- An Unexpected “Step-Conjugated” Biphosphole via Unique P–P Bond Formation
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The synthesis of a π-conjugated organophosphorus species with bridging P–P unit is reported. Because of the pyramidal geometry of the phosphorus centers, the molecular scaffold provides intriguing electronic communication throughout the three-dimensional structure via π-σ-π conjugation in stepwise fashion. The dimeric species was serendipitously found to be accessible via a reaction of the corresponding P-amino-phosphole precursor through mediation with the hard Lewis acid BF3. We provide detailed mechanistic studies toward a suitable reaction mechanism that was also verified via computational means. Moreover, we elaborate the utility of the biphosphole via phosphorus functionalization that lends further proof for the step conjugation provided by the unique phosphorus-based molecular architecture. Fundamental chemistry lays the foundation for future innovation with considerable impact on next-generation technologies. Main-group chemistry in particular provides a unique angle with regard to structure and bonding, which makes it an intriguing state-of-the-art avenue for the development of readily accessible advanced materials with significantly value-added functionality, that is, optical and electronic properties. The need for innovative molecular architectures is particularly evident in the rapidly accelerating development of conjugated organic building blocks because their high utility for a variety of sustainable energy applications is now well established. Herein, we report a unique type of phosphorus-based “step-conjugated” building block via an unexpected reaction that we have elucidated mechanistically in our studies. Reaction of a P-amino-dithienophosphole with the hard Lewis acid, BF3, leads to a dimeric species via a P–P bond-forming reaction, as supported through systematic mechanistic studies. Because of the inherent pyramidal geometry of the phosphorus centers, the dimer shows extended step-like conjugation through the scaffold via π-σ-π conjugation, which makes it an intriguing new building block for organic hybrid materials.
- Wang, Zisu,Asok, Nayanthara,Gaffen, Joshua,Gottlieb, Yael,Bi, Wenhua,Gendy, Chris,Dobrovetsky, Roman,Baumgartner, Thomas
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- Isolation and stabilization of a pheromone in crystalline molecular capsules
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The active monomer form of the male-produced pheromone of the Mediterranean fruit fly can be isolated selectively from its equilibrating trimer species by encapsulation within a calixarene pocket built into a hydrogen-bonded framework from guanidinium 4-sulfocalix[4]arene. Encapsulation of the Δ1- pyrroline guest significantly perturbs the assembly of the quasihexagonal two-dimensional guanidinium-sulfonate network of the guest-free framework, to the extent that guanidinium ions are excluded from some sites to accommodate the steric requirements of the guest. Nonetheless, single crystal X-ray diffraction reveals the preservation of a layered structrure in which the calixarene capsules stack in an antiparallel configuration. These observations illustrate that the binding of the pheromone monomer by the calixarene is sufficiently strong to overcome the loss of guanidinium-sulfonate hydrogen bonds, which is corroborated by the strong binding constants measured in solution. The solid-state encapsulation stabilizes the otherwise volatile unstable monomer form, suggesting an effective strategy for the storage, application, and controlled release of an important agricultural adjuvant.
- Xiao, Wenchang,Hu, Chunhua,Ward, Michael D.
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- Photoextrusion of molecular nitrogen from annulated 5-alkylidene-4,5-dihydro-1H-tetrazoles: Annulated iminoaziridines and the first triplet diazatrimethylenemethane
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Deprotonation of the annulated tetrazolium salts 4, 6, 8, 10, and 12 with sodium or potassium hydride yields the alkyh'denedihydrotetrazoles 5, 7, 9, 11, and 13, respectively. While 5a and b are unstable, even in solution at low temperatures, 7, 9, 11, and 13 form yellow oils that are distilled under high vacuum. - Irradiation of solutions of 7, 9, and 11 in [D8]toluene at -60°C yields, besides molecular nitrogen, annulated iminoaziridines that have an exocyclic CN double bond, i.e. 14, 16, and 18, respectively. In addition, an equal amount of the isomer 19 with the endocyclic CN double bond is formed from 11. On thermolysis, 14, 16, and 18 undergo [2 + 1] cycloreversion into methyl isocyanide and the cyclic imines 15, 17, and 20, respectively. By contrast, 19 rearranges thermally to yield 18. While the doubly bridged alkylidenedihydrotetrazole 13a affords only unidentified decomposition products on photolysis, its methyl homologue 13b is converted into the hexahydronaphthyridine 22 which is also formed on thermolysis. - Irradiation of 13b in a 2-methyltetrahydrofuran or butyronitrile matrix at 77 K yields a triplet diradical showing a four-line EPR spectrum centred at 3362 G and a half-field transition (at 1669 G) with a hyperfine structure. The zero-field splitting parameters |D/hc| = 0.031 cm-1 and |E/hc| = 0.0014 cm-1 are obtained by simulation of the EPR spectrum. The signal-carrier is assigned the diazatrimethylenemethane structure 23 on the basis of the close similarity between its EPR spectrum and those of trimethylenemethane (28) and tris(N-methylimino)methane (29). - Structural features are discussed that are responsible for the observed differences between the photochemical pathways.
- Quast, Helmut,Fuss, Andreas,Nuedling, Wolfgang
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- OXIDATIVE SPALTUNG VON 2-(PYRROLIDINOMETHYL)PYRIDIN-1-OXID MIT ANSCHLIESSENDER REKOMBINATION UND DIE KRISTALLSTRUKTUR VON (E)-2-(1-PYRROLIN-3-YLIDENMETHYL)PYRIDIN-1-OXID
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Mercury EDTA dehydrogenation of 2-(pyrrolidinomethyl)-pyridine-1-oxide (1) yields the pyrrolidone 5, which may be accounted for by a neighbouring effect of the amine oxide group.For an additional basic product the structure of (E)-2-(1-pyrroline-3-ylidenemethyl)-pyridine-1-oxide (11) has been proved by X-ray crystallography and synthesis.This indicates a cleavage of the doubly dehydrogenated product followed by recombination.
- Moehrle, H.,Troester, G.,Linden, M.,Mootz, D.,Wunderlich, H.
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- CHARACTERIZATION OF MAIZE POLYAMINE OXIDASE
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Some structural and biochemical characteristics of polyamine oxidase (PAO) purified from maize shoots have been examined.The enzyme has only alanine as N-terminal amino acid and its N-terminal sequence shows a significant degree of homology with tryptophan 2-monooxygenase from Pseudomonas syringae pv. savastanoi.The pH optimum for the stability of the native enzyme is 5, similar to that of the barley leaf enzyme.Calorimetric analysis shows a single two-state transition at pH 6 with Tm 49.8 deg.At pH 5 the thermal stability is increased by more than 14 deg.Amine oxidation products, Δ1-pyrroline and diazabicyclononane, are competitive inhibitors of PAO activity (apparent Ki = 400 and 100 μM respectively).Moreover these compounds improve the thermal stability of the enzyme.N1-Acetylspermine, which is a good substrate for mammalian PAO, acts as a non-competitive inhibitor for the plant enzyme.
- Federico, Rodolfo,Cona, Alessandra,Angelini, Riccardo,Schinina, M. Eugenia,Giartosio, Anna
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- Structural equilibrium and ring-chain tautomerism of aqueous solutions of 4-aminobutyraldehyde
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NMR spectroscopy of aqueous solutions of 4-aminobutyraldehyde in the range 0 pH 13 established the occurrence of protonated and hydrated amino aldehydes in equilibrium with pyrrolines, and pyrrolinium salts.
- Struve, Casper,Christophersen, Carsten
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- Mexican fruit fly attractants: Effects of 1-pyrroline and other amines on attractiveness of a mixture of ammonia, methylamine, and putrescine
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Several amines were tested alone and in combination with AMPu, an attractant mixture containing ammonium bicarbonate or ammonium carbonate, methylamine hydrochloride, and putrescine, for attractiveness to Mexican fruit flies (Anastrepha ludens Loew). In laboratory bioassay, 1-pyrroline, 3-pyrroline, 2-(methylamino)ethanol, spermidine, spermine, and indole-3-acetic acid were significantly more attractive than solvent controls. In orchard tests, traps bailed with combinations of AMPu with dimethylamine hydrochloride, ethylamine, 2,5-dimethylpyrazine, or pyrrolidine captured fewer flies than traps baited with AMPu alone. Traps containing AMPu plus additional ammonium bicarbonate were much less attractive than AMPu alone. Combinations of AMPu with 1-pyrroline were about 50% more attractive than AMPu alone to both males and females. Combinations of AMPu with 3-pyrroline were not significantly more attractive than AMPu alone.
- Robacker,Demilo,Voaden
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- A rapid synthesis of racemic brevioxime
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Racemic brevioxime has been synthesised starting from N-propionyl-2-pyrroline by intramolecular cyclisation of a β-ketoamide using nitrosyl chloride.
- Parsons,Karadogan,Macritchie
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- Diversification of Unprotected Alicyclic Amines by C?H Bond Functionalization: Decarboxylative Alkylation of Transient Imines
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Despite extensive efforts by many practitioners in the field, methods for the direct α-C?H bond functionalization of unprotected alicyclic amines remain rare. A new advance in this area utilizes N-lithiated alicyclic amines. These readily accessible intermediates are converted to transient imines through the action of a simple ketone oxidant, followed by alkylation with a β-ketoacid under mild conditions to provide valuable β-amino ketones with unprecedented ease. Regioselective α′-alkylation is achieved for substrates with existing α-substituents. The method is further applicable to the convenient one-pot synthesis of polycyclic dihydroquinolones through the incorporation of a SNAr step.
- Paul, Anirudra,Kim, Jae Hyun,Daniel, Scott D.,Seidel, Daniel
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supporting information
p. 1625 - 1628
(2020/11/30)
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- α-C-H Bond Functionalization of Unprotected Alicyclic Amines: Lewis-Acid-Promoted Addition of Enolates to Transient Imines
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Enolizable cyclic imines, obtained in situ from their corresponding lithium amides by oxidation with simple ketone oxidants, are readily alkylated with a range of enolates to provide mono- and polycyclic β-aminoketones in a single operation, including the natural product (±)-myrtine. Nitrile anions also serve as competent nucleophiles in these transformations, which are promoted by BF3 etherate. β-Aminoesters derived from ester enolates can be converted to the corresponding β-lactams.
- Kim, Jae Hyun,Paul, Anirudra,Ghiviriga, Ion,Seidel, Daniel
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supporting information
p. 797 - 801
(2021/02/06)
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- α-C-H/N-H Annulation of Alicyclic Amines via Transient Imines: Preparation of Polycyclic Lactams
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Polycyclic lactams are prepared in a single operation from o-toluamides and cyclic amines in a process that involves transient cyclic imines, species that are conveniently obtained in situ from the corresponding lithium amides and simple ketone oxidants. Imines thus generated, such as 1-pyrroline and 1-piperideine, engage lithiated o-toluamides in a facile annulation process. Undesired side reactions such as imine deprotonation and o-toluamide dimerization are suppressed through the judicious choice of reaction conditions.
- Chen, Weijie,Seidel, Daniel
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supporting information
p. 3729 - 3734
(2021/05/31)
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- α,α′-C-H Bond Difunctionalization of Unprotected Alicyclic Amines
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A simple one-pot procedure enables the sequential, regioselective, and diastereoselective introduction of the same or two different substituents to the α- and α′-positions of unprotected azacycles. Aryl, alkyl, and alkenyl substituents are introduced via their corresponding organolithium compounds. The scope of this transformation includes pyrrolidines, piperidines, azepanes, and piperazines.
- Valles, Daniel A.,Dutta, Subhradeep,Paul, Anirudra,Abboud, Khalil A.,Ghiviriga, Ion,Seidel, Daniel
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supporting information
p. 6367 - 6371
(2021/08/18)
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- Green oxidation of amines by a novel cold-adapted monoamine oxidase mao p3 from psychrophilic fungi pseudogymnoascus sp. p3
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The use of monoamine oxidases (MAOs) in amine oxidation is a great example of how biocatalysis can be applied in the agricultural or pharmaceutical industry and manufacturing of fine chemicals to make a shift from traditional chemical synthesis towards more sustainable green chemistry. This article reports the screening of fourteen Antarctic fungi strains for MAO activity and the discovery of a novel psychrozyme MAOP3 isolated from the Pseudogymnoascus sp. P3. The activity of the native enzyme was 1350 ± 10.5 U/L towards a primary (n-butylamine) amine, and 1470 ± 10.6 U/L towards a secondary (6,6-dimethyl-3-azabicyclohexane) amine. MAO P3 has the potential for applications in biotransformations due to its wide substrate specificity (aliphatic and cyclic amines, pyrrolidine derivatives). The psychrozyme operates at an optimal temperature of 30? C, retains 75% of activity at 20? C, and is rather thermolabile, which is beneficial for a reduction in the overall costs of a bioprocess and offers a convenient way of heat inactivation. The reported biocatalyst is the first psychrophilic MAO; its unique biochemical properties, substrate specificity, and effectiveness predispose MAO P3 for use in environmentally friendly, low-emission biotransformations.
- Bia?kowska, Aneta M.,Jod?owska, Iga,Szymczak, Kamil,Twarda-Clapa, Aleksandra
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supporting information
(2021/10/25)
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- Mechanistically Guided Design of an Efficient and Enantioselective Aminocatalytic α-Chlorination of Aldehydes
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The enantioselective aminocatalytic α-chlorination of aldehydes is a challenging reaction because of its tendency to proceed through neutral intermediates in unselective pathways. Herein we report the rational shift to a highly selective reaction pathway involving charged intermediates using hexafluoroisopropanol as solvent. This change in mechanism has enabled us to match and improve upon the yields and enantioselectivities displayed by previous methods while using cheaper aminocatalysts and chlorinating agents, 80-95% less amount of catalyst, convenient temperatures, and shorter reaction times.
- Hutchinson, George,Alamillo-Ferrer, Carla,Burés, Jordi
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supporting information
p. 6805 - 6809
(2021/05/29)
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- Enantioselective Reductive Coupling of Imines Templated by Chiral Diboron
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We herein report a general, practical, and highly efficient method for asymmetric synthesis of a wide range of chiral vicinal diamines via reductive coupling of imines templated by chiral diboron. The protocol features high enantioselectivity and stereospecificity, mild reaction conditions, simple operating procedures, use of readily available starting materials, and a broad substrate scope. The method signifies the generality of diboron-enabled [3,3]-sigmatropic rearrangement.
- Chen, Dongping,Li, Kaidi,Tang, Wenjun,Xu, Guangqing,Xu, Ronghua,Zhou, Mingkang
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supporting information
p. 10337 - 10342
(2020/07/04)
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- Synthesis and application of novel s-guaiazulene sesquiterpenoid alkaloids
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The invention belongs to the field of synthetic pharmacochemistry and particularly relates to chemical synthesis and an application of a new framework of s-guaiazulene sesquiterpenoid alkaloids from Muriceides collaris. Muriceidine A is successfully designed and synthesized from s-guaiazulene and piperidine acid as raw materials with a chemical method. In order to verify the universality of the synthesis method, azulene aldehyde is linked with piperidine, methylpiperidine, pyrrole, piperidinemethanol, 4-hydroxypiperidine and other N-heterocycle fragments. Screening of antitumor activity in vitro finds that the IC50 values of structure optimized products 2 and 3 for 14 tumor cell strains including 231, MCF-7, K562, HCT-116, Hela, A549, H1975, HUVEC, MGC-803, SH-SY5Y, HO8910, Siha, PC-3 andBEL7402 are smaller than 10 mu M, and therefore, the new framework of s-guaiazulene sesquiterpenoid alkaloids can be used for research and development of antitumor drugs.
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Paragraph 0084; 0085
(2019/08/06)
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- α-Functionalization of Cyclic Secondary Amines: Lewis Acid Promoted Addition of Organometallics to Transient Imines
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Cyclic imines, generated in situ from their corresponding N-lithiated amines and a ketone hydride acceptor, undergo reactions with a range of organometallic nucleophiles to generate α-functionalized amines in a single operation. Activation of the transient imines by Lewis acids that are compatible with the presence of lithium alkoxides was found to be crucial to accommodate a broad range of nucleophiles including lithium acetylides, Grignard reagents, and aryllithiums with attenuated reactivities.
- Paul, Anirudra,Seidel, Daniel
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supporting information
p. 8778 - 8782
(2019/06/07)
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- Preparation method of 2-(2,5-difluorophenyl) pyrrolidine
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The invention provides a preparation method of 2-(2,5-difluorophenyl) pyrrolidine. The preparation method comprises the following steps: (1) tetrahydropyrrole reacts with N-chlorosuccinimide to generate 1-chloropyrrolidine; (2) the 1-chloropyrrolidine generated in the step (1) carries out elimination reaction in sodium methylate solution to generate 3,4-dihydro-2H-pyrrole; (3) the 3,4-dihydro-2H-pyrrole generated in the step (2) reacts with a 2,5-difluorobromobenzene Grignard reagent to obtain the 2-(2,5-difluorophenyl) pyrrolidine. The preparation method of the 2-(2,5-difluorophenyl) pyrrolidine provided by the invention has the beneficial effects that the synthetic process is reasonably designed, the reagent is cheap, the purchase is convenient, no heavy metal pollution is caused, the reaction conditions are mild, the cost of raw materials is low, no special equipment is needed, the operation is simple and convenient, and the energy consumption is low, so that the preparation methodis sutiable for industrial production.
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Paragraph 0037; 0040
(2018/07/30)
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- One-Pot Tandem Photoredox and Cross-Coupling Catalysis with a Single Palladium Carbodicarbene Complex
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The combination of conventional transition-metal-catalyzed coupling (2 e? process) and photoredox catalysis (1 e? process) has emerged as a powerful approach to catalyze difficult cross-coupling reactions under mild reaction conditions. Reported is a palladium carbodicarbene (CDC) complex that mediates both a Suzuki–Miyaura coupling and photoredox catalysis for C?N bond formation upon visible-light irradiation. These two catalytic pathways can be combined to promote both conventional transition-metal-catalyzed coupling and photoredox catalysis to mediate C?H arylation under ambient conditions with a single catalyst in an efficient one-pot process.
- Hsu, Yu-Cheng,Wang, Vincent C.-C.,Au-Yeung, Ka-Chun,Tsai, Chung-Yu,Chang, Chun-Chi,Lin, Bo-Chao,Chan, Yi-Tsu,Hsu, Chao-Ping,Yap, Glenn P. A.,Jurca, Titel,Ong, Tiow-Gan
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supporting information
p. 4622 - 4626
(2018/03/21)
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- Copper-catalyzed direct oxidative α-arylation of pyrrolidine with phenols and naphtols
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An efficient procedure for the direct arylation of pyrrolidine with phenols and naphtols is reported. Upon reaction with catalytic amounts of a binuclear copper(II)-7-azaindole complex under an atmosphere of oxygen, pyrrolidine is smoothly oxidized to the corresponding imine which can be trapped in situ by a series of phenols and naphtols in fair to good yields. This copper-catalyzed direct oxidative arylation of pyrrolidine offers an efficient entry to α-aryl-pyrrolidines in a single step and without the need for protecting or directing groups.
- Gérard, Phidéline,Evano, Gwilherm
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supporting information
p. 359 - 364
(2018/05/22)
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- Unusual activation pathways of amines in the reactions with molybdenum pentachloride
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The 1-:-1 molar reactions at room temperature of MoCl5 with aliphatic amines were investigated in dichloromethane. Pyrrolidine, diethylamine and dibenzylamine underwent dehydrogenative oxidation when allowed to react with MoCl5; the compounds [MoCl5{NCH(CH2)3}], 1, and [CH3CHNHEt][MoOCl4], 2, were isolated in moderate to low yields from MoCl5/pyrrolidine and MoCl5/NHEt2, respectively. The chloride-amide complex [MoCl4(NEt2)], 3, was afforded in 65% yield from MoCl5 and Et2NSiMe3. The interaction of MoCl5 with Me2NSiMe3 was accompanied by activation of the solvent, and the complexes [MoCl3(NMe2)(κ2-Me2NCH2NMe2)], 4a, and [MoCl3(NMe)(κ2-Me2NCH2NMe2)], 4b, co-crystallized from the reaction mixture. The reactions of MoCl5 with a series of primary amines afforded mixtures of products, and the Mo(vi) chloride imido complexes [MoCl4(NR)]2 (R = Cy, 5a; tBu, 5b) were isolated in ca. 40% yield from MoCl5/NH2R (R = Cy, tBu). C-H bond activation may be viable in the reactions of MoCl5 with tertiary amines: the compounds [(CH2Ph)2NCHPh]2[MoCl6]·CH2Cl2, 6, and [NHEt3]2[Mo2Cl10], 7, were obtained from MoCl5/tribenzylamine and MoCl5/triethylamine, respectively. Pyrrolidine and tribenzylamine underwent analogous activation pathways when allowed to react with [MoCl3{OCH(CF3)2}]2 in the place of MoCl5. The isolated metal products were characterized by analytical and spectroscopic techniques, in addition the structures of 1, 2, 4, 5a, 6·CH2Cl2 and 7 were ascertained by single crystal X-ray diffraction studies. The organic products were identified by NMR and GC-MS after hydrolysis of the reaction mixtures. DFT calculations were carried out in order to assist the IR assignments, and clarify structural and mechanistic aspects.
- Bartalucci, Niccolò,Bortoluzzi, Marco,Marchetti, Fabio,Pampaloni, Guido,Schoch, Silvia,Zacchini, Stefano
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p. 4329 - 4340
(2017/07/10)
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- Biocatalytic transamination with near-stoichiometric inexpensive amine donors mediated by bifunctional mono- and di-amine transaminases
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The discovery and characterisation of enzymes with both monoamine and diamine transaminase activity is reported, allowing conversion of a wide range of target ketone substrates with just a small excess of amine donor. The diamine co-substrates (putrescine, cadaverine or spermidine) are bio-derived and the enzyme system results in very little waste, making it a greener strategy for the production of valuable amine fine chemicals and pharmaceuticals.
- Galman, James L.,Slabu, Iustina,Weise, Nicholas J.,Iglesias, Cesar,Parmeggiani, Fabio,Lloyd, Richard C.,Turner, Nicholas J.
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supporting information
p. 361 - 366
(2017/08/14)
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- α-Amino Acid-Isosteric α-Amino Tetrazoles
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The synthesis of all 20 common natural proteinogenic and 4 otherα-amino acid-isosteric α-amino tetrazoles has been accomplished, whereby the carboxyl group is replaced by the isosteric 5-tetrazolyl group. The short process involves the use of the key Ugi tetrazole reaction followed by deprotection chemistries. The tetrazole group is bioisosteric to the carboxylic acid and is widely used in medicinal chemistry and drug design. Surprisingly, several of the common α-amino acid-isosteric α-amino tetrazoles are unknown up to now. Therefore a rapid synthetic access to this compound class and non-natural derivatives is of high interest to advance the field.
- Zhao, Ting,Kurpiewska, Katarzyna,Kalinowska-T?us?cik, Justyna,Herdtweck, Eberhardt,D?mling, Alexander
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supporting information
p. 3009 - 3018
(2016/03/26)
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- PdPb-Catalyzed decarboxylation of proline to pyrrolidine: Highly selective formation of a biobased amine in water
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Amino acids have huge potential as platform chemicals in the biobased industry. Pd-catalyzed decarboxylation is a very promising route for the valorization of these natural compounds derived from protein waste or fermentation. We report that the highly abundant and nonessential amino acid L-proline is very reactive in the Pd-catalyzed decarboxylation. Full conversions are obtained with Pd/C and different Pd/MeOx catalysts; this allowed the identification of the different side reactions and the mapping of the reaction network. Due to the high reactivity of pyrrolidine, the selectivity for pyrrolidine was initially low. By carefully modifying Pd/ZrO2 with Pb in a controlled mannervia two incipient wetness impregnation stepsthe selectivity increased remarkably. Finally, a thorough investigation of the reaction parameters resulted in an increased activity of this modified catalyst and an even further enhanced selectivity under a low H2 pressure of 4 bar at 235 °C in water. This results in a very selective and sustainable production route for the highly interesting pyrrolidine.
- Verduyckt, Jasper,Van Hoof, Maarten,De Schouwer, Free,Wolberg, Marike,Kurttepeli, Mert,Eloy, Pierre,Gaigneaux, Eric M.,Bals, Sara,Kirschhock, Christine E.A.,De Vos, Dirk E.
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p. 7303 - 7310
(2018/05/23)
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- mellow amination by homogeneous catalysis of the method for the production of primary amines
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The invention relates to a method for producing primary amines by means of the alcohol amination of alcohols with ammonia, with water being eliminated. The method comprises the steps of: (a) a homogenously-catalysed reaction of a reaction mixture which contains at least one alcohol, ammonia, at least one non-polar solvent, and at least one catalyst containing at least one element selected from groups 8, 9 and 10 of the periodic table in the liquid phase, a product mixture (P) thus being obtained; (b) separating the phases of product mixture (P) which was obtained in step (a), if necessary after a reduction in temperature, a reduction in pressure and/or the addition of at least one polar solvent with a miscibility gap in relation to the non-polar solvent, and thus obtaining at least one polar product phase (A) and at least one non-polar phase (B) containing at least one portion of the catalyst that was introduced, with said non-polar phase (B) being separated off, (c) returning at least one portion of the non-polar phase (B) into the reaction in step (a), and (d) separating the amination product from the polar product phase (A). The non-polar solvent introduced in (a) and the catalyst introduced in step (a) are selected such that the catalyst in the non-polar phase (B) becomes enriched.
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Paragraph 0265; 0266
(2016/10/09)
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- METHOD FOR PRODUCING ALKANOL AMINES BY HOMOGENEOUSLY CATALYZED ALCOHOL AMINATION
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PROBLEM TO BE SOLVED: To provide a method for producing alkanol amines by alcohol amination of diols using ammonia under elimination of water. SOLUTION: The invention relates to a method for producing alkanol amines which comprise a primary amino group (-NH2) and a hydroxyl group (-OH), by alcohol amination of diols comprising two hydroxyl groups (-OH) using ammonia under elimination of water. The reaction is homogeneously catalyzed in the presence of at least one complex catalyst which contains at least one element selected from groups 8, 9 and 10 of the periodic table and at least one donor ligand. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0088; 0095
(2016/10/27)
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- The preparation obtained by homogeneous catalysis mellow amination method of the primary amine
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The invention relates to a method for producing primary amines comprising at least one functional group of formula (-CH2-NH2), by alcohol amination of educts which comprise at least one functional group of formula (-CH2-OH), using ammonia, and elimination of water. The homogeneously catalyzed alcohol amination is carried out in the presence of at least one complex catalyst which contains at least one element selected from the groups 8 and 9 of the periodic table and at least one phosphorus donor ligand of general formula (I).
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Paragraph 0207-0208; 0212
(2017/02/28)
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- Galactose Oxidase Variants for the Oxidation of Amino Alcohols in Enzyme Cascade Synthesis
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The use of selected engineered galactose oxidase (GOase) variants for the oxidation of amino alcohols to aldehydes under mild conditions in aqueous systems is reported. GOase variant F2 catalyses the regioselective oxidation of N-carbobenzyloxy (Cbz)-protected 3-amino-1,2-propanediol to the corresponding α-hydroxyaldehyde which was then used in an aldolase reaction. Another variant, M3-5, was found to exhibit activity towards free and N-Cbz-protected aliphatic and aromatic amino alcohols allowing the synthesis of lactams such as 3,4-dihydronaphthalen-1(2H)-one, 2-pyrrolidone and valerolactam in one-pot tandem reactions with xanthine dehydrogenase (XDH) or aldehyde oxidase (PaoABC).
- Herter, Susanne,McKenna, Shane M.,Frazer, Andrew R.,Leimkühler, Silke,Carnell, Andrew J.,Turner, Nicholas J.
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p. 2313 - 2317
(2015/08/11)
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- Mechanistic Investigations of the Catalytic Formation of Lactams from Amines and Water with Liberation of H2
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The mechanism of the unique lactam formation from amines and water with concomitant H2 liberation with no added oxidant, catalyzed by a well-defined acridine-based ruthenium pincer complex was investigated in detail by both experiment and DFT calculations. The results show that a dearomatized form of the initial complex is the active catalyst. Furthermore, reversible imine formation was shown to be part of the catalytic cycle. Water is not only the oxygen atom source but also acts as a cocatalyst for the H2 liberation, enabled by conformational flexibility of the acridine-based pincer ligand. (Figure Presented).
- Gellrich, Urs,Khusnutdinova, Julia R.,Leitus, Gregory M.,Milstein, David
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supporting information
p. 4851 - 4859
(2015/04/27)
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- · Uniform catalyst by using alcohol aminosilicone di-, tri-and a method of manufacturing a polyphenylenepolyamine
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The invention relates to a method for producing primary amines, which contain at least one functional group of the formula (-CH2-NH2) and at least one further primary amino group, by the alcohol amination of reactants, which contain at least one functional group of the formula (-CH2-OH) and at least one further functional group (-X), wherein (-X) is selected from hydroxyl groups and primary amino groups, using ammonia with removal of water, wherein the reaction is carried out in a homogeneously catalyzed manner in the presence of at least one complex catalyst containing at least one element selected from groups 8, 9 and 10 of the periodic table and at least one donor ligand.
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Page/Page column 0099; 0106; 0107
(2016/10/09)
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- Synthesis of N-aminopyrrolidine by the raschig process: Kinetic and mechanistic study of the monochloramine-pyrrolidine interaction
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1-Pyrrolidinamine (NAPY) belongs to a family of large compounds, namely the alkylhydrazines, used as precursors for different targets in fine chemicals, such as pharmaceuticals and cosmetics. Different synthetic methods are described in the literature; however, many of them are not adaptable on a large scale. The Raschig process appears to be the most relevant method for preparing hydrazines at the industrial scale: hydrazines are obtained by two successive reactions. The first involves the formation of monochloramine from sodium hypochlorite and excess ammonia. The second consists of reacting, in a basic medium, the monochloramine previously synthesized with excess amine to provide the corresponding hydrazine. It is a clean and selective method, distinguished by its nonpolluting aspect, its low cost, and the feasibility of continuous transposition to industrial scale. However, it presents some disadvantages linked to the low hydrazine concentrations in the synthesis solutions. The optimization of the synthesis parameters is therefore essential and requires a detailed kinetic and mechanistic study of the reaction of NAPY formation by the chloramine/pyrrolidine interaction. The kinetics of the NAPY formation reaction were studied in alkaline medium, at first at a temperature of 25°C. Excess pyrrolidine was used with respect to NH2Cl, in order to minimize the influence of side reactions. Owing to the high reaction rates, the essays were carried out in a dilute medium, using reagent concentrations ranging between 1 × 10-3 and 4 × 10-2 M. The ionic strength of the medium was established by NaOH concentration (0.1 M). Then, the influence of the temperature was studied between 15 and 45°C for NH2Cl and PY concentrations, respectively, equal to 2 × 10-3 and 0.01 M, in order to check the conformance to the Arrhenius law. Finally, the characterization of the reaction mixture permitted establishment of a global reaction scheme, including two main secondary reactions.
- Dhenain,Darwich,Frangieh,Goutal,Delalu
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p. 338 - 349
(2014/05/06)
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- Matrix-IR spectroscopic investigations of the thermolysis and photolysis of diazoamides
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Matrix photolysis of N,N-dialkyldiazoacetamides 1a-d at 7-10 K results in either the formation of C-H insertion products (in case of N,N-dimethyl and N,N-diethyl diazoamides) or almost exclusive Wolff rearrangement to ketenes (in the case of the cyclic di
- Wentrup, Curt,Bibas, Herve,Kuhn, Arvid,Mitschke, Ullrich,McMills, Mark C.
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p. 10705 - 10717
(2013/11/19)
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- PROCESS FOR THE PREPARATION OF PRIMARY AMINES BY HOMOGENEOUSLY CATALYZED ALCOHOL AMINATION
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Process for the preparation of primary amines which have at least one functional group of the formula (—CH2—NH2) by alcohol amination of starting materials which have at least one functional group of the formula (—CH2—OH), with ammonia, with the elimination of water, where the alcohol amination is carried out under homogeneous catalysis in the presence of at least one complex catalyst which comprises at least one element selected from groups 8 and 9 of the Periodic Table of the Elements, and also at least one phosphorus donor ligand of the general formula (I).
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Page/Page column 10-11
(2012/09/22)
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- PROCESS FOR PREPARING DI-, TRI- AND POLYAMINES BY HOMOGENEOUSLY CATALYZED ALCOHOL AMINATION
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Process for preparing primary amines which have at least one functional group of the formula (—CH2—NH2) and at least one further primary amino group by alcohol amination of starting materials having at least one functional group of the formula (—CH2—OH) and at least one further functional group (—X), where (—X) is selected from among hydroxyl groups and primary amino groups, by means of ammonia with elimination of water, wherein the reaction is carried out homogeneously catalyzed in the presence of at least one complex catalyst comprising at least one element selected from groups 8, 9 and 10 of the Periodic Table and also at least one donor ligand.
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Page/Page column 12; 13
(2012/09/22)
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- Oxidation of di- and polyamines: In vitro effect of amino aldehydes on the vitality of Leishmania promastigotes
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The aminoaldehydes 4-aminobutanal and 5-aminopentanal, derived from the oxidation of the diamines putrescine and cadaverine, and 1-(3-aminopropyl)-4- aminobutanal and aminodialdehyde, derived from the oxidation of the polyamines spermidine and spermine, were produced utilizing a copper amine oxidase (CAO) from Euphorbia characias latex and tested with in vitro cultivation of Leishmania infantum promastigotes. Whereas the aminoaldehydes derived from the oxidation of the diamines were stimulating factors for growth of Leishmania infantum promastigotes, the aldehydes derived from polyamines oxidation had a drastic inhibitory effect on the vitality and growth of these parasites. Thus, a double scenario arises, showing the use of aldehydes from diamines to obtain a large number of organisms of Leishmania infantum promastigotes to use in serological studies, whereas the aldehydes derived from polyamines could be used as a new strategy for therapeutic treatment against these parasites.
- Massa, Silvia,Spano, Delia,Pintus, Francesca,Medda, Rosaria,Floris, Giovanni
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scheme or table
p. 77 - 83
(2010/11/18)
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- Condensation of 2-alkylcyclohexane-1,3-diones with cyclic azomethines
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Reaction of 2-acylcyclohexane-1,3-diones with 5- and 6-membered cyclic azomethines (3,4-dihydro-2H-pyrrole and 2,3,4,5-tetrahydropyridine) furnished derivatives of 2,3,3a;,4,8,9-hexahydropyrrolo[1,2-a]quinoline-5,6(1H,5aH)-dione and 3,4,4a,5,9,10-hexahydro-1H-pyrido[1,2-a]quinoline-6,7(2H,8H)-dione respectively. In reaction with 7-membered 3,4,5,6-tetrahydro-2H-azepine we failed to isolate polycyclic nitrogen-containing products.
- Rubinova,Rubinova
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p. 1187 - 1189
(2007/10/03)
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- Reactions of N, N-dichloroalkylamines with solid base as studied by FTIR combined with DFT calculations
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Products of vacuum gas-solid reactions of N, N-dichloroalkylamines with KOH have been identified by FTIR spectroscopy and DFT calculations. It has been found that the reactions consist of elimination of two Cl atoms accompanied with migration of an H atom, a ring carbon or a methyl group from the α-carbon to the N atom and unstable imines with a C=N double bond are formed.
- Egawa,Ito,Konaka
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p. 337 - 344
(2007/10/03)
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- Nickel and nickel-magnesia catalysts active in the hydrogenation of 1,4-butanedinitrile
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Several NiO-MgO systems were synthesized to be studied as nickel catalysts for the hydrogenation of 1,4-butanedinitrile in the gas phase and compared with a bulk NiO of controlled morphology. All samples were characterized by XRD, BET, TPR, TPD, SEM, and H2 chemisorption techniques. The Ni-MgO systems had higher activities than the Ni bulk catalyst. The most active catalyst at all reaction temperatures was type R4CB which had homogeneous particles of about 1000 A, the highest metal surface area, and the highest coverage with weakly bound hydrogen. The presence of basic magnesia suppresses the condensation reactions and consequently favors the elimination of amines, and prevents catalyst deactivation. The selectivity toward the different products not only depends on the catalytic properties but can also be modified by controlling the hydrogen/dinitrile ratio. The highest selectivity to 4-aminobutanenitrile was achieved by catalyst R4CB, with 85% at 100% conversion and working at a space velocity of 13,000 h-1 and 343 K. This selectivity could be increased by lowering the hydrogen/butanedinitrile ratio.
- Serra, Marc,Salagre, Pilar,Cesteros, Yolanda,Medina, Francisco,Sueiras, Jesus E.
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p. 210 - 219
(2007/10/03)
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- Photooxidative decarboxylation of proline, a novel oxidative stress to natural amines
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Proline was decarboxylated quantitatively to Δ1-pyrroline on photoirradiation in the presence of rose bengal, while its methyl ester yielded an equimolar mixture of Δ1- and Δ5-pyrroline-2-carboxylic acid methyl esters. The decarboxylation of proline took place under either an aerobic (O2 bubbling) or an anaerobic (N2 bubbling) conditions, and under the latter condition, extent of the reaction depended on the amount of rose bengal employed. These results imply mechanistically that the reaction is the Type I photooxidation, indicating a new type of oxidative stress to natural secondary amines.
- Endo, Katsuya,Hirayama, Kaoru,Aota, Yuko,Seya, Kazuhiko,Asakura, Hirotatsu,Hisamichi, Kanehiko
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p. 865 - 870
(2007/10/03)
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- Catalytic oxidation of amines utilizing binuclear copper(II) complex of 7-azaindole
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Treatment of benzylamine with a catalytic amount of a binuclear copper(II) complex of 7-azaindole 1 under an oxygen atmosphere at room temperature produced benzylidene-benzylamine and benzonitrile in good yields. This reaction is also applicable to other amines and gives the corresponding imines. Interestingly 1-phenylpyrrolidine was oxidized to cyclic dimers, but, in the presence of triethylamine, it was oxidized to the corresponding γ-lactam.
- Minakata, Satoshi,Ohshima, Yasuhito,Takemiya, Akihiro,Ryu, Ilhyong,Komatsu, Mitsuo,Ohshiro, Yoshiki
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p. 311 - 312
(2007/10/03)
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- Quantitation of Important Roast-Smelling Odorants in Popcorn by Stable Isotope Dilution Assays and Model Studies on Flavor Formation during Popping
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Stable isotope dilution assays were developed for the quantitation of the roast-smelling popcorn odorants, 2-acetyl-tetrahydropyridine (ACTPY) and 2-propionyl-1-pyrroline (PPY).Both and, in addition, the two further roast-aroma compounds, 2-acetyl-1-pyrroline (ACPY) and acetylpyrazine, were quantified in different popcorn samples.In fresh hot-air popped corn, ACTPY showed the highest concentration (437 μg/kg), followed by ACPY (24 μg/kg) which were established as the key contributors to the roasty popcorn odor.During storage of a popcorn sample for seven days in a sealed polyethylene bag, the concentrations of ACTPY, ACPY, and PPY decreased to about one third.Model studies using aqueous maize extracts and distinct precursor compounds revealed the pair proline/fructose as the most effective precursor system in ACTPY formation, while the pair 1-pyrroline/2-oxopropanal was most effective in the generation of ACPY.A reaction scheme suggesting that ACPY is formed by an "acylation" of the intermediate 1-pyrroline by 2-oxopropanal in discussed.Keywords: 2-Acetyltetrahydropyridine; 2-acetyl-1-pyrroline; 2-propionyl-2-pyrroline; 2-benzoyl-1-pyrroline; stable isotope dilution assay; popcorn; flavor formation
- Schieberle, Peter
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p. 2442 - 2448
(2007/10/02)
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- Short syntheses of (±)-tetraponerines-5 and -6. The structures of tetraponerines-1 and -2, and a revision of the structures of (+)-tetraponerines-5 and 6.
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The structures and absolute configurations of (+)-tetraponerines-5 and -6 [(+)-T-5 and (+)-T-6], from the poison gland of the ant Tetraponera sp., were reassigned as 7 and 8, respectively, on the basis of extensive two-dimensional NMR and CD studies. These results led to structure proposals 9 for T-1 and 10 for T-2, the two minor alkaloids of the venom. The structures and relative configuration of T-5 and T-6 were subsequently confirmed by short stereoselective syntheses.
- Devijver,Macours,Braekman,Daloze,Pasteels
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p. 10913 - 10922
(2007/10/02)
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- Electronic Structure and Gas-Phase Thermolysis of 2-Tetrazenes with Acyclic or Cyclic Amino Groups Studied by Photoelectron Spectroscopy
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The electronic structures and the gas-phase thermolysis of the 2-tetrazenes 2-13 have been studied by He(I) photoelectron spectroscopy.The compounds are characterized by at least three ionization potentials with energies less than 10 eV which are assigned to the molecular orbitals ?3 (HOMO), n(+), ?2, and n(-).In the thermolyses either the formal disproportionation products (amine and imine) of the respective aminyl radical are found, or the latter is stabilized by loss of an alkyl radical affording also an imine.Further products which can be explained by radical reactions are detected in flash vacuum pyrolyses.The tricyclic cis-2-tetrazene 13 is cleaved by cycloreversion.The methoxymethylsubstituted compound 8 exhibit a more complex cleavage pattern. - Key Words: Electronic structure / PE spectroscopy / Thermolysis, gas-phase / Imines / Radicals
- Rademacher, Paul,Heymanns, Peter,Muenzenberg, Ralf,Woell, Heike,Kowski, Klaus,Poppek, Rainer
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p. 2073 - 2080
(2007/10/02)
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- Competing Radical, Carbanion, and Carbene Pathways in the Reactions of Hindered Primary Alkyl Halides with Lithium Dialkylamides
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A variety of methods were utilized to study the mechanism of reaction of 6-iodo-5,5-dimethyl-1-hexene and its bromo, chloro, and tosylate derivatives with LDA and several other lithium dialkylamides.In the reaction of 6-iodo-5,5-dimethyl-1-hexene with LDA in THF, radical, carbanion, and carbene pathways occured simultaneously.However, when the corresponding bromide was allowed to react with LDA, the radical pathway was minor and when the corresponding chloride or tosylate was allowed to react with LDA, no evidence for radical products was observed.This is the first time that competing radical, carbanion, and carbene pathways have been detected in the reaction of a primary alkyl halide with any nucleophile.
- Ashby, E. C.,Park, B.,Patil, G. S.,Gadru, K.,Gurumurthy, R.
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p. 424 - 437
(2007/10/02)
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- PEA-SEEDLING DIAMINE OXIDASE: APPLICATIONS IN SYNTHESIS AND EVIDENCE RELATING TO ITS MECHANISM OF ACTION
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Diamines (6)-(8) and (11) act as acceptable substrates for diamine oxidase (DAO) and the novel phenacyl derivatives (2) are obtained in satisfactory preparative yield; no enantioselectivity is observed with (11) as an enzyme substrate.Remarkably, the triamines (9) and (13) are not oxidized and, moreover, (9) acts as a notable inhibitor for the DAO catalysed oxidation of (4) and (5).Kinetic evidence relevant to the mechanism of DAO action is presented, and is discussed in terms of a model for DAO-catalysed oxidation.
- Cragg, John E.,Herbert, Richard B.,Kgaphola, Mashupye M.
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p. 6907 - 6910
(2007/10/02)
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- SYNTHESE D'IMINES LINEAIRES NON-STABILISEES PAR REACTIONS GAZ-SOLIDE SOUS VIDE(1).
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Unstabilized imines are synthetized in gram-scale by vacuum dehydrochlorination of N-chloroalkylamines and by vacuum dehydrocyanation of α-aminonitriles on solid base.All the new compounds are characterized at low temperature by 1H, 13C NMR and IR spectroscopy.
- Guillemin, Jean-Claude,Denis, Jean-Marc
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p. 4431 - 4446
(2007/10/02)
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- OXIDATIVE DECARBOXYLATION OF CYCLIC AMINO ACIDS AND DEHYDROGENATION OF CYCLIC SECONDARY AMINES WITH IODOSOBENZENE
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Cyclic amino acids L-proline, pipecolinic acid and L-2-pyrrolidinone-5-carboxylic acid undergo oxidative decarboxylation with iodosobenzene in various solvents (including water) to yield the lactam and imide in the latter case.The reaction proceeds via initial imine formation.
- Ochiai, Masahito,Inenaga, Minako,Nagao, Yoshimitsu,Moriarty, Robert M.,Vaid, Radhe K.,Duncan, Michael P.
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p. 6917 - 6920
(2007/10/02)
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- Gasphase Reactions, 61. - Cycloalkanimines 2H-Azirine, 1-Azetidine, 1-Pyrroline, 1-Piperideine, and 3,4,5,6-Tetrahydro-2H-azepine: Preparation and Photoelectron Spectra
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For preparation of the easily oligomerizing cycloalkanimines , the following gasphase reactions are optimized PE spectroscopically: for the three membered ring imine, 2H-azirine, the heterogeneous KOR dehydrochlorination of the 2-chloroethyl azide preceding the thermolysis of the resulting vinyl azide, and for the lager rings, 1-azetine (n=2), 1-pyrroline (n=3), 1-piperideine (n=4) as well as the seven-membered 3,4,5,6-tetrahydro-2H-azepine, the consecutive chlorination of the corresponding cycloalkylamine over solid N-chlorosuccinimide followed by KOR dehydrochlorination of the N-chloro derivative formed.The PE spectra of all cyclic alkanimines prepared are assigned based on geometry-optimized MNDO calculations, and their electronic structures are discussed by molecular state comparison with increasing ring size and with the isoelectronic series of the cycloalkenes.The thermal ring opening of 1-azetine to 2-azabutadiene is investigated by PE spectroscopic real-time gas analysis; its ionization pattern is assigned by comparison with other azabutadienes.
- Bock, Hans,Dammel, Ralph
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p. 1971 - 1986
(2007/10/02)
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- Biosynthesis of Phenanthroindolizidine Alkaloids: Incorporation of 2-Pyrrolidin-2-ylacetophenone and Benzoylacetic Acid and Derivatives
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2-Pyrrolidin-2-ylacetophenone (12) and its oxygenated derivatives, (13) and (14), bearing 14C and 3H labels are synthesized and are shown to be intact precursors for the phenanthroindolizidine alkaloid, tylophorinine (16), in Tylophora asthmatica; the three amines, singly labelled with tritium, are shown to be precursors for tylophorine (3) and tylophorinidine (17).Benzoylacetic acid (9) and p-hydroxybenzoylacetic acid (10), but not 4-hydroxy-3-methoxybenzoylacetic acid, are also precursors for tylophorinine (16).The results allow partial description of the biosynthetic pathways tophenanthroindolizidine alkaloids.A degradation is described which allowed the location of label in 2-pyrrolidin-2-ylacetophenone, derived from ornithine, to be established.
- Herbert, Richard B.,Jackson, Frederick B.,Nicolson, Ian T.
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p. 825 - 831
(2007/10/02)
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