136197-65-4Relevant academic research and scientific papers
Hydrolysis of isobutylaluminum aryloxides studied by 1H NMR and quantum chemical methods
Faingol’d,Zharkov,Bravaya,Chernyak
, p. 1958 - 1965 (2017/04/03)
The results of 1H NMR and quantum chemical studies of hydrolysis of isobutylaluminum aryloxides are presented. According to the data of 1H NMR spectroscopy, the hydrolysis of monomeric diisobutylaluminum aryloxides (2,6-Bu2 t—C6H3O)AlBu2 i and (2,6-Bu2 t,4-Me—C6H2O)AlBu2 i occurs selectively at the Al—OAr bond to form the corresponding sterically bulky phenol and polyisobutylaluminoxane. At the molar ratios Al: H2O = 2, the formed sterically bulky phenol reacts slowly with diisobutylaluminum monoaryloxide to form isobutylaluminum diaryloxide. Dimeric aryloxide [(2-But—C6H4O)AlBu2 i]2 is not hydrolyzed under similar conditions. The quantum chemical calculations confirmed the experimental results: the hydrolysis at the Al—OAr bond has a lower energy barrier than that at the Al—C bond because of the formation of HH2O…OO?Ar hydrogen bonds.
Synthesis and properties of homogeneous models of the Re2O7/Al2O3 metathesis catalyst
Commereuc,Doledec
, p. 125 - 140 (2008/10/08)
Soluble complexes, including aluminum coordinated with a perrhenate and a 4-substituted-2-6-di-tert-butylphenoxy ligand or a CH2- or S-ortho bridged-4,4'-di-tert-butyldiphenoxy ligand, were synthesized and characterized. The reaction of (ArO)2Al-Cl with AgReO4 resulted in new complexes (ArO)2Al-OReO3 (A), which showed a low activity in the metathesis of 2-pentene. Complexes (ArO)2Al-R (R = isobutyl, ethyl) reacted with Re2O7 in tetrahydrofuran or dioxane, generating type B complexes including oligomeric linkages such as O3Re-[Al(OAr)-O]2-ReO3. Some of these complexes, unstable even under an argon atmosphere, were identified after stabilization with a Lewis base like quinuclidine or bipyridine. Before their stabilization, they exhibited a rather high activity in the metathesis of 2-pentene, with turnover frequency of 100/min, and functional olefins (diallylether, diallylsulfide). Upon reaction with (ArO)2Al-R in an ether solvent, A complexes might be converted into B complexes. The high activity of B complexes was associated with the presence of Al-O-Al linkages that are known to induce a powerful bidendate Lewis acidity.
