112399-08-3Relevant academic research and scientific papers
SNS-Ligands for Ru-Catalyzed Homogeneous Hydrogenation and Dehydrogenation Reactions
Sch?rgenhumer, Johannes,Zimmermann, Axel,Waser, Mario
supporting information, p. 862 - 870 (2018/06/18)
A detailed study of literature-known and novel S-containing pincer-type ligands for ruthenium-catalyzed homogeneous hydrogenation and dehydrogenation reactions was carried out. The scope and limitations of these catalysts were carefully investigated, and it was shown that simple bench-stable SNS-Ru complexes can be used to facilitate the hydrogenation of a variety of different substrates at a maximum H2 pressure of 20 bar under operationally simple, easy to scale up, glovebox-free conditions by using starting materials and reagents that do not require any special purification prior to use. It was also shown that such complexes can be used to catalyze the dehydrogenative coupling of alcohols and amines to get amides as well as for the dehydrogenative dimerization of alcohols to esters.
Synthesis of N,P-, S,P-, P,P- and S,P,S-ligands using reactions of cyclopalladated complexes with KPPh2
Korte, Nicholas J.,Stepanova, Valeria A.,Smoliakova, Irina P.
, p. 356 - 362 (2013/10/01)
Readily available air- and moisture-stable dimeric chloro-bridged CN-, CS- and CP-cyclopalladated complexes with the (sp2)C-Pd bond react with 4.5 equiv. of KPPh2 in THF to give the corresponding P,N-, P,S- and P,P-bidentate ligands
An experimental study on the effect of substituents on aromatic-aromatic interactions in dithia[3,3]-metaparacyclophanes
Xia, Jian Long,Liu, Sheng Hua,Cozzi, Franco,Mancinelli, Michele,Mazzanti, Andrea
supporting information; experimental part, p. 3611 - 3620 (2012/05/04)
Simple model systems based on the 2,11-dithia[3,3]-metaparacyclophane skeleton were synthesized to study the effects of substituents on the intramolecular aromatic-aromatic interactions between benzene rings. X-ray crystallography established that, in their more stable conformations, these metaparacyclophanes featured partially overlapping aromatic rings (interplanar distances of about 3.5 A), with the planes of the aromatic systems arranged in a slightly tilted disposition (interplanar angles in the range 5-19°). Calculations showed that these derivatives underwent topomerization by flipping of the meta-substituted ring over the para-substituted one, a process in which the two rings adopted a continuum of edge-to-face dispositions, including an orthogonal one, which were less stable than the starting face-to-face arrangement. The energy barriers to the isomerization process were experimentally determined by variable-temperature NMR spectroscopy, by using an internal temperature standard to assess even minor differences in energy (relative experimental error: (±0.1 kJ mol-1). The variation in the barriers as a function of the different substituents on the interacting ring was small and apparently unrelated to the effect of the substituents on the polarity of the π-systems. An explanation based on the charge-penetration effect seemed more-suitable to rationalize the observed trends in the barriers. Copyright
Reactions of Cyclopalladated Compounds. Part 21. Various Examples of Sulphur-assisted Intramolecular Palladation of Aryl and Alkyl Groups
Dupont, Jairton,Beydoun, Nohma,Pfeffer, Michel
, p. 1715 - 1720 (2007/10/02)
The cyclopalladation reactions of several sulphur-containing ligands have been investigated.The thioethers benzyl methyl sulphide, methyl naphthyl sulphide, 2,6-dimethylphenyl methyl sulphide, and neopentyl sulphide have been metallated by palladium acetate in acetic acid at either aryl or alkyl carbon atoms to afford, after reaction with lithium chloride in acetone, dimeric chloride-bridged cyclopalladated complexes in moderate (22percent) to good (81percent) yields.In these products each metal is part of a five-membered ring.The same reaction with 2-biphenyl methyl sulphide afforded a dimeric complex containing a six-membered cyclopalladated ring through palladation of the ortho position of the biphenyl group. 4,4'-Dimethoxythiobenzophenone and N,N,N',N'-tetramethyl-thiourea have been palladated by using a ligand-exchange reaction with 2> in the presence of stoicheiometric amounts of trifluoroacetic acid.This afforded good yields of dimeric palladocyclic complexes through the metallation of a carbon ortho to the thioketone, or of a methyl group of the thiourea, respectively.With 1,3-bis(methylthiomethyl)benzene this latter reaction, by metallation on the 2 position of the aryl ring, afforded excellent yields of a monomeric compound in which both sulphur atoms are co-ordinated to the palladium centre.
