25844-12-6Relevant academic research and scientific papers
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.
Selective ring opening of 4H-1,3,2-benzodioxasiline twin monomers
Kempe, Patrick,Loeschner, Tina,Adner, David,Spange, Stefan
experimental part, p. 2735 - 2739 (2012/01/11)
4H-1,3,2-Benzodioxasilines represent a class of monomers, which are suitable for the recently developed concept of twin polymerization. Relating to the prediction of quantum chemical calculations we are now able to confirm the results for the first step o
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
Stabilization of reactive aldehydes by complexation with methylaluminum bis(2,6-diphenylphenoxide) and their synthetic application
Maruoka, Keiji,Concepcion, Arnel B.,Murase, Noriaki,Oishi, Masataka,Hirayama, Naoki,Yamamoto, Hisashi
, p. 3943 - 3949 (2007/10/02)
Reactive aldehydes such as formaldehyde and α-chloro aldehydes can be successfully generated by treatment of readily available trioxane and α-chloro aldehyde trimers, respectively, with methylaluminum bis(2,6-diphenylphenoxide) (MAPH), and stabilized as their 1:1 coordination complexes with MAPH. The resulting CH2=O·MAPH complex reacts with a variety of olefins to furnish ene-reaction products with excellent regio- and stereoselectivities. In addition, this complex as well as α-chloro aldehyde-M APH complexes can be utilized as a stable source of gaseous formaldehyde and reactive α-chloro aldehydes, respectively, for the nucleophilic addition of various carbanions (organometallics, enolates, etc.). Formation of reactive aldehyde-MAPH complexes is firmly confirmed by 1H NMR spectroscopy. A space-filling model of aldehyde-M APH complexes implies that formaldehyde and α-chloro aldehydes coordinated with MAPH may be electronically stabilized by two parallel phenyl groups of aluminum ligands.
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
