1421704-98-4Relevant academic research and scientific papers
Catalytic Properties of Chromium Complexes Based on 1,2-Bis(diphenylphosphino)benzene in the Ethylene Oligomerization Reaction
Cheredilin,Sheloumov,Senin,Kozlova,Afanas’ev,Bespalova
, p. S72 - S87 (2020/01/23)
Abstract: The activity of the catalyst systems of a number of diphosphine ligands and chromium complexes based on 1,2-bis(diphenylphosphino)benzene in the ethylene oligomerization reaction has been studied. Structural modifications of diphosphine ligands have been performed to create selective catalyst systems for ethylene oligomerization. It has been shown that the introduction of ortho-functional groups into one of the phenyl substituents at the phosphorus atom in diphosphine ligands makes it possible to carry out the process of ethylene oligomerization to 1-hexene with the selectivity of 90 wt % and above. One of the complexes (chromium complex 15) with a functionalized diphosphine ligand has been characterized by X-ray structure analysis. The influence of the change in the amount of the activator and its type on the activity of the catalyst systems has been studied. It has been shown that the replacement of some organoaluminum activator, methylaluminoxane, by trimethylaluminum does not decrease the productivity and selectivity of the catalyst systems based on diphosphine chromium complexes.
Ditopic ligands featuring [P,S], [P,P] or [P,B] chelating pockets housed on a protected o-hydroquinone core
Chuong, Rose,Luck, Kyle A.,Luck, Rudy L.,Nguyen, Lillian P.,Phan, Diane,Pignotti, Louis R.,Urnezius, Eugenijus,Valente, Edward J.
, p. 45 - 50 (2013/03/13)
1,2-Dibromo-4,5-dimethoxybenzene was explored as a platform for the buildup of ditopic ligands. Low temperature reactions with n-butyllithium followed by quenches with various electrophiles led to the syntheses (2-bromo-4,5- dimethoxyphenyl)diphenylphosphine (1), (4,5-dimethoxy-2-(methylthio)phenyl) diphenylphosphine (2), 1,2-bis(diphenylphosphino)-4,5-dimethoxybenzene (3), and (2-(dicyclohexylboryl)-4,5-dimethoxyphenyl)diphenylphosphine (4). Oxidation of 3 produced 1,2-bis(diphenylphosphoryl)-4,5-dimethoxybenzene (5). All compounds were characterized by multinuclear (1H/13C/ 31P{1H}) NMR spectroscopy and by high resolution mass spectrometry. In addition, single crystal X-ray diffraction characterizations of 1, 3, 4, and 5 were also carried out. Reactivity of o-phosphinophenylborane 4 toward molecular hydrogen was also probed.
