954-07-4Relevant articles and documents
Reactivity of Stable Rotamers. XXXV. Diazotization of 2-(1,4-Dimethyl-9-triptycyl)-2-methylpropylamine Rotamers
Oki, Michinori,Taguchi, Yasushi,Miyasaka, Tsutomu,kitano, Mika,Toyota, Shinji,et al.
, p. 1485 - 1496 (1995)
The title amine rotamers were prepared from the corresponding carboxylic acids and were diazotized with isopentyl nitrite in the presence of acetic acid in benzene.The ap rotamer affords, as main products, olefins that are derived by deprotonation after rearrangement of the intervening carbocation and small amounts each of the corresponding acetate and a cyclized product, both of which are derived from the unrearranged cation.By contrast, the olefins a minor products and a cyclized product, which is formally derived by insertion of the intervening cation to a C-H bond of the 1-methyl group before rearrangement, is main in the case of the sc isomer.This cyclic product was synthesized independently.The yield of the corresponding acetate is increased to a considerable extent in the case of the sc relative to the ap.These results in the reaction of the sc are discussed in terms of stabilization of the intervening cation by the C-H bond.
Experimental and theoretical study of photoenolization mechanism for 1-methylanthraquinone
Gritsan, Nina P.,Khmelinski, Igor V.,Usov, Oleg M.
, p. 9615 - 9620 (1991)
Photoenolization of 1-methylanthraquinone (AQ) and its deuterated analogue (AQ-d6) has been studied by laser flash photolysis over a wide temperature range (120-340 K). Phototransfer of a H (or D) atom has been found to occur in both the singlet and triplet nπ* states. The temperature dependence of the efficiency of the phototransfer of H and D atoms in the 1nπ* state has been analyzed. Piperylene quenching of AQ and AQ-d6 triplet excited states has been studied. The rate constants of H- and D-atom phototransfer at room temperature have been estimated to be ca. 3 × 1010 s-1 and ca. 1010 s-1, respectively. Quantum-chemical calculations of potential energy surfaces and of electronic and geometrical structures of key intermediates have been performed by using the AMI technique. A triplet σ,π-biradical has been found to be the intermediate preceding the formation of 9-hydroxy-1,10-anthraquinone-1-methide (AQM). It has been revealed that thermal transformation of the enol AQM to the initial quinone AQ can occur as an intramolecular process via reverse transfer of a H atom, or as a second-order reaction. The latter appears to involve the transfer of two H (or D) atoms in a collisional complex of two AQM molecules. The dependence of the rate constants of the intramolecular thermal transfer of H and D atoms on temperature and solvent nature has been analyzed.
Full Cleavage of C≡C Bond in Electron-Deficient Alkynes via Reaction with Ethylenediamine
Vasilevsky, Sergei F.,Davydova, Maria P.,Mamatyuk, Victor I.,Tsvetkov, Nikolay,Hughes, Audrey,Baranov, Denis S.,Alabugin, Igor V.
, p. 421 - 429 (2017/04/07)
Reaction of 1,2-diaminioethane (ethylenediamine) with electron-deficient alkynes leads to full scission of the C≡C bond even in the absence of a keto group directly attached to the alkyne. This process involves oxidation of one of the alkyne carbons into C2 of a 2-R-4,5-dihydroimidazole with the concomitant reduction of the other carbon to a methyl group. The sequence of Sonogashira coupling with the ethylenediamine-mediated fragmentation described in this work can be used for selective formal substitution of halogen in aryl halides by a methyl group or a 4,5-dihydroimidazol-2-yl moiety.
Photoproducts of carminic acid formed by a composite from Manihot dulcis waste
Antonio-Cisneros, Cynthia M.,Dvila-Jimnez, Martn M.,Elizalde-Gonzlez, Mara P.,Garca-Daz, Esmeralda
, p. 725 - 732 (2015/01/09)
Carbon-TiO2 composites were obtained from carbonised Manihot dulcis waste and TiO2 using glycerol as an additive and thermally treating the composites at 800 °C. Furthermore, carbon was obtained from manihot to study the adsorption,
