107820-27-9Relevant articles and documents
Synthesis, characterization, and catalytic evaluation of ruthenium-diphosphine complexes bearing xanthate ligands
Zain Aldin, Mohammed,Maho, Anthony,Zaragoza, Guillermo,Demonceau, Albert,Delaude, Lionel
, p. 13926 - 13938 (2018)
The reaction of [RuCl2(p-cymene)]2 with potassium O-ethylxanthate and a set of nine representative Ph2P-X-PPh2 bidentate phosphines (dppm, dppe, dppp, dppb, dpppe, dppen, dppbz, dppf, and DPEphos) afforded monometallic [Ru(S2COEt)2(diphos)] chelates 1-9 in 62-96% yield. All the products were fully characterized by using various analytical techniques and their molecular structures were determined by X-ray crystallography. They featured a highly distorted octahedral geometry with a S-Ru-S bite angle close to 72° and P-Ru-P angles ranging between 73° and 103°. Bond lengths and IR stretching frequencies recorded for the anionic xanthate ligands strongly suggested a significant contribution of the EtO+CS22- resonance form. 1H NMR and XRD analyses showed that the methylene protons of the ethyl groups were diastereotopic due to a strong locking of their conformation by a neighboring phenyl ring. On cyclic voltammetry, quasi-reversible waves were observed for the Ru2+/Ru3+ redox couples with E1/2 values ranging between 0.65 and 0.80 V vs. Ag/AgCl. The activity of chelates 1-9 was probed in three catalytic processes, viz., the synthesis of vinyl esters from benzoic acid and 1-hexyne, the cyclopropanation of styrene with ethyl diazoacetate, and the atom transfer radical addition of carbon tetrachloride and methyl methacrylate. In the first case, 31P NMR analysis of the reaction mixtures showed that the starting complexes remained mostly unaltered despite the harsh thermal treatment that was applied to them. In the second case, monitoring the rate of nitrogen evolution revealed that all the catalysts under investigation behaved similarly and were rather slow initiators. In the third case, [Ru(S2COEt)2(dppm)] was singled out as a very active and selective catalyst already at 140 °C, whereas most of the other complexes resisted degradation up to 160 °C and were only moderately active. Altogether, these results were in line with the high stability displayed by [Ru(S2COEt)2(diphos)] chelates 1-9.
Addition of carboxylic acids to alkynes catalysed by ruthenium complexes
Rotem, Michal,Shvo, Youval
, p. 189 - 204 (1993)
The addition of carboxylic acids to alkynes has been found to be catalyzed by Ru3(CO)12 as well as by dimeric ruthenium carboxylate complexes of general structure 2.The reaction yields vinyl esters.It was found to be general with respect
Cationic ruthenium complex of the formula [RuCl(2,6-diacetylpyridine)(PPh3)2]BArF and its catalytic activity in the formation of enol esters
Stark, Matthew J.,Tang, Douglas T.,Rath, Nigam P.,Bauer, Eike B.
, p. 873 - 877 (2018)
A new ruthenium 2,6-diacetylpyridine complex was synthesized and applied in the atom-economic synthesis of enol esters through Markovnikov-directed addition of carboxylic acids to terminal alkynes. The ruthenium complex [RuCl(dap)(PPh3)2]+BArF? was synthesized from [RuCl2(PPh3)2] and the corresponding ligand 2,6-diacetylpyridine (dap). The complex was characterized structurally. The new ruthenium complex was utilized under ambient conditions as a catalyst in the Markovnikov addition of carboxylic acids to terminal alkynes to afford the corresponding enol esters in 93% to 52% isolated yields (85 °C, 16 h reaction time, 1 mol% catalyst loading).
General Synthesis of (Z)-Alk-1-en-1-yl Esters via Ruthenium-Catalyzed anti-Markovnikov trans-Addition of Carboxylic Acids to terminal Alkynes
Doucet, Henri,Martin-Vaca, Blanca,Bruneau, Christian,Dixneuf, Pierre H.
, p. 7247 - 7255 (1995)
The direct addition of carboxylic acids to terminal alkynes in the presence of catalytic amounts of (bis(diphenylphosphino)alkane)Ru(η3-methallyl)2 complexes provides a novel selective route to (Z)-alk-1-en-1-yl esters.This reaction involves an
Synthesis of ruthenium–dithiocarbamate chelates bearing diphosphine ligands and their use as latent initiators for atom transfer radical additions
Aldin, Mohammed Zain,Delaude, Lionel,Zaragoza, Guillermo
supporting information, (2021/08/03)
Nine representative [Ru(S2CNEt2)2(diphos)] complexes were prepared in almost quantitative yields (91–97%) from [RuCl2(p-cymene)]2, sodium diethyldithiocarbamate trihydrate, and a diphosphine (dppm, dppe, dppp, dppb, dpppe, dppen, dppbz, dppf, or DPEphos), using a novel, straightforward, one-pot procedure. The recourse to a monomodal microwave reactor was instrumental in reaching the thermodynamic equilibria favoring the targeted monometallic trichelates. All the products were fully characterized by using various analytical techniques and the molecular structures of seven of them were determined by X-ray crystallography. NMR, XRD, and IR spectroscopies evidenced a significant contribution of the thioureide resonance form Et2N+=CS22– to the electronic structure of the 1,1-dithiolate ligand. MS/MS spectrometry showed the formation of phosphine-free [Ru(S2CNEt2)2]+ cations in the gas phase, except when starting from [Ru(S2CNEt2)2(dppbz)]. The activity of the nine complexes was probed in three different catalytic processes, viz., the cyclopropanation of styrene with ethyl diazoacetate, the synthesis of vinyl esters from benzoic acid and 1-hexyne, and the atom transfer radical addition (ATRA) of carbon tetrachloride and methyl methacrylate. In the first two reactions, the saturated trichelates were poorly efficient. This was most likely due to their high stability, which prevented the formation of coordinatively unsaturated species. Contrastingly, with a turnover number of 2000 and an initial turnover frequency of 2080 h–1 for a 0.05 mol% catalyst loading, the [Ru(S2CNEt2)2(dppm)] complex emerged as a very robust, latent ATRA initiator, whose activity matched or outperformed those displayed by the most efficient ruthenium catalysts described so far.
Catalytic activity assessment of [RuCl2 (p-cymene) (PTA)] in the synthesis of enol esters
Musengimana, Eric,Fatakanwa, Claver
, p. 253 - 259 (2016/01/09)
The addition of carboxylic acids onto 1-hexyne was catalyzed by [RuCl2 (p-cymene) (PTA)] complex to give enol esters. Accordingly, the Markovnikov addition-type product was selectively obtained. The microwave-assisted reactions at 160 °C confir
