In the present work a novel improved and convenient procedure for the synthesis of oxazoles has been developed. Acetamide, instead of ammonium acetate, was used to react with phenacyl benzoates in boiling xylene in the presence of BF3/Et2O as the catalyst. According to this new synthetic route, nine oxazole compounds were readily prepared as single products in reasonably high yields. On the basis of the experimental results, a plausible mechanism of this reaction is proposed. Copyright

The synthesis, by the Suzuki coupling reaction, of a novel soluble blue light emitting polymer, poly{(9,9-dihexyl-2,7-fluorene-alt-co-[2,5-bis(decyloxy)-1,4-phenylene]}(PDHFDDOP) is reported. PDHFDDOP exhibits photoluminescence (PL quantum efficiency of 40% in neat films) and electroluminescence (EL) with deep blue emission.

A new series of p-n diblock conjugated copolymers consisting of alternate 1,4-bis- (oxadiazolyl)-2,5-dialkyloxybenzene and oligothiophenes with one to three thiophene rings (P1-P3) have been synthesized. The polymers have well-defined structures and exhibit good thermal stability with the onset decomposition temperatures in nitrogen at around 300℃. The glass transition temperature (Tg) of the polymers decreases with increasing the length of oligothiophene blocks. Both the absorption spectra and photoluminescence spectra shift to longer wavelength with increase in the length of oligothiophene blocks. The emissive color of the polymers could be tuned from blue to green to orange just by increasing the number of thiophene rings in the oilgothiophene blocks from one to three. No obvious change in reduction potential is found for the polymers with variation in the length of oligothiophene blocks. The reduction potential E1/2 of the polymers is measured by cyclic voltammetry to be around -1.7V vs SCE, comparable to those of poly(cyanoterephthalyidene) (CN-PPV) and other good electron-transporting materials. The oxidation potential of the polymers can be reduced remarkably by increasing the length of oligothiophene blocks. The oxidation potential E1/2 of P3 is measured to be 1.25V with the onset potential at 1.0V vs SCE. These values are comparable to those of some hole-injection favorable electroluminescent polymers. The results prove that the p-n diblock structure may be a promising molecular design for synthetically tuning the HOMO and LUMO of conjugated polymers.

A new series of conjugated polymers constituted of 3-alkylthiophenes and 1,4-di(1,3,4-oxadiazolyl)phenylene are synthesized through precursor polymers of polyhydrazides. The solubility of the precursor polymers and the corresponding target polymers is improved by increasing the length of side chains on thiophene rings, which results in a higher degree of the conversion from the precursors to the final polymers and thus results in longer effective conjugated length in the polymers bearing longer side chains. The thermal stability and electrochemical properties of the polymers are studied. The polymers emit blue light under the irradiation of UV light in their film states. The relative fluorescence yield in solutions increases with the increase in length of side chains on thiophene rings in the polymers and reaches up to 79% for the polymer bearing octyl side chains. The possibility of polymers being used as electroluminescent material in polymer light-emitting diodes (PLEDs) is demonstrated by the successful fabrication of a single-layer device of indium tin oxide (ITO)/polymer/Ca, which emits visible blue light above 8 V of forward bias.

Synthesis of the key intermediate (5) of Antillatoxin (1) is presented. The synthesis is based on the indium-rnediated allylation of 2,4,6,6-tetramethyl-2,4-heptadienal (3) and methyl (Z)-2- (bromomethyl)-2-butenoate (4) in saturated ammonium chloride catalyzed by lanthanide triflate which afforded the corresponding product 2 in good yield and high syn selectivity.