An efficient access to the novel 5-(het)arylamino-1,2,3-triazole derivatives has been developed. The method is based on Buchwald–Hartwig cross-coupling reaction of 5-Amino or 5-Halo-1,2,3-triazoles with (het)aryl halides and amines, respectively. As result, it was found that palladium complex [(THP-Dipp)Pd(cinn)Cl] bearing expanded-ring N-heterocyclic carbene ligand is the most active catalyst for the process to afford the target molecules in high yields.
1 August 2009 in Russian Journal of Organic Chemistry
Reactions of carbonyl compounds of aliphatic, aromatic, and heteroaromatic series with dialkyl phosphites in the presence of DBN were studied under microwave irradiation.
“Green” thermally stable hardener was synthesized from a PET waste. The rigid molecular linear structure of the new hardener suggests that it will provide the polymer matrix with the necessary physical and mechanical characteristics. It also allows the expectation that cured matrix based on this hardener can provide increased toughness. New hardener was used as a curing agent for three epoxy resins—tetraglycidyl methylenedianiline (TGDMA, 111–117 EEW), diglycidylether of bisphenol A (DGEBA, 170-192 EEW) and solid epoxy resin (SER)—with a medium molecular weight (860–930 EEW) based on DGEBA. The mixtures were found to have the highest Tg for the DGEBA resin, and high of that for TGDMA and SER. According to the DMA analysis for two cured matrices, the hardener proved to be no worse than the standard ones, and made it possible to obtain cured matrices with excellent mechanical properties, which allows us to hope for further application of new hardener cured epoxy matrices in appropriate composite materials at high temperatures.
This paper describes an investigation of the catalytic activity of a series of N-heterocyclic palladium(II) complexes with a cinnamyl auxiliary ligand in telomerization of butadiene with methanol. The catalytic activity of the cinnamyl N-heterocyclic complexes was compared with that of PEPPSI type complexes.
Palladium catalyzed Heck-type intramolecular cyclization of N-(2-bromoaryl)pyridinium salts gives pyrido[1,2-a]indoles. A one-pot two-step procedure from pyrylium salts has been developed. The reaction is scalable and affords high product yields.