading amount the flame-retarded epoxy all can pass UL94 V-0 rating.