- CATALYTIC OXIDATION OF ALDEHYDES TO CARBOXYLIC ACIDS WITH HYDROGEN PEROXYDE AS OXIDANT
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Alkyl and aryl aldehydes were catalytically oxidized to carboxylic acids in high yields with hydrogen peroxide as oxidant using benseneseleninic acid as catalyst.
- Choi, Joong-Kwon,Chang, Young-Kil,Hong, Sung Yeap
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- Correlation of rates of uncatalyzed and hydroxide-ion catalyzed ketene hydration. A mechanistic application and solvent isotope effects on the uncatalyzed reaction
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Rates of hydration of a number of ketenes were measured in neutral and basic solution using flash photolytic techniques, and rate constants for their uncatalyzed, k(uc), and hydroxide-ion catalyzed, k(HO), reactions were determined. These results, plus additional data from the literature, were found to provide the remarkably good correlation log k(uc) = -3.21 + 1.14 log k(HO), which spans 10 orders of magnitude in reactivity and includes 31 ketenes. This good correlation implies that uncatalyzed and hydroxide-ion catalyzed ketene hydraton occur by similar reaction mechanisms, which for the hydroxide-ion catalyzed process is known to involve nucleophilic attack on the carbonyl carbon atom of the ketene. Rate constants for phenylhydroxyketene, on the other hand, do not fit this correlation, which suggests that the mechanistic assignment upon which these rate constants are based may not be correct. Solvent isotope effects on these uncatalyzed ketene hydrations are weak; most are less than k(H)/k(D) = 2. It is argued that these isotope effects are largely, if not entirely, secondary in nature and that they are consistent with both a reaction mechanism in which nucleophilic attack of a single water molecule on the ketene carbonyl carbon atom produces a zwitterionic intermediate and also a mechanism that avoids this intermediate by passing through a cyclic transition state involving several water molecules.
- Andraos, John,Kresge, A. Jerry
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- Novel diastereoselective synthesis of (E)-gem-dimetalloalkenes containing boron and germanium: An easy access to alkyl trimethylgermyl ketones and carboxylic acids
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A convenient, novel synthesis of (E)-gem-dimetalloalkenes containing boron and germanium from the (Z)-1-bromo-1-alkenylboronate esters has been developed. α-Bromo-(Z)-1-alkenylboronate esters readily prepared from the literature procedures smoothly underwent a reaction with freshly generated trimethylgermyllithium in hexamethylphosphoramide (HMPA) from the hexamethyldigermanium at -78°C to provide the corresponding 'ate' complexes. These 'ate' complexes underwent intramolecular nucleophilic substitution reaction to provide the corresponding (E)-1-alkenylboronate esters containing trimethylgermyl moiety. These intermediates were isolated in good yields (72-81%) and were characterized by the spectral data (1H NMR and 13C NMR). Upon oxidation of these intermediates with trimethylamine-N-oxide, the corresponding alkyl trimethylgermyl ketones were prepared in good yields (78-86%)). Oxidation with alkaline hydrogen peroxide followed by acidification afforded the corresponding carboxylic acids in good yields (82-88%). Georg Thieme Verlag Stuttgart.
- Bhat, Narayan G.,Varghese, Nisha
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- Organoboranes for Synthesis. 14. Convenient Procedures for the Direct Oxidation of Organoboranes from Terminal Alkenes to Carboxylic Acids
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For the first time, a highly efficient and direct oxidation of a variety of organoborane intermediates into carboxylic acids has been demonstrated, without an increase or decrease of carbon atoms.Synthetically useful procedures have been developed for the ready conversion of representative terminal alkenes into carboxylic acids via oxidation of the organoboranes obtained by hydroboration of the terminal alkenes.The oxidation works well with a variety of organoboranes derived from reagents such as dibromoborane-methyl sulfide (HBBr2*SMe2), monobromoborane-methyl sulfide (H2BBr*SMe2), monochloroboran-methyl sulfide (H2BCl*SMe2), borane-methyl sulfide (H3B*SMe2), thexylborane (H2BThx), and dicyclohexylborane (HBChx2).The oxidation is achieved in a convenient manner with pyridinium dichromate (PDC), sodium dichromate in aqueous sulfuric acid (Na2Cr2O7-H2SO4) and chromium trioxide in 90 percent aqueous acetic acid (CrO3-HOAc-H2O).These oxidations afford carboxylic acids in very good yields with complete retention of the structure of the organic group attached to boron.
- Brown, Herbert C.,Kulkarni, Shekhar V.,Khanna, Vijay V.,Patil, Virendra D.,Racherla, Uday S.
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- Ni(I)-Alkyl Complexes Bearing Phenanthroline Ligands: Experimental Evidence for CO2Insertion at Ni(I) Centers
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Although the catalytic carboxylation of unactivated alkyl electrophiles has reached remarkable levels of sophistication, the intermediacy of (phenanthroline)Ni(I)-alkyl species - complexes proposed in numerous Ni-catalyzed reductive cross-coupling reactions - has been subject to speculation. Herein we report the synthesis of such elusive (phenanthroline)Ni(I) species and their reactivity with CO2, allowing us to address a long-standing question related to Ni-catalyzed carboxylation reactions.
- Hazari, Nilay,Hopmann, Kathrin H.,Martin, Ruben,Obst, Marc F.,Odena, Carlota,Somerville, Rosie J.
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- A convenient procedure for the direct conversion of terminal alkenes into carboxylic acids
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Alkylboronic acids, readily synthesized from a variety of representative terminal alkenes via hydroboration with dibromoborane-methyl sulfide, undergo a facile oxidation with chromium trioxide in 90% aqueous acetic acid to provide carboxylic acids in 80-97% isolated yields, without rearrangement or loss of carbon.
- Racherla,Khanna,Brown
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- Oxidation of Alkynyl Boronates to Carboxylic Acids, Esters, and Amides
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A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides through oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)?B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformation. Notably, amino acids and peptides can be used as nucleophiles, providing an efficient method for the synthesis and modification of peptides. The practicability of this methodology was further highlighted by the preparation of pharmaceutical molecules.
- Li, Chenchen,Li, Ruoling,Zhang, Bing,Zhao, Pei,Zhao, Wanxiang
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supporting information
p. 10913 - 10917
(2020/05/25)
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- Preparation method of bimetallic catalyst oxidation aldehyde synthetic carboxylic acid (by machine translation)
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The method is, in a reaction solvent: under normal pressure oxygen condition, under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a bimetallic catalyst, at, DEG, under stirring . under a stirring condition with an aldehyde compound as a substrate 10-90 °C in a reaction solvent under, a stirring condition under the action of a bimetallic catalyst . The reaction solution is stirred, for. 1-12h, hours at; room temperature, under, the action, of a bimetallic 1:1 catalyst Cu(OAc) under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a double-metal catalyst. 2 · H2 O And Co(OAc)2 · 44H2 O As the bimetallic catalyst, can achieve the highest yield of the carboxylic acid product, in high yield, by adjusting the reaction temperature, solvent, catalyst amount, for different types of the raw material aldehyde 98%. (by machine translation)
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Paragraph 0046-0047
(2020/05/30)
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- Organocatalyzed Aerobic Oxidation of Aldehydes to Acids
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The first example organocatalyzed aerobic oxidation of aldehydes to carboxylic acids in both organic solvent and water under mild conditions is developed. As low as 5 mol % N-hydroxyphthalimide was used as the organocatalyst, and molecular O2 was used as the sole oxidant. No transition metals or hazardous oxidants or cocatalysts were involved. A wide range of carboxylic acids bearing diverse functional groups were obtained from aldehydes, even from alcohols, in high yields.
- Dai, Peng-Fei,Qu, Jian-Ping,Kang, Yan-Biao
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supporting information
p. 1393 - 1396
(2019/02/26)
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- A aldehyde or mellow directly converted into the carboxylic acid (by machine translation)
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The invention discloses a aldehyde or mellow oxidation can be directly transformed into carboxylic acid, is characterized in that the pure oxygen environment, in N - hydroxy imide compound under the catalysis of the imide compound or N - hydroxy and nitrous acid ester compound common under the catalysis, the CH2 OH and CHO oxidation directly converted into the carboxylic acid compounds. The invention using oxygen as the oxidizing agent, does not add any metal catalyst, environment-friendly, high catalytic efficiency, simple and convenient operation. With the previous metal catalytic system complex and different catalytic system, has some metal catalytic system in the process, the use of transition metal will cause the transition metal of the residual, the invention adopts the non-metallic catalytic system, environmental protection, preventing the metal residue problem, this to the solution of the drug in the synthesis of transition metal residue problem and provides a new method of thinking. (by machine translation)
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Paragraph 0031; 0032
(2018/08/03)
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- Biomimetic flavin-catalyzed aldehyde oxidation
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The oxidation of alkyl and aryl aldehydes to their corresponding carboxylic acids has been achieved through the action of a biomimetic bridged flavin catalyst. The reaction uses readily available 35% aqueous hydrogen peroxide and is operationally simple. The oxidation is a green and sustainable reaction, obviating chlorinated solvents with minimal byproducts.
- Murray, Alexander T.,Matton, Pascal,Fairhurst, Nathan W. G.,John, Matthew P.,Carbery, David R.
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supporting information; experimental part
p. 3656 - 3659
(2012/08/28)
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- Hypervalent λ3-bromane strategy for Baeyer-Villiger oxidation: Selective transformation of primary aliphatic and aromatic aldehydes to formates, which is missing in the classical Baeyer-Villiger oxidation
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A conceptually distinct, modern strategy for Baeyer-Villiger oxidation (BVO) was developed. Our novel method involves initial hydration of water to carbonyl compounds, followed by ligand exchange of hypervalent aryl-λ3-bromane on bromane(III) with the resulting hydrate, yielding a new type of activated Criegee intermediate. The intermediate undergoes BV rearrangement and produces an ester via facile reductive elimination of an aryl-λ3-bromanyl group, because of the hypernucleofugality. The novel strategy makes it possible to induce selectively the BV rearrangement of straight chain primary aliphatic as well as aromatic aldehydes, which is missing in the classical BVO: for instance, octanal and benzaldehyde afforded rearranged formate esters with high selectivity (>95%) under our conditions, while the attempted classical BVO produced only carboxylic acids. This firmly establishes the powerful nature of new methodology for BVO.
- Ochiai, Masahito,Yoshimura, Akira,Miyamoto, Kazunori,Hayashi, Satoko,Nakanishi, Waro
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supporting information; experimental part
p. 9236 - 9239
(2010/11/02)
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- Structure activity studies with xenobiotic substrates using carboxylesterases isolated from Arabidopsis thaliana
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Carboxylesterases (CXEs) catalyse the hydrolysis of xenobiotics and natural products radically altering their biological activities. Whereas the substrate selectivity of animal CXEs, such as porcine liver esterase (PLE) have been well studied, the respective enzymes in plants have yet to be defined and their activities determined. Using Arabidopsis thaliana (At) as a source, five representative members of the α/β hydrolase AtCXE family of proteins have been cloned, expressed and the purified recombinant proteins assayed for esterase activity with xenobiotic substrates. Two members, AtCXE5 and AtCXE18 were found to be active carboxylesterases, though AtCXE5 proved to be highly unstable as a soluble protein. AtCXE18 and the previously characterised S-formylglutathione hydrolase from Arabidopsis (AtSFGH) were assayed against a series of esters based on methylumbelliferone in which the acyl moiety was varied with respect to size and conformation. The same series was used to assay crude esterase preparation from Arabidopsis plants and the results compared with those obtained with the commonly used PLE. With straight chain esters, AtCXE18 behaved like PLE, but the Arabidopsis hydrolases proved less tolerant of branched chain acyl components than the mammalian enzyme. While none of the enzyme preparations accurately reflected all the activities determined with crude Arabidopsis protein extracts, the plant enzymes proved more useful than PLE in predicting the hydrolysis of the more sterically constrained esters.
- Cummins, Ian,Landrum, Marie,Steel, Patrick G.,Edwards, Robert
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p. 811 - 818
(2008/03/13)
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- Structure and reactivity in the hydrolyses of aliphatic carboxylic acid esters and chlorides
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For hexanoic acid and its seven isomers, relative rates have been determined for acid catalysed esterification with methanol, and compared with those for saponification of the methyl esters. A good correlation between logarithms of relative rates for the two reactions is obtained, and it is suggested that the eight isomers provide a test set of compounds in which steric effects alone act on reactivity at the acyl carbon. A full set of steric parameters (Es′ values) are presented. Rates of solvolyses of the acid chlorides- of the isomers have been determined conductometrically in 3:1 wt:wt acetonitrile water. Logarithms of relative rates show a poor correlation with Es′, and, taking into account the solvent dependence of the rates, the pattern excludes both rate-limiting formation of a tetrahedral intermediate and rate-limiting dissociation of chloride to form acylium ions. The remaining possibilities, a concerted process (ANDN?) and rapid reversible formation of a hydrate followed by rate-limiting dissociation of chloride (AN + DN?,) are considered. Copyright
- Regan, Andrew C.,Watt, C. Ian F.
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p. 180 - 189
(2008/02/06)
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- A novel synthesis of (Z)-2-(1-trimethylgermyl-1-alkenyl)-1,3,2- dioxaborinanes and their conversion into carboxylic acids
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A novel procedure for preparing heterocyclic compounds such as (Z)-2-(1-trimethylgermyl-1-alkenyl)-1,3,2-dioxaborinanes based on 1-trimethylgermyl-1-alkynes is described. 1-Trimethylgermyl-1-alkynes easily obtainable by deprotonation of 1-alkynes with n-butyllithium followed by treatment with trimethylgermanium chloride, are readily hydroborated in n-pentane in the presence of boron trichloride in hexane at 0°C for 3 h. The resulting supernatant clear solution was separated from boron trichloride-methyl sulfide complex. It was then reacted with 1,3-propane diol at 0°C for 0.5 h. The resulting representative (Z)-2-(1-trimethylgermyl-1- alkenyl)-1,3,2-dioxaborinanes were isolated in good yields (65-86%) and in high stereochemical purities (>98%) as evidenced by NMR spectral data. The carbon skeletons present in these intermediates were confirmed by alkaline hydrogen peroxide oxidation to the corresponding carboxylic acids.
- Bhat, Narayan G.,Caga-Anan, Zerremi,Leija, Reynaldo
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p. 5109 - 5111
(2007/10/03)
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- Synthesis of 3,3,-dimethylbutyraldehyde by the reduction of 3,3,-dimethylbutyric acid
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A process for the production of 3,3-dimethylbutyraldehyde is disclosed. The 3,3-dimethylbutyraldehyde is obtained by the reduction of 3,3-dimethylbutyric acid using trimethylacetic anhydride and a phosphine. The 3,3-dimethylbutyric acid is preferably obtained by a process in which tert-butanol and vinylidene chloride are reacted in the presence of sulfuric acid. The disclosed process has improved cost and yield.
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- Spirodiclofen and spiromesifen - Novel acaricidal and insecticidal tetronic acid derivatives with a new mode of action
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The broad spectrum acaricides spirodiclofen (BAJ2740, trade name: Envidor) and spiromesifen (BSN2060, trade name: Oberon) with an additional excellent activity against whiteflies, both belong to the new chemical class of tetronic acid derivatives discovered at Bayer CropScience during the 1990s. The discovery process starting from herbicidal PPO (protoporphyrinogen oxidase) chemistry, the synthetic routes leading to the products, and some insight into process development of central intermediates is given. Spirodiclofen and spiromesifen have a new mode of action (interference with lipid biosynthesis), show no cross-resistance to any resistant mite or whitefly field population and are therefore valuable tools for resistance management.
- Bretschneider, Thomas,Benet-Buchholz, Jordi,Fischer, Reiner,Nauen, Ralf
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p. 697 - 701
(2007/10/03)
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- Preparation of 3,3-dimethylbutyraldehyde by oxidation of 3,3-dimethylbutanol
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This invention provides a method for preparing 3,3-dimethylbutyraldehyde comprising the step of contacting 3,3-dimethylbutanol with an oxidizing metal oxide for a time and at a temperature sufficient for said metal oxide to oxidize 3,3-dimethylbutanol to form said 3,3-dimethylbutyraldehyde. The method of this invention provides a commercially practicable means of preparing 3,3-dimethylbutyraldehyde.
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Page column 3
(2008/06/13)
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- The autoxidation of aliphatic esters. Part 2. The autoxidation of neopentyl esters
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The autoxidation of six esters, neopentyl butanoate, 2,2-dimethylpropanoate, 3,3-dimethylbutanoate, 2,2-dimethylbutanoate, 2-methylbutanoate and 1,1-[2H2]-neopentyl butanoate, has been studied at 438 K. The reaction products were determined for each system and key reactions leading to the formation and further reactions of the primary products have been identified. Primary products include a range of hydroperoxides which lead to the formation of keto- and hydroxy-esters. Large amounts of neopentanol and the parent carboxylic acid are formed from each ester. It is shown that these are principally oxidation, and not hydrolysis, products. The relative rates of autoxidation of the first five esters mirror the relative rates of attack that occur on reaction with alkoxyl radicals; the sites of attack are on both the alkyl and acyl groups, with the α-alkyl hydrogen atoms on the ester showing particular vulnerability compared to the acyl hydrogen atoms. The analysis of products from the deuterated ester supports this conclusion.
- Lindsay Smith, John R.,Nagatomi, Eiji,Waddington, David J.
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p. 2248 - 2258
(2007/10/03)
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- Process for preparing 3.3-dimethylbutyric acid
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The present invention relates to a novel process for preparing 3,3-dimethylbutyric acid by reaction of trimethylpyruvic acid with hydrazine hydrate and treatment of the resulting hydrazone with a base.
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- Processes for producing aromatic polycarbonate oligomer and aromatic polycarbonate
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A process for producing continuously an aromatic polycarbonate oligomer by reacting an aromatic dihydroxy compound and an alkali metal base or an alkaline earth metal base with a carbonyl halide compound comprises: (1) feeding continuously to a tank reactor an aromatic dihydroxy compound, water, a molecular weight controlling agent, a polymerization catalyst, a carbonyl halide compound, and an organic solvent, and an alkali metal base or an alkaline earth metal base in an amount of 1.15-1.6 equivalents based on the aromatic dihydroxy compound, (2) carrying out the reaction with a residence time as defined by the following formula, where X is an amount of the polymerization catalyst in terms of mole % based on the amount of mole of the aromatic dihydroxy compound fed per unit time, and Y is a residence time (min.), and (3) continuously withdrawing the reaction mixture from the tank reactor to obtain an aromatic polycarbonate oligomer having a number average molecular weight of 1,000-10,000. An aromatic polycarbonate is produced by polycondensation of the aromatic polycarbonate oligomer.
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- HETEROCUMULENES IN ACYLATION REACTIONS II. REACTIVITY OF ALKYL-SUBSTITUTED KETENES IN SPONTANEOUS HYDROLYSIS REACTIONS
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The structures and electronic states of six ketenes were investigated by the semiempirical MNDO, MINDO/3, and AM1 quantum-chemical methods.The kinetics of the spontaneous hydrolysis of mono- and dialkylsubstituted ketenes in water and water-acetonitrile mixtures at 20 deg C were studied.The induction and steric effects of the substituents on the process rate were evaluated quantitatively in terms of a ρ? analysis.An increase in the number, length, and branching of the hydrocarbon substituents at the terminal carbon atom of the ketenes leads to a large decrease in the hydrolysis rate.The results of the calculations were compared with experimental data.Possible alternatives for the mechanism of the process are discussed.
- Lyashchuk, S. N.,Skrypnik, Yu. G.
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- The Oxidation of Ketones with a Heteropolyacid, H5 and Dioxygen
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Substituted cycloalkanones, 1-phenylalkanones, and open-chain ketones are oxidatively cleaved by the title compound under very mild conditions.
- Ali, Bassam El,Bregeault, Jean-Marie,Mercier, Jacqueline,Martin, Jacques,Martin, Claudine,Convert, Odile
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p. 825 - 826
(2007/10/02)
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- Electrophilic Additions to Alkynyl Tosylates. Formation of Vinyl 1,1-(Bis esters) and Related Compounds. X-ray Structure Determination of (E)-1-Chloro-1-(tosyloxy)-3,3-dimethyl-1-butene
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The reaction of alkynyl tosylates, RCCOTs, R=t-Bu, sec-Bu, with a variety of electrophiles, HCl, CF3COOH, CF3SO3H, ArSO3H, and H3O+, in CH2Cl2 is reported.Only regio- and stereospecific syn-monoaddition products were observed, yielding vinyl 1,1-(bis esters) and related compounds in good yields.The single-crystal X-ray data of the HCl adduct to t-BuCCOTs is reported.These results and their mechanistic implications are discussed.
- Stang, Peter J.,Roberts, Kenneth A.
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p. 5213 - 5217
(2007/10/02)
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- Improved Synthesis of Tertiary Alkylacetic Acids and Esters
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Tertiary alkylacetic acids (R3CCH2COOH) are prepared by reaction of 1,1-dichloroethene with a reagent capable of forming readily a tertiary alkyl carbenium ion with sulfuric acid in the absence of boron trifluoride.With tertiary butyl reagents, the yields are good and the method is convenient at laboratory and larger scales.The yields of carboxylic acids fall sharply with increasing steric effects.The esters are obtained directly, by adding alcohols, in a one-pot synthesis; with C1-C3 alcohols the reaction is selective.
- Randriamahefa, S.,Deschamps, P.,Gallo, R.,Grangette, H.
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p. 493 - 495
(2007/10/02)
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- AIR OXIDATION OF IN SITU OBTAINED CARBANIONS IN KOH-DME-CROWN SYSTEM
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KOH(NaOH)-dimethoxyethane-18-crown-6-O2 system has been found to be efficient for generation and oxidation of carbanions, obtained from monoarylmethanes.
- Artamkina, G.A.,Grinfel'd, A.A.,Beletskaya, I.P.
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p. 4989 - 4992
(2007/10/02)
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- SILAFUNCTIONAL COMPOUNDS IN ORGANIC SYMTHESIS. 21. HYDROGEN PEROXIDE OXIDATION OF ALKENYL(ALKOXY)SILANES
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The carbon-silicon bond in alkenyl(alkoxy)silanes is readily cleaved by hydrogen peroxyde to form the corresponding aldehydes, carboxylic acids or ketones, depending upon the nature of the alkenyl group and the reaction conditions.
- Tamao, Kohei,Kumada, Makoto,Maeda, Kimio
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p. 321 - 324
(2007/10/02)
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- Alkylation of vinylidene chloride and vinylidene bromide
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Vinylidene chloride and vinylidene bromide are alkylated by reaction with alkylating agents such as selected olefins, tert-alkyl halides, and secondary or tertiary alcohols in a reaction medium comprising trifluoromethane-sulfonic acid. In specific embodiments, the reaction medium can additionally comprise water, methanol, and BF3.
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