107-70-0Relevant articles and documents
Novel amine-catalysed hydroalkoxylation reactions of activated alkenes and alkynes
Murtagh, Julie E.,McCooey, Seamus H.,Connon, Stephen J.
, p. 227 - 229 (2005)
Substoichiometric loadings of DBU catalyse the efficient 1,4-addition of alcohols and non-nucleophilic amines such as pyrrole to activated alkenes; the application of this methodology in a one-pot synthesis of a natural product, and as a novel strategy for the synthesis of mono-protected 1,3-carbonyl compounds is reported.
LE CATION METHYLENECYCLOPROPYLE: ETUDE THEORIQUE. SOLVOLYSE DES HALOGENOCYCLOPROPENES ET DES HALOGENOMETHYLENE-CYCLOPROPANES
Arnaud, R.,Dussauge, A.,Faucher, H.,Subra, R.,Vidal, M.,Vincens, M.
, p. 315 - 326 (1984)
The solvolysis in acid solution of allylic halides and acetates of methylenecyclopropanes and cyclopropylmethanes does not lead to ring opening when there is an ethoxycarbonyl substituent on the ring methylene.Only the cyclopropenyl derivative is obtained.A study of the electronic structure and the geometry of the possible allylic cation intermediate has been carried out using the MNDO method.In addition, the influence of the substituents on the ring opening of this cation has been examined.It appears that the ring opening is disfavoured upon substitution of an alkyl group by alkoxymethyl on the ring methylene group.
Studies on the low-temp oxidation of coal containing organic sulfur and the corresponding model compounds
Zhang, Lanjun,Li, Zenghua,Li, Jinhu,Zhou, Yinbo,Yang, Yongliang,Tang, Yibo,McPhee, Derek J.
, p. 22241 - 22256 (2015)
This paper selects two typical compounds containing organic sulfur as model compounds. Then, by analyzing the chromatograms of gaseous low-temp oxidation products and GC/MS of the extractable matter of the oxidation residue, we summarizing the mechanism of low-temp sulfur model compound oxidation. The results show that between 30 °C to 80 °C, the interaction between diphenyl sulfide and oxygen is mainly one of physical adsorption. After 80 °C, chemical adsorption and chemical reactions begin. The main reaction mechanism in the low-temp oxidation of the model compound diphenyl sulfide is diphenyl sulfide generates diphenyl sulfoxide, and then this sulfoxide is further oxidized to diphenyl sulphone. A small amount of free radicals is generated in the process. The model compound cysteine behaves differently from diphenyl sulfide. The main reaction low-temp oxidation mechanism involves the thiol being oxidized into a disulphide and finally evolving to sulfonic acid, along with SO2 being released at 130 °C and also a small amount of free radicals. We also conducted an experiment on coal from Xingcheng using X-ray photoelectron spectroscopy (XPS). The results show that the major forms of organic sulfur in the original coal sample are thiophene and sulfone. Therefore, it can be inferred that there is none or little mercaptan and thiophenol in the original coal. After low-temp oxidation, the form of organic sulfur changes. The sulfide sulfur is oxidized to the sulfoxide, and then the sulfoxide is further oxidized to a sulfone, and these steps can be easily carried out under experimental conditions. What's more, the results illustrate that oxidation promotes sulfur element enrichment on the surface of coal.
Molecular design of organic superbases, azacalix[3](2,6)pyridines: Catalysts for 1,2-and 1,4-additions
Uchida, Natsuko,Kuwabara, Junpei,Taketoshi, Ayako,Kanbara, Takaki
, p. 10631 - 10637 (2013/02/22)
The molecular design, characteristics, and catalytic activity of macrocyclic amino compounds, azacalix[3](2,6)pyridine derivatives, were studied. The introduction of an electron-donating group on the pyridine moiety and bridging amino phenyl group enabled the enhancement of the basicity of azacalix[3](2,6)pyridine up to pKBH+ = 29.5 in CD3CN. These derivatives were shown to be efficient catalysts for 1,4-addition reactions of nitroalkanes or primary alcohols to α,β-unsaturated carbonyl compounds and 1,2-addition reactions of nitroalkanes to aromatic aldehydes.
Direct access to cumbersome aminated quaternary centers by hyperbaric aza-Michael additions
Rulev, Alexander Yu.,Azad, Saleha,Kotsuki, Hiyoshizo,Maddaluno, Jacques
experimental part, p. 6423 - 6429 (2011/02/24)
The aza-Michael addition of secondary amines to α, β or ββdisubstituted α, βunsaturated esters was efficiently achieved under high pressure (10-16 kbar) in protic solvents in the absence of any catalyst. The expected cumbersome β-aminoesters bearing a tertiary amine directly connected to a quaternary carbon atom could be isolated in fair to good yields. By using αβδγ-unsaturated esters (alkyl sorbate), the addition took place regioselectively in a 1,6 manner and afforded the β,γ -unsaturated δ-aminoesters. Copyright
A facile procedure for acetalization of aldehydes and ketones catalyzed by cerium(III) trifluoromethanesulfonate
Ono, Fumiaki,Inatomi, Yoshiko,Tada, Yuusuke,Mori, Masaki,Sato, Tsuneo
scheme or table, p. 96 - 97 (2009/11/30)
Aldehydes and ketones are readily protected in the presence of trialkyl orthoformate and a catalytic amount of cerium(III) trifluoromethanesulfonate under mild conditions to give the corresponding acetals in good to excellent yields. Due to the mild reaction conditions, this method is compatible with acid-sensitive substrates. Copyright
P(RNCH2CH2)3N: Efficient 1,4-addition catalysts
Kisanga, Philip B.,Ilankumaran, Palanichamy,Fetterly, Brandon M.,Verkade, John G.
, p. 3555 - 3560 (2007/10/03)
The 1,4-addition of primary alcohols, higher nitroalkanes, and a Schiff's base of an α-amino ester to α,β-unsaturated substrates produces the corresponding products in moderate to excellent yields when carried out at -63 to 70°C in the presence of catalytic amounts of the nonionic strong bases P(RNCH2CH2)3N (R = Me, i-Pr, i-Bu) in isobutyronitrile. Diastereoselectivity for the anti form of the product is high in the case of the Schiff's base in the absence of lithium ion. These catalysts are easily removed from the product by either column filtration through silica gel or via aqueous workup.
Synthesis and β-adrenergic activity of new completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives
Balsamo,Gentili,Lapucci,Macchia,Martinelli,Orlandini,Ferni,Pinza
, p. 759 - 766 (2007/10/02)
In a previous paper, it had been found that completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives showed a good β-blocking adrenergic activity directed prevalently towards β2-tracheal receptors. In an attempt to change the β-adrenergic properties of these compounds from antagonist to agonist, while still retaining the β2-selectivity, a series of new completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives were designed in which either a hydroxylic or a methoxylic group was present on the aliphatic portion linked to the oximic carbon. The synthesis of the new compounds and their β-adrenergic activity, evaluated by means of functional tests on isolated preparations, are described and discussed; the results obtained are then rationalised on the basis of their conformational and reactivity characteristics, determined by means of theoretical methods.
Crossed aldol-type reactions catalyzed by rhodium complexes
Sato, Susumu,Matsuda, Isamu,Izumi, Yusuke
, p. 223 - 238 (2007/10/02)
Crossed aldol-type reactions of enol trimethylsilyl ethers with aldehydes and ketones are smooth when carried out with a catalytic amount of a rhodium complex, Rh4(CO)12 or X (X=PF6 and ClO4; COD=cycloocta-1,5-diene, DPPB=1,4-bis(diphenylphosphino)butane), under neutral conditions.A suitable catalyst enables the isolation of three different types of aldol reaction product, β-trimethylsiloxy ketones, β-hydroxy ketones, and α,β-unsaturated ketones.Rh4(CO)12 and ClO4 also catalyze the reaction of enol trimethylsilyl ethers with acetals or ketals, whereas PF6 does not.When ClO4 is used as the catalyst, this type of aldol reaction is extended to the one-pot synthesis of trisubstituted furans from enol trimethylsilyl ether and α-trimethylsiloxy acetal.
ALDOL-TYPE REACTIONS BETWEEN TRIMETHYLSILYL ENOL ETHERS AND ACETALS WITH THE AID OF RHODIUM COMPLEX
Sato, Susumu,Matsuda, Isamu,Izum, Yusuke
, p. 6657 - 6660 (2007/10/02)
Aldol type reactions of trimethylsilyl enol ethers with acetals, ketals and orthoesters are successfully performed with the aid of a catalytic amount of rhodium complex Rh4(CO)12 or (Rh(COD)(DPPB))(1+)*ClO4(1-), under neutral conditions.
