- Aerobic oxidation of propargyl alcohol: A convenient method for the synthesis of propiolaldehyde
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Propiolaldehyde was prepared by the oxidation of propargyl alcohol using molecular oxygen as the oxidant under atmospheric pressure and room temperature in a decent yield. Compared to the previous method with CrO3, such a protocol avoids the use of a stoichiometric amount of oxidant, and the workup procedure is much more eco-friendly and convenient affording a higher yield of the product. Georg Thieme Verlag Stuttgart . New York.
- Liu, Jinxian,Ma, Shengming
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Read Online
- Ethynylhydroxycarbene (H-CC-C¨-OH)
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The species on the C3H2O potential energy surface have long been known to play a vital role in extraterrestrial chemistry. Here we report on the hitherto uncharacterized isomer ethynylhydroxycarbene (H-CC-C¨-OH, 1) generated by high-vacuum flash pyrolysis of ethynylglyoxylic acid ethyl ester and trapped in solid argon matrices at 3 and 20 K. Upon irradiation at 436 nm trans-1 rearranges to its higher lying cis-conformer. Prolonged irradiation leads to the formation of propynal. When the matrix is kept in the dark, 1 reacts within a half-life of ca. 70 h to propynal in a conformer-specific [1,2]H-tunneling process. Our results are fully consistent with computations at the CCSD(T)/cc-pVTZ and the B3LYP/def2-QZVPP levels of theory.
- Bernhardt, Bastian,Ruth, Marcel,Eckhardt, André K.,Schreiner, Peter R.
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supporting information
p. 3741 - 3746
(2021/04/06)
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- PROTEASOME INHIBITING ?-LACTAM PRODRUGS USEFUL FOR THE TREATMENT OF CANCER AND NEURODEGENERATIVE DISORDERS
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The present invention relates generally to proteasome inhibiting β-lactam compounds useful for the treatment of cancer and neurodegenerative disorders. The invention also provides pharmaceutical compositions and extended release formulations of said compounds, and medical uses of said compounds and/or pharmaceutical compositions to treat cancer and neurodegenerative disorders.
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Page/Page column 53; 54; 55
(2018/07/29)
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- DABCO-bis-CC: An efficient alternative to PCC
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We have developed a new chromium based reagent ‘DABCO?bis-CC’ for the straightforward oxidation of alcohols to corresponding carbonyl compounds with high efficiency. The present results demonstrate a broad range of alcohols including primary, secondary, aliphatic, benzylic and heterocyclic alcohols are tolerated as substrates at room temperature.
- Saikia, Bishwajit
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p. 583 - 586
(2018/06/26)
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- Chiral Supramolecular U-Shaped Catalysts Induce the Multiselective Diels-Alder Reaction of Propargyl Aldehyde
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The Diels-Alder reaction, which is a traditional [4 + 2] cycloaddition with two carbon-carbon bond formations, is one of the most powerful tools to synthesize versatile and unique six-membered rings. We show that chiral supramolecular U-shaped boron Lewis acid catalysts promote the unprecedented multiselective Diels-Alder reaction of propargyl aldehyde with cyclic dienes. Independent from the substrate control, enantio-, endo/exo-, π-facial-, regio-, site-, and substrate-selectivities could be controlled by the present U-shaped catalysts. The obtained reaction products could access the concise synthesis of chiral diene ligands and a key intermediate of (+)-sarkomycin. The results presented here might partially contribute to the development of artificial enzyme-like supramolecular catalysts for multiselective reactions, which will be able to target organic compounds that have thus far eluded synthesis.
- Hatano, Manabu,Sakamoto, Tatsuhiro,Mizuno, Tomokazu,Goto, Yuta,Ishihara, Kazuaki
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supporting information
p. 16253 - 16263
(2018/11/27)
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- Reactivity of indole-3-alkoxides in the absence of acids: Rapid synthesis of homo-bisindolylmethanes
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An unprecedented behaviour of in situ generated indole-3-alkoxides (MgX or Li) has been reported. Tuning the electronic properties of the alkoxides offered the direct and selective construction of bisindolylmethanes and indole-3-carbinols. This process shows very broad scope and represents the reagent (external) free, greener synthesis of structurally divergent bisindolylmethanes.
- Chinta, Bhavani Shankar,Baire, Beeraiah
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p. 8106 - 8116
(2016/11/22)
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- Silica supported Thallium (III) Nitrate: An effective oxidant for oxidation of alcohols to the carbonyl compounds
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Thallium (III) Nitrate Supported on Silica gel was found to be an efficient reagent system for oxidation of primary and secondary alcohols to their corresponding carbonyl compounds under mild conditions. The striking features of our method are: short reaction times, formation of no over oxidation products due to high selectivity and mild nature of oxidant, easy work-up procedure, high yields and carbon carbon double or triple bond functional group in the alcohol structure does not oxidize to other group.
- Manesh, Abbas Amini,Nazari, Tahereh
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p. 3001 - 3004
(2015/11/27)
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- Immobilized magnetic nano catalyst for oxidation of alcohol
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Covalent attachment of Schiff base on magnetic nanoparticles yielded good selectivity for oxidation of alcohols. The ferromagnetic interaction in the complex added comprehensive advantage in enhancing the catalytic activity of the nanocatalyst. A greener approach for alcohol oxidation was achieved in solventless method with good yield (>78%). Leaching experiments confirmed a strong interaction between magnetic support and complex. The catalyst showed significant conversion even after 5 catalytic runs.
- Bhat, Pooja B.,Rajarao, Ravindra,Sahajwalla, Veena,Bhat, Badekai Ramachandra
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- An immobilised Co(ii) and Ni(ii) Schiff base magnetic nanocatalyst via a click reaction: A greener approach for alcohol oxidation
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A Schiff base immobilised nanocatalyst was synthesized via copper catalysed alkyne azide cycloaddition (CuAAC) on a magnetic support. The nanocatalyst exhibited high accessible active sites with a surface area of 76 m2 g-1 for a cobalt complex and 57 m2 g-1 for a nickel complex. A strong interaction between the magnetic support and the Schiff base was achieved by avoiding leaching during the course of reaction. The nanocatalyst efficiently oxidised both primary and secondary alcohols to carbonyl with improved yield in a solventless system rendering a greener approach.
- Bhat, Pooja B.,Bhat, Badekai Ramachandra
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p. 4933 - 4938
(2015/06/16)
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- Nickel hydroxide/cobalt-ferrite magnetic nanocatalyst for alcohol oxidation
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A magnetically separable, active nickel hydroxide (Bronsted base) coated nanocobalt ferrite catalyst has been developed for oxidation of alcohols. High surface area was achieved by tuning the particle size with surfactant. The surface area of 120.94 m2 g-1 has been achieved for the coated nanocobalt ferrite. Improved catalytic activity and selectivity were obtained by synergistic effect of transition metal hydroxide (basic hydroxide) on nanocobalt ferrite. The nanocatalyst oxidizes primary and secondary alcohols efficiently (87%) to corresponding carbonyls in good yields.
- Bhat, Pooja B.,Inam, Fawad,Bhat, Badekai Ramachandra
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p. 397 - 402
(2014/09/17)
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- An efficient copper-catalysed pyrrole synthesis
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Copper-catalysed cyclisations of β-hydroxyhomopropargylic sulfonamides can be carried out using copper(II) acetate in hot toluene to provide generally excellent yields of the corresponding pyrroles. ARKAT-USA, Inc.
- Dunford, Damian G.,Knight, David W.,Wheeler, Robert C.
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p. 253 - 273
(2013/01/16)
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- Propynal equivalents and diazopropyne: Synthesis of all mono-13C isotopomers
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Mechanistic and spectroscopic investigations of reactive C 3H2 hydrocarbons necessitated the preparation of diazopropyne isotopomers bearing mono-13C substitution at each of the three unique positions. The diazo compounds and their tosylhydrazone precursors were prepared from the mono-13C isotopomers of propynal (in the form of either the aldehyde or the diethyl acetal). The introduction of 13C-labeling at either alkyne position in propynal utilized the Corey - Fuchs procedure for chain homologation.
- Seburg, Randal A.,Hodges, Jonathan A.,McMahon, Robert J.
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experimental part
p. 1626 - 1643
(2009/10/17)
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- Preparation and structure of some sulfanylpropenylidene derivatives of Meldrum's acid
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Condensation of Meldrum's acid with the 3-sulfanylpropenal derivatives 7a and 7b gives the 3-sulfanylpropenylidene derivatives 2a and 2b, respectively. NMR and X-ray analysis of 2a and 2b show that the electron-donating group conjugates with the electron-
- Crawford, Lynne A.,Mcnab, Hamish
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body text
p. 995 - 1009
(2010/03/01)
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- Dimethyl sulfoxide pivaloyl chloride: A new reagent for oxidation of alcohols to carbonyls
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An efficient procedure for conversion of alcohols to the corresponding carbonyl compounds, an alternative to the classical Swern oxidation, is described. Pivaloyl chloride is employed as a mild and inexpensive electrophile. A possible reaction mechanism is proposed. Copyright Taylor & Francis Group, LLC.
- Dubey, Abhishek,Kandula, Subba Rao V.,Kumar, Pradeep
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p. 746 - 753
(2008/09/16)
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- PROCESS FOR THE PREPARATION OF N-METHYL ANILINO ACROLEIN
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This present invention relates to processes for the preparation of 3-N-methyl-N-phenylaminoacroline.
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Page/Page column 11-12
(2008/06/13)
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- Dielectric activation of MnO2: Part 1 - Oxidation of conjugated unsaturated alcohols
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The activation of 'wet' precipitated manganese dioxide through an environmentally benign and expeditious pathway involving the use of a specially manoeuvered domestic microwave oven and its applicability in several organic solvents for near quantitative conversion of a range of conjugated unsaturated alcohols is demonstrated. The protocol effectively replaces procedures that are strenuous, hazardous and prohibitively time consuming. Again compatibility in almost all common organic solvents offers additional advantages e.g. control over precise activation and remarkable flexibility in the choice of substrates and conditions.
- Lai, Tapan K.,Banerji, Julie,Chatterjee, Asima,Basak, Bidyut
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p. 1309 - 1311
(2007/10/03)
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- 1,3-Dipolar cycloaddition in the synthesis of pyrazolyl-substituted nitronyl nitroxides
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A new approach to the synthesis of polyfunctional pyrazolyl-substituted nitronyl nitroxides was developed based on the presynthesized pyrazole derivatives prepared by 1,3-dipolar cycloaddition. The structures of the resulting mono- and biradicals were confirmed by X-ray diffraction.
- Tretyakov,Tolstikov,Romanenko,Shvedenkov,Sagdeev,Ovcharenko
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p. 2169 - 2181
(2007/10/03)
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- Partial oxidation of alcohols to aldehydes and ketones under mild conditions
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A number of aldehydes and ketones were prepared by partial oxidation of alcohols in air catalyzed by RuO2/ZSM-5 which can be easily prepared with the industrial grade ZSM-5 and RuCl3·xH2O.
- Qian, Guang,Zhao, Rui,Lu, Gaomeng,Qi, Yanxing,Suo, Jishuan
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p. 1753 - 1758
(2007/10/03)
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- Synthesis and biological evaluation of novel 1β-methylcarbapenems with isothiazoloethenyl side chains
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The synthesis of novel 1β-methylcarbapenems 1a,b bearing isothiazoloethenyl moieties at C-5 position of pyrrolidine ring and their biological evaluation are described. Both compounds showed potent and well-balanced antibacterial activity as well as high stability to DHP-I. Especially, 5-isothiazole derivative 1a exhibited excellent DHP-I stability and advanced pharmacokinetics profiles, compared to 5-isoxazole derivative 2, imipenem, and meropenem.
- Kang, Yong Koo,Lee, Kyung Seok,Yoo, Kyung Ho,Shin, Kye Jung,Kim, Dong Chan,Lee, Chang-Seok,Kong, Jae Yang,Kim, Dong Jin
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p. 463 - 466
(2007/10/03)
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- Preparation of preparing substituted indanones
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a process for the preparation of indanones of the formula II from, indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia comprises reacting an indanone of the formula I or Ia with a coupling component.
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- Alcoholysis of 2,2-dichloropropyl derivatives of carbazole, phenothiazine, and phenoxazine
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Reactions of 9-(2,2-dichlorocyclopropyl)carbazole, 10-(2,2-dichlorocyclopropyl)phenothiazine, and 10-(2,2-dichlorocyclopropyl)phenoxazine with alcohols in the system t-BuOK-DMSO yield the corresponding N-(1-alkoxy-2-propynyl) derivatives. Hydrolysis of 9-(1-methoxy-2-propynyl)carbazole and 10-(1-methoxy-2-propynyl)phenothiazine in 60% aqueous dioxane in the presence of sulfuric acid gives the corresponding heterocyclic amine and 2-propynal. ? Deceased.
- Anfinogenov,Okhtemenko,Khlebnikov,Ogorodnikov
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p. 112 - 115
(2007/10/03)
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- π Conjugation across the tetrathiafulvalene core: Synthesis of extended tetrathiafulvalene derivatives and theoretical analysis of their unusual electrochemical properties
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A series of extended tetrathiafulvalene (TTF) derivatives bearing one or two 1,4-dithiafulven-6-yl substituents has been prepared. The new compounds present remarkable electrochemical singularities compared with other TTF derivatives, which are strongly affected by the nature of the substitution on the lateral heterocycle(s). This unusual electrochemical behaviour follows a square-scheme sequence and is attributed to structural changes upon oxidation of the π-donating molecules. Digital simulations of the electrochemical data have been used to reach the values of the kinetic and thermodynamic constants involved in the square scheme. Theoretical calculations establish an important contribution of a highly delocalised resonant form involving a tetravalent sulphur in oxidised species, which could justify the occurrence of an electrochemical behaviour distinct from that of TTF. Finally, third- order susceptibilities χ3 of two of these systems, for which electron- donating and electron-withdrawing substituents coexist and are conjugated through the TTF π system, are given.
- Terkia-Derdra, Najoua,Andreu, Raquel,Salle, Marc,Levillain, Eric,Orduna, Jesus,Garin, Javier,Orti, Enrique,Viruela, Rafael,Pou-Amerigo, Rosendo,Sahraoui, Bouchta,Gorgues, Alain,Favard, Jean-Francois,Riou, Amedee
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p. 1199 - 1213
(2007/10/03)
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- Synthesis and cytotoxicity studies of new analogues of polyamines
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In order to regulate simultaneously the biosynthesis and the transport of natural polyamines, the synthesis of a series of N-methylated analogues of N,N'-Bis(benzyl)-alkanediamines (propanediamine and butanediamine) was achieved and the cytotoxicity of these compounds on the P388D1 cell line was determined. Experiments were conducted in a growth culture medium 20 μM of 2-mercaptoethanol or 0.1 mM of aminoguanidine. Their cytotoxic effects were compared to those obtained under the same conditions with natural polyamines known as toxic compounds at high concentrations. The IC50 of each compound was found very similar for all experimental conditions (IC50 ~150 μM) at the opposite of spermidine and spermine which were less toxic (IC50 >500 μM) when cells were grown in the presence of aminoguanidine (a specific inhibitor of fetal calf serum's PAO). THe DL-difluoromethylornithine (DEMO) and MDL 72527DA, two well known inhibitors of ornithine decarboxylase (ODC) and Polyamine Oxidase (PAO) respectively, had no toxicity on the P388D1 cells compared to our compounds. Our most toxic compound was N1,N4-Bis(benzyl)-N1,N4-bis(methyl)-1,4-butanediamine (6) with an IC50 of 127 ± 3 μM (in culture medium alone). The synthesis of the β-aminothioether derivative of N-benzylputrescine (11) and the β-aminothiol derivative of N-benzylspermidine (13) were also related. The Compound 11 was tested against the P388D1 cells, and did not show any cytotoxic effect. The N-methyl derivatives should give the advantage to be used at low concentrations than those used to test the DFMO.
- Badolo, Lassina,Gelbcke,Dubois,Hanocq
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- A Short, Convenient Synthesis of Propynal
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Propynal 1 is obtained in 80% yield on a preparative scale by flash vacuum pyrolysis of diprop-2-ynyl ether 3.
- McNab, Hamish,Morel, Gilles,Stevenson, Elizabeth
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p. 207 - 207
(2007/10/03)
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- Kinetics and mechanism of oxidation of allyl, crotyl and propargyl alcohols by diperiodato cuprate(III) in alkaline medium
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The kinetics and mechanism of oxidation of α, β-unsaturated alcohols (UA) such as allyl, crotyl and propargyl alcohols by periodate complex of trivalent copper in aqueous alkaline medium has been studied spectrophotometrically at 416 nm.The order in and is found to be unity each.The rate decreases with increase in and increases with increase in ->.There is no effect of addition of salts like Na2SO4 and KNO3.The primary kinetic isotopic effect kH/kD is 3.87 at 313 K.The solvent isotopic effect kH2O/kD2O is 0.912 at 313 K.The product of oxidation has been identified as the corresponding aldehyde.Participation of double bond in the oxidation reaction has not been observed.Under the experimental conditions monoperiodato cuprate(III) species has been assumed to be the active species.The results are discussed in terms of +I effect of methyl group and resonance stabilisation of free radical.The observed results are explained in terms of an outersphere electron transfer mechanism.
- Padmaja, S.,Rao, K. Nageshwar,Sethuram, B.
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p. 685 - 688
(2007/10/02)
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- The Influence of Intramolecular Dynamics on Branching Ratios in Thermal Rearrangements
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1- and 2-phenylbicyclohex-2-enes-5-d undergo thermal rearrangement to give products, differing only in the location of the deuterium, in ratio of about 9:1, but with identical activation enthalphies.Similarly, opticallly active trans-2-methyl-1-(trans-2-phenylethenyl)cyclopropane is found to rearrange to enantiomeric methylphenylcyclopentenes that are formed in a 5.9:1 ratio but with virtually identicyl activation enthalphies.Barring repeated coincidence, these results do not seem to be explicable within the framework of statistical theories of unimolecular kinetics such as RRKM theory, transition state theory, and variational transition state theory.The possible influence of dynamic effects in these and other unimolecular reactions is discussed.
- Newmann-Evans, Richard H.,Simon, Reyna J.,Carpenter, B. K.
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p. 695 - 711
(2007/10/02)
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- Thermal Oxidative Deamination of Aliphatic Amines to Aldehydes with Bis(diphenylphosphinyl) Peroxide
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Reaction of N-substituted alkylamines having pseudoacidic hydrogen at the 1-methylene group with bis(diphenylphosphinyl) peroxide yields the deaminated products by thermal elimination of diphenylphosphinic acid from the intermediate O-diphenylphosphinylhydroxylamines.
- Masse, Guy,Sturtz, Georges
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p. 907 - 910
(2007/10/02)
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- Oxidative Breaking of Long-Chain Acetylenic Enol Ethers of Glycerol of the Marine Sponges Raspailia pumila and R. ramosa and of Model Compounds with Aerial Oxygen
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The raspailynes (novel long-chain enol ethers of glycerol having the enol ether double bond conjugated, in sequence, to an acetylenic and an olefinic bond, isolated from the North-East-Atlantic sponges Raspailia pumila and R. ramosa) are stable under normal hydrolytic conditions for enol ethers.In contrast, when their solutions are evaporated, these lipids such as raspailyne B1 (=(-)-3--1,2-propanediol; (-)-2) rapidly react with aerial O2 under normal laboratory-daylight conditions, with rupture of the C=C enol ether bond to give 1-O-formylglycerol (3) and an aldehyde (such as tridec-4-en-3-ynal(4) from (-)-2).This reaction must be caused by triplet O2, since thermally generated singlet O2 has no effect on (-)-2 in solution.That the mere presence of an enol-ether moiety conjugated to an acetylenic group is responsible for such a behaviour is demonstrated with the model compounds 1-methoxypentadec-1-en-3-yn-5-ol (6a) and its 5-O-acetyl or 5-O-tetrahydropyranyl derivatives 6b and 6c, respectively.Resistance to both hydrolytic conditions and singlet O2 of these compounds is thought to arise from electron depletion at the enol-ether C(β) atom by the acetylenic group.Plausible reaction pathways for enol-ether bond rupture in these compounds by aerial O2 are outlined.
- Guella, Graziano,Mancini, Ines,Pietra, Francesco
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p. 1400 - 1411
(2007/10/02)
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- NEUE WEGE ZUM CYCLOBUTADIEN UND METHYLENCYCLOPROPEN
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New routes to cyclobutadiene (2) and methylenecyclopropene (4) are described.Matrix irradiation of cyclopropenylketene (9) gives cyclobutadiene.Flash pyrolysis of 8, 11, 16, 17 and 18 also generates cyclobutadiene, which can be deposited from the gas phase onto a window cooled to 10 K.Methylenecyclopropene is one of he products in the thermal fragmentation of 8 or 14.
- Maier, Guenther,Hoppe, Manfred,Lanz, Klaus,Reisenauer, Hans Peter
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p. 5645 - 5648
(2007/10/02)
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- Singlet Oxygenation of But-1-en-3-ynes: on the Possible Intermediacy of a 1,2-Dioxacyclohexa-3,4-diene
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But-1-en-3-ynes undergo singlet oxygenation resulting in the formation of products rationalized as being derived from 1,2-dioxacyclohexa-3,4-dienes; ab initio calculations for such an intermediate are reported.
- Lee-Ruff, Edward,Maleki, Mehran,Duperrouzel, Paul,Lien, Min H.,Hopkinson, Alan C.
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p. 346 - 347
(2007/10/02)
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- Synthesis and Diels-Alder reactions of (E)-6,6-dimethoxy-3-hexen-2-one
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Treatment of 3,3-dimethoxypropanal (2) with (acetylmethylene)triphenylphosphorane (4) gives (E)-6,6-dimethoxy-3-hexen-2-one (5).Reaction of 5 with cyclopentadiene, 1,3-cyclohexadiene, anthracene, and 1,3-diphenylisobenzofuran gives Diels-Alder adducts, which on hydrolysis are converted to the corresponding keto aldehydes.Attempts to effect intramolecular aldol condensation of the latter were unsuccessful.Hydrolysis of the exo-acetyl adduct from 1,3-diphenylisobenzofuran with aqueous formic acid gives 4-acetyl-2,3,3a,4,5,9b-hexahydro-5,9b-diphenylnaphthofuran-2,5-diol, via aldehyde formation and hydrolytic cleavage of the ether bridge.The adduct from cyclopentadiene under anhydrous acid conditions give 3-acetyl-9-methoxy-tetracyclo2,4.03,7>nonane (27).
- Yates, Peter,Douglas, Stephen Paul
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p. 2760 - 2765
(2007/10/02)
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- Metabolic depropargylation and its relationship to aldehyde dehydrogenase inhibition in vivo
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The relationship between metabolic depropargylation in vitro to inhibition of the low K(m) aldehyde dehydrogenase (AIDH) of rat liver mitochondria in vivo was determined for a number of compounds bearing a propargyl substituent on nitrogen or oxygen. Only those compounds which enzymatically released the highly reactive α, β-acetylenic aldehyde, propiolaldehyde, when incubated in vitro with phenobarbital-induced rat liver microsomes, e.g., tripropargylamine (4), pargyline (1a), and N-propargylbenzylamine (1b), significantly elevated blood acetaldehyde levels when administered in vivo. Mitochondrial AlDH activity in these animals was corresponding reduced to ≤20% that of control animals. Compounds that did not inhibit mitochondrial AlDH activity to this degree did not produce significant levels of propiolaldehyde when incubated with microsomes. Thus, for this series of compounds, metabolic depropargylation is a requirement for AlDH inhibitory activity in vivo.
- Shirota,DeMaster,Elberling,Nagasawa
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p. 669 - 673
(2007/10/02)
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