25844-12-6Relevant articles and documents
Intramolecular C-O Insertion of a Germanium(II) Salicyl Alcoholate: A Combined Experimental and Theoretical Study
Kitschke, Philipp,Rüffer, Tobias,Korb, Marcus,Lang, Heinrich,Schneider, Wolfgang B.,Auer, Alexander A.,Mehring, Michael
, p. 5467 - 5479 (2015)
The synthesis of germanium(II) 2-tert-butyl-4-methyl-6-(oxidomethyl)phenolate (1) starting from Ge[N(SiMe3)2]2 and the corresponding salicyl alcohol is reported. Compound 1 undergoes an intramolecular oxidative insertion reaction of germanium into a C-O bond to result in a cyclic germanium(IV) tetraoxidogermocane (2). Addition of 3-tert-butyl-2-hydroxy-5-methylbenzyl alcohol to either compound 1 or 2 gave a spirocyclic monoorgano dioxagermine (3). The results of 1H NMR spectroscopic studies and DFT-D calculations are in agreement with the proposed reaction cascade in which the novel germylene 1 is first converted into the germocane 2 followed by reaction with 3-tert-butyl-2-hydroxy-5-methylbenzyl alcohol to finally provide compound 3. Addition of 4-(dimethylamino)pyridine to a solution of germylene 1 resulted in the formation of an air-stable monomeric 1:1 complex (4). The characterization of compounds 1-4 by single-crystal X-ray diffraction analysis, thermal analysis, and 1H NMR, 13C{1H} NMR, and ATR-FTIR spectroscopy is presented. Germylene 1 underwent an intramolecular oxidative insertion of Ge into a C-O bond in solution to give cyclic germocanes 2. Addition of 3-tert-butyl-2-hydroxy-5-methylbenzyl alcohol to 1 or 2 gave spirocyclic dioxagermine 3. 1H NMR analysis and DFT calculations concur with the proposed reaction cascade. Intermolecular stabilization of 1 upon addition of DMAP provided a stable monomeric 1:1 complex.
BRANCHED DIEPOXIDE COMPOUNDS FOR THE TREATMENT OF INFLAMMATORY DISORDERS
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Page/Page column 91, (2009/09/04)
The present invention provides certain diepoxide carbocyclic compounds wherein at least one carbocyclic ring carbon includes two non-epoxide substituents, and pharmaceutical compositions containing the same, for the treatment or prophylaxis of inflammator
Kinetic Studies of the Methanolysis Reaction of Chloromethylated Phenols
Stein, Guenter,Boehmer, Volker,Lotz, Werner,Kaemmerer, Hermann
, p. 231 - 241 (2007/10/02)
The solvolysis of 25 differently substituted chloromethylated phenols was studied kinetically in methanol at 25 deg C.A sharp decrease of the initial reaction rate with increasing concentrations of added acids can be explained by a very fast solvolysis of the phenolate anions in comparison with the undissociated compounds.The latter show strictly first order kinetics up to high conversions and the rate constants can be partly correlated with the Jaffe relation.Highly negative values for the reaction constants ρ=-5.4 and ρ=-6.2 for ortho- and para-chloromethylated compounds show, that the undissociated phenols react according to the SN1-mechanism.However, deviations are found for compounds with strongly electron attracting substituents, which may be partly caused by an intramolecular catalytic effect of the phenolic hydroxy group in the case of the ortho-isomers. - Keywords: Methanolysis, Chloromethylated Phenols, Anchimeric Assistance