64130-73-0Relevant academic research and scientific papers
Synthesis of N-aryloxy-β-diketiminate ligands and coordination to zirconium, ytterbium, thorium, and uranium
Dulong, Florian,Thuery, Pierre,Ephritikhine, Michel,Cantat, Thibault
, p. 1328 - 1340 (2013/05/09)
Two examples of N-aryloxy-β-diketiminate dianions (11a,b) have been synthesized on a multigram scale, in four steps, from commercially available chemicals. The synthetic scheme relies on the sequential addition of 2,6-diisopropylaniline and 2-amino-4-tert-butylphenol (1a) (or 2-amino-4,6-di-tert-butylphenol (1b)) to acetylacetone, using Et 3OBF4 as an activation reagent. Both the nature of the activation reagent and the order of addition of the primary amines have a major impact on the outcome of the reaction, and acid catalysts (such as sulfuric acid or p-toluenesulfonic acid) lead to decomposition of the β-diketiminate backbone via formation of a benzoxazole derivative (3a,b). Using dianions 11a,b, mono- and bis(N-aryloxy-β-diketiminate) complexes of zirconium(IV), ytterbium(III), thorium(IV), and uranium(IV) have been synthesized (12-18), by salt metathesis reactions, and characterized by a combination of 1H/13C NMR spectroscopy, elemental analysis, and X-ray crystallography. The two ligands differ in their steric bulk and exhibit different coordination behaviors, which were rationalized on the basis of geometric considerations.
Highly Lipophilic Benzoxazoles with Potential Antibacterial Activity
Vinsova, Jarmila,Horak, Vaclav,Buchta, Vladimir,Kaustova, Jarmila
, p. 760 - 770 (2007/10/03)
A series of lipophilic 2-substituted 5,7-di-tert-butylbenzoxazoles was prepared in average yields by the reaction of 3,5-di-tert-butyl-1,2-benzoquinone with amino acids and dipeptides bearing N-terminal glycine. Dipeptides having other N-terminal amino acids undergo oxidative deamination. 5,7-Di-tert-butylbenzoxazoles have shown activity against Mycobacterium tuberculosis and some nontuberculous strains where isoniazid has been inactive. Antifungal activity was mediocre.
Reactions of Phenols with Thianthrene Cation Radical
Shin, Seung-Rim,Shine, Henry J.
, p. 2706 - 2710 (2007/10/02)
The phenols 2-R1-6-R2-phenol 1a-g in which R1 = R2 = tert-butyl, methyl, isopropyl, Cl, Br, F, and H reacted with thianthrene cation radical perchlorate (TH+ClO4-) to give 5-(4-hydroxyaryl)thianthreniumyl perchlorates 2a-g in good yield. o-Allylphenol (1i) behaved similarly. o-tert-Butylphenol (1h) gave both 5-(3-tert-butyl-4-hydroxyphenyl)thianthreniumyl perchlorate (2h) and a quinonoidal perchlorate (3), namely, 5-(3-thianthreniumyl-5-tert-butyl-6-oxo-2,4-cyclohexadien-1-ylidene)-5,5-dihydrothianthrene perchlorate.The 2,6-di-tert-butyl-4-R3-phenols 4a-c, R3 = tert-butyl, methoxy, and methyl, reacted with Th+ClO4- in nitrile solvents (RCN) to give 2-R-5-R3-7-tert-butylbenzoxazoles 5a-e.The tert-butyl group that was displaced by RCN in forming 5 was converted into t-BuNHCOR (8), tert-butyl alcohol, and isobutene.In contrast, 2-tert-butyl-4,6-dimethylphenol (9) gave, in CH3CN, 4-tert-butyl-2,5,7-trimethylbenzoxazole (11), that is, with migration of the displaced tert-butyl group.The reactions of 4-tert-butylphenol (14) and 2,4-di-tert-butylphenol (17) are also described.
