625-34-3Relevant academic research and scientific papers
UV Photochemistry of Acetylacetaldehyde Trapped in Cryogenic Matrices
Coussan, S.,Ferré, N.,Rousselot-Pailley, P.,Sobanska, S.
, p. 4916 - 4928 (2020)
The broad band UV photochemistry of acetylacetaldehyde, the hybrid form between malonaldehyde and acetylacetone (the two other most simple molecules exhibiting an intramolecular proton transfer), trapped in four cryogenic matrices, neon, nitrogen, argon, and xenon, has been studied by IRTF spectroscopy. These experimental results have been supported by B3LYP/6-311G++(2d,2p) calculations in order to get S0 minima together with their harmonic frequencies. On those minima, we have also calculated their vibrationally resolved UV absorption spectra at the time-dependent DFT ωB97XD/6-311++G(2d,2p) level. After deposition, only the two chelated forms are observed while they isomerize upon UV irradiation toward nonchelated species. From UV irradiation effects we have identified several nonchelated isomers, capable, in turn, of isomerizing and fragmenting, even if this last phenomenon seems to be most unlikely due to cryogenic cages confinement. On the basis of these findings, we have attempted a first approach to the reaction path of electronic relaxation. It appeared that, as with acetylacetone, the path of electronic relaxation seems to involve triplet states.
Straightforward entry into 5-hydroxy-1-aminopyrrolines and the corresponding pyrroles from 1,2-diaza-1,3-butadienes
Attanasi, Orazio A.,De Crescentini, Lucia,Favi, Gianfranco,Filippone, Paolino,Mantellini, Fabio,Santeusanio, Stefania
, p. 8178 - 8181 (2002)
The synthesis of 5-hydroxy-1-aminopyrroline-3-carboxylic acid derivatives and 5-unsubstituted-1-aminopyrrole-3-carboxylic acid derivatives from 1,2-diaza-1,3-butadienes and aldehydes is presented. These domino reactions offer the advantage of executing multistep transformation without intermediate workup procedures. The stereoselectivity of ring closure to 5-hydroxy-1-aminopyrroline-3-carboxylic acid derivatives and phenyl transposition to 2,3-diphenyl-1-aminopyrrole-3-carboxylic acid derivatives are also studied.
Cassis and Green Tea: Spontaneous Release of Natural Aroma Compounds from β-Alkylthioalkanones
B?ttig, Sarah,Bochet, Christian G.,Egger, Timothy,Flachsmann, Felix,Gey, Olga
, (2021/10/19)
In depth headspace analysis of the slow degradation of β-alkylthioalkanones in ambient air led to the discovery of a novel δ-cleavage pathway, by which β-mercaptoketones are released. Since β-mercaptoketones are potent natural aroma compounds occurring in many fruits, herbs and flowers, the discovery of an enzyme-independent molecular precursor for this class of high-impact molecules is of practical importance. Moreover, the formation of β-diketones and aldehydes by concomitant oxidation at the α-sulfur-position enhances the versatility of this class of aroma precursors. A mechanistic model is proposed which suggests that the oxidative degradation occurs through a novel Pummerer-type rearrangement of initially formed persulfoxides.
Reaction of alkyl- and arylamines with 2-(hydroxyimino)-3-oxobutanal
Yarofeeva,Tsutsura,Frolenko,Semichenko,Kondrasenko,Suboch
, p. 1 - 5 (2017/03/16)
The condensation of 2-(hydroxyimino)-3-oxobutanal with primary aliphatic amines, cyclohexanamine, and amines containing an adamantane fragment afforded 4-(alkylamino)- and 4-(cyclohexylamino)-3- nitrosobut-3-en-2-ones. Analogous reaction with substituted anilines RC6H4NH2 (R = H, 4-Me, 4-OMe, 4-NH2, 4-Br, 4-I, 3-NO2) led to the formation of 4-aryl-3-hydroxyiminobutan-2-ones.
SUBSTITUTED PYRROLO[1,2-A]PYRIMIDINES AND THEIR USE IN THE TREATMENT OF MEDICAL DISORDERS
-
Paragraph 00547, (2016/06/28)
The invention provides substituted pyrrolo[l,2-a]pyrimi dines and related organic compounds, compositions containing such compounds, medical kits, and methods for using such compounds and compositions to treat medical disorders, e.g., Gaucher disease, Parkinson's disease, Lewy body disease, dementia, or multiple system atrophy, in a patient. Exemplary substituted pyrrolo[1,2-a]pyrimidines compounds described herein include substituted 2,4-dimethyl-N-phenylpyrrolo[l,2-a]pyrimidine-8-carboxamide compounds and variants thereof.
Thiamine pyrophosphate stimulates acetone activation by desulfococcus biacutus as monitored by a fluorogenic ATP analogue
Gutiérrez Acosta, Olga B.,Hardt, Norman,Hacker, Stephan M.,Strittmatter, Tobias,Schink, Bernhard,Marx, Andreas
, p. 1263 - 1266 (2014/07/08)
Acetone can be degraded by aerobic and anaerobic microorganisms. Studies with the strictly anaerobic sulfate-reducing bacterium Desulfococcus biacutus indicate that acetone degradation by these bacteria starts with an ATP-dependent carbonylation reaction leading to acetoacetaldehyde as the first reaction product. The reaction represents the second example of a carbonylation reaction in the biochemistry of strictly anaerobic bacteria, but the exact mechanism and dependence on cofactors are still unclear. Here, we use a novel fluorogenic ATP analogue to investigate its mechanism. We find that thiamine pyrophosphate is a cofactor of this ATP-dependent reaction. The products of ATP cleavage are AMP and pyrophosphate, providing first insights into the reaction mechanism by indicating that the reaction proceeds without intermediate formation of acetone enol phosphate.
Branching ratios for the reaction of selected carbonyl-containing peroxy radicals with hydroperoxy radicals
Hasson, Alam S.,Tyndall, Geoffrey S.,Orlando, John J.,Singh, Sukhdeep,Hernandez, Samuel Q.,Campbell, Sean,Ibarra, Yesenia
experimental part, p. 6264 - 6281 (2012/08/28)
An important chemical sink for organic peroxy radicals (RO2) in the troposphere is reaction with hydroperoxy radicals (HO2). Although this reaction is typically assumed to form hydroperoxides as the major products (R1a), acetyl peroxy radicals and acetonyl peroxy radicals have been shown to undergo other reactions (R1b) and (R1c) with substantial branching ratios: RO2 + HO2 → ROOH + O2 (R1a), RO 2 + HO2 → ROH + O3 (R1b), RO2 + HO2 → RO + OH + O2 (R1c). Theoretical work suggests that reactions (R1b) and (R1c) may be a general feature of acyl peroxy and α-carbonyl peroxy radicals. In this work, branching ratios for R1a-R1c were derived for six carbonyl-containing peroxy radicals: C2H 5C(O)O2, C3H7C(O)O2, CH3C(O)CH2O2, CH3C(O)CH(O 2)CH3, CH2ClCH(O2)C(O)CH 3, and CH2ClC(CH3)(O2)CHO. Branching ratios for reactions of Cl-atoms with butanal, butanone, methacrolein, and methyl vinyl ketone were also measured as a part of this work. Product yields were determined using a combination of long path Fourier transform infrared spectroscopy, high performance liquid chromatography with fluorescence detection, gas chromatography with flame ionization detection, and gas chromatography-mass spectrometry. The following branching ratios were determined: C2H5C(O)O2, YR1a = 0.35 ± 0.1, YR1b = 0.25 ± 0.1, and YR1c = 0.4 ± 0.1; C3H7C(O)O2, YR1a = 0.24 ± 0.15, YR1b = 0.29 ± 0.1, and YR1c = 0.47 ± 0.15; CH3C(O)CH2O2, Y R1a = 0.75 ± 0.13, YR1b = 0, and YR1c = 0.25 ± 0.13; CH3C(O)CH(O2)CH3, Y R1a = 0.42 ± 0.1, YR1b = 0, and YR1c = 0.58 ± 0.1; CH2ClC(CH3)(O2)CHO, Y R1a = 0.2 ± 0.2, YR1b = 0, and YR1c = 0.8 ± 0.2; and CH2ClCH(O2)C(O)CH3, YR1a = 0.2 ± 0.1, YR1b = 0, and YR1c = 0.8 ± 0.2. The results give insights into possible mechanisms for cycling of OH radicals in the atmosphere.
Modular synthesis of phenanthridine derivatives by oxidative cyclization of 2-isocyanobiphenyls with organoboron reagents
Tobisu, Mamoru,Koh, Keika,Furukawa, Takayuki,Chatani, Naoto
supporting information, p. 11363 - 11366 (2013/01/15)
Where HAS you been? A manganese-mediated annulation of 2-isocyanobiaryls with organoboronic acids is developed for the synthesis of a broad range of phenanthridine derivatives (see scheme). Mechanistic studies indicate that the reaction proceeds by the intramolecular homolytic aromatic substitution (HAS) of an imidoyl radical intermediate. Copyright
Stereoselective control in the Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents: Experimental investigation and theoretical rationalization
Qi, Hengzhen,Li, Xinyao,Xu, Jiaxi
supporting information; experimental part, p. 2702 - 2714 (2011/05/19)
The stereoselectivity of the Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents was investigated experimentally by determination of the product stereochemistry and theoretically via DFT calculations. The results indicate that imines preferentially attack the less sterically hindered exo-side of the ketenes to generate zwitterionic intermediates. Subsequently, for cyclic imines, the intermediates undergo a conrotatory ring closure directly to produce β-lactams, while for linear imines, the imine moiety of the intermediates isomerizes to more stable intermediates, which further undergo a conrotatory ring closure to afford trans-β-lactams. The steric hindrance and the isomerization, rather than the torquoelectronic effect, play crucial roles in controlling the stereoselectivity in the practical Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents, although the unaccessible borylketene with a powerful electron acceptor group controls the stereoselectivity torquoelectronically, in theory.
Expeditious synthesis of 2,3,6-trisubstituted 2 H -1,3-oxazin-4(3 H)-ones via the tertiary amine-induced reaction of 2-diazo-3-oxoalkanals and imines under mild conditions
Qi, Hengzhen,Zhang, Jiantao,Xu, Jiaxi
supporting information; experimental part, p. 887 - 894 (2011/05/05)
A series of 2,3,6-trisubstituted 2H-1,3-oxazin-4(3H)-one derivatives were conveniently synthesized in satisfactory to good yields by the reaction of imines with 2-diazo-3-oxoalkanals in the presence of a catalytic amount of a tertiary amine during several seconds under mild condition. Different bases and -diazo - dicarbonyl compounds were also evaluated and a reaction mechanism is proposed. Compared with the corresponding thermal- and photo-induced- reactions, the current method is a metal-free, mild, highly regioselective, and more efficient approach for the synthesis of 2H-1,3-oxazin-4(3H)-one derivatives. Georg Thieme Verlag Stuttgart - New York.
