Showing papers on "Benzaldehyde published in 1987"
TL;DR: In this paper, a new type of iron catalyzed insertion of isonitrile into the C-H bond of arenes to produce aldimines was reported, which is the first successful metal-based alkane functionalization.
Abstract: Many examples of the activation of aromatic and aliphatic carbon-hydrogen bonds by homogeneous transition-metal complexes have appeared over the past few years, offering attractive new routes to organometallic species. While several of these reports involve oxidative addition of low valent metal complexes to alkanes or arenes, these new adducts have not proven to be useful for the generation of functionalized hydrocarbon products. Reports of successful metal-based alkane functionalization include free radical oxidations, intramolecular cyclizations of alkyl carbenoid species to given cyclopentanones, aromatic isonitrile insertion to give indoles, and alkane dehydrogenation to produce olefins. Arene functionalization reactions commonly depend upon the presence of tethering groups, although the production of benzaldehyde, benzoic acid, styrene, and phenylsiloxane insertion products have been recently reported. They report here a new type of iron catalyzed insertion of isonitrile into the C-H bond of arenes to produce aldimines (eq 1). RNC + C/sub 6/H/sub 6/ (Fe) ..-->.. ..delta..G/sup 0/ approx. = -11 Kcal/mol C/sub 6/H/sub 5/ - CH = NR (1).
88 citations
TL;DR: Allyltrifluorosilane/CsF systems form pentacoordinate allylsiliconates which undergo chemoselective, regiospecific and highly stereoselectively allylation of aldehydes, presumably via six-membered cyclic transition states as mentioned in this paper.
86 citations
TL;DR: In the presence of ephedrine and its derivatives, an optical yield of up to 80% is obtained for reaction at room temperature without special precautions as mentioned in this paper. But this is not the case for benzaldehyde derivatives.
69 citations
TL;DR: In this article, the authors presented methods by which enantiomerically pure 3-aminobutanoic acid derivatives can be prepared by adding dilithiated methyl- or ethyl-N-benzoyl-3aminobutoanoates to benzaldehyde to give products of l - and u, u -configuration respectively.
62 citations
TL;DR: In this paper, a surprising effect of temperature on enantiomeric excess in the stereospecific addition of diethylzinc to benzaldehyde with alkaloids as catalysts is reported.
56 citations
55 citations
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46 citations
TL;DR: Lewis acid-catalyzed, hetero Diels-Alder reaction of (E)-1-methoxy-3-trimethylsilyloxy-1,3-butadiene with 6-benzoyloxymethyl-2,4-dibenzyloxy benzaldehyde afforded 2-dihydro-4H- pyran-4-one.
45 citations
TL;DR: Cis -1,3-disubstituted tetrahydro-β-carbolines can be formed with high stereo and enantio-selectivity by conducting the Pictet-Spengler reaction at low temperature as mentioned in this paper.
45 citations
TL;DR: In this article, an unexpected behavior of the reaction of allylsilanes and carbonylcompounds allowed the stereospecific preparation of differently substituted 4-halotetrahydropyrans with an all cis configuration.
TL;DR: Chlorodifluoromethyl ketones efficiently underwent the aldol reaction with a variety of aldehydes or ketones in the presence of zinc, a catalytic amount of copper(I) chloride or silver (I) acetate and molecular sieves to give the corresponding α,α-difluoro-β-hydroxy ketones as mentioned in this paper.
TL;DR: The title compounds, readily prepared from allytrimethoxysilane, pyrocatechol, and triethylamine, react with aldehydes regiospecifically and chemoselectively without catalyst under mild conditions as discussed by the authors.
Abstract: The title compounds, readily prepared from allytrimethoxysilane, pyrocatechol, and triethylamine, react with aldehydes regiospecifically and chemoselectively without catalyst under mild conditions: the allylation takes place even in protic solvents such as ethanol.
TL;DR: In this article, the selectivity of benzaldehyde was very high in both the anodic and cathodic reactions, and the maximum total current efficiency for benzaldehyde production in the paired electrooxidation was 171%.
Abstract: Oxidation of toluene to benzaldehyde by Mn3+ and OH free radicals, generated in the anodic and cathodic reactions respectively, was carried out simultaneously in the cathodic and anodic compartments of a cell. The selectivity of benzaldehyde was very high in both the anodic and cathodic reactions. The maximum total current efficiency for benzaldehyde production in the paired electrooxidation was 171%.
TL;DR: In this paper, the preparation of t-butyl 4-diethylphosphono-3-oxobutanethioate and Wadsworth-Emmons reaction with aldehydes and ketones is reported.
TL;DR: A high turnover number was achieved in photo assisted carbonylation of C-H bonds of benzene catalyzed by RhCl(CO)(PMe3)2 under mild conditions (1 atm, 37 °C) to give mainly benzaldehyde.
Abstract: A high turnover number was achieved in the photo-assisted carbonylation of C–H bonds of benzene catalyzed by RhCl(CO)(PMe3)2 under mild conditions (1 atm, 37 °C) to give mainly benzaldehyde. Cyclohexane could also be carbonylated under the same conditions.
TL;DR: The photochemical behavior of long chain benzoin alkyl ethers when complexed to CCL has been investigated with the view to understand their chemical behavior when included in the above host matrix.
Abstract: The photochemical behavior of long chain benzoin alkyl ethers when complexed to $\beta$-cyclodextrin has been investigated with the view to understand their chemical behavior when included in the above host matrix. Photolysis results in benzil and pinacol ethers as the main products in solid $beta$-cyclodextrin complex and benzaldehyde, benzil, pinacol ethers, and deoxybenzoin in aqueous $\beta$-cyclodextrin complex. The results on long chain benzoin alkyl ethers 4-6 are distinctly different from those of short chain benzoin alkyl ethers 1-3.
TL;DR: Quaternary ammonium salts assist the extraction of both hydrogen peroxide and metal salts, e.g. ruthenium or palladium chloride from the aqueous to the non-aqueous component of a two-phase system.
Abstract: Quaternary ammonium salts assist the extraction of both hydrogen peroxide and metal salts, e.g. ruthenium or palladium chloride from the aqueous to the non-aqueous component of a two-phase system; the system has been used for the oxidation of styrene.
TL;DR: In this article, the treatment of methyl 3-phenylsulphonyl orthopropionate with n-BuLi gives the corresponding carbanion which reacts with aldehydes or ketones to yield β-pnsulphonicl γ-lactones.
TL;DR: In this article, a mechanistic model is proposed in which the reaction alternates between two stages, in stage I the dissolved oxygen concentration is appreciable and benzoyl radicals combine with oxygen, ultimately oxidizing Co(II) to Co(III).
Abstract: The oxidation of benzaldehyde catalyzed by cobalt and bromine is an oscillating reaction in which the concentrations of Co(III) and of dissolved oxygen vary periodically with time. A mechanistic model is proposed in which the reaction alternates between two stages. In stage I the dissolved oxygen concentration is appreciable and benzoyl radicals combine with oxygen, ultimately oxidizing Co(II) to Co(III). In stage II dissolved oxygen is depleted, and benzoyl radicals are oxidized by Co(III). The model gives satisfactory agreement with a number of qualitative and quantitative features. These include the composition of the steady states and the amplitude and period of oscillation for different concentrations of cobalt, bromide, and benzaldehyde. Specific measurements were also made of the kinetics of the reduction of cobalt(III) by mixtures of benzaldehyde and sodium bromide, the stability of a cobalt-bromide complex, and the consumption of /sup 18/O/sub 2/. This last study demonstrates the presence of two major pathways to benzoic acid which differ in the source of oxygen.
TL;DR: In this article, theacetalisation is realized by traitement des composes carbonyles par les alcools, dans l'acetonitrile anhydre, en presence du complexe poly(diphenylphosphinostyrene), iode comme catalyseur
Abstract: L'acetalisation est realisee par traitement des composes carbonyles par les alcools, dans l'acetonitrile anhydre, en presence du complexe poly(diphenylphosphinostyrene), iode comme catalyseur
TL;DR: In this paper, the activation of toluene, p-methoxytoluene and p-terbutyltolluene has been examined on several mixed oxide systems, based on molybdates, telluromolybdate and vanadia-titania catalysts.
TL;DR: This thesis is concerned with the purification and characterisation of these two NAD+-dependent, soluble enzymes, benzyl alcohol dehydrogenase and benzaldehyde dehydrogen enzyme II.
Abstract: 1. Acinetobacter calcoaceticus NCIB 8250 can grow on benzyl alcohol as sole source of carbon and energy. Previous work had shown that benzyl alcohol is oxidised to benzoate by benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase II. This thesis is concerned with the purification and characterisation of these two NAD+-dependent, soluble enzymes.
TL;DR: In this paper, anisole, benzaldehyde, and acide benzoique sur TiO 2 and sur la silice have been investigated in the context of spectrometrie IR.
Abstract: Etude, par spectrometrie IR, de l'adsorption du phenol, de l'anisole, du benzaldehyde et de l'acide benzoique sur TiO 2 et sur la silice
TL;DR: Mn2+ catalyzes the aerobic oxidation of phenylpyruvic acid and appears to favour the dioxetane route, while the relative importance of these routes in biological systems is discussed.
TL;DR: In this article, asymmetric addition of arylmagnesium bromides to aldehydes provided corresponding carbinols in 40-75% ee, using chiral diamine ligands.
Abstract: Utilizing novel chiral diamine ligands, asymmetric addition of arylmagnesium bromides to aldehydes provided the corresponding carbinols in 40–75% ee.