83725-18-2Relevant academic research and scientific papers
Chemo-, Regio-, and stereoselective trifluoromethylation of styrenes via visible light-driven single-electron transfer (SET) and triplet-triplet energy transfer (TTET) processes
Lin, Qing-Yu,Xu, Xiu-Hua,Qing, Feng-Ling
, p. 10434 - 10446 (2015/02/19)
A process for tunable and chemo-, regio-, and stereoselective photocatalytic trifluoromethylation of styrenes was developed. Thermodynamically stable E-trifluoromethylated alkenes were prepared using Tognis reagent in the presence of Ru(bpy)3Cl2·6H2O under visible light irradiation, whereas less thermodynamically stable Z-trifluoromethylated alkenes were obtained by employing Umemotos reagent and photocatalyst Ir(ppy)3.
Studies on electronic effects in O-, N- and S-chelated ruthenium olefin-metathesis catalysts
Tzur, Eyal,Szadkowska, Anna,Ben-Asuly, Amos,Makal, Anna,Goldberg, Israel,Wozniak, Krzysztof,Grela, Karol,Lemcoff, N. Gabriel
experimental part, p. 8726 - 8737 (2010/10/19)
A short overview on the structural design of the Hoveyda-Grubbs-type ruthenium initiators chelated through oxygen, nitrogen or sulfur atoms is presented. Our aim was to compare and contrast O-, N- and S-chelated ruthenium complexes to better understand the impact of electron-withdrawing and -donating substituents on the geometry and activity of the ruthenium complexes and to gain further insight into the trans-cis isomerisation process of the S-chelated complexes. To evaluate the different effects of chelating heteroatoms and to probe electronic effects on sulfur- and nitrogen-chelated latent catalysts, we synthesised a series of novel complexes. These catalysts were compared against two well-known oxygen-chelated initiators and a sulfoxide-chelated complex. The structures of the new complexes have been determined by single-crystal X-ray diffraction and analysed to search for correlations between the structural features and activity. The replacement of the oxygen-chelating atom by a sulfur or nitrogen atom resulted in catalysts that were inert at room temperature for typical ring-closing metathesis (RCM) and cross-metathesis reactions and showed catalytic activity only at higher temperatures. Furthermore, one nitrogen-chelated initiator demonstrated thermo-switchable behaviour in RCM reactions, similar to its sulfur-chelated counterparts.
