19686-79-4Relevant academic research and scientific papers
A novel synthesis of 4-cycloheptenones
Marvell, Elliot N.,Titterington, Donald
, p. 2123 - 2124 (1980)
4-Cycloheptenones, mono and bicyclic, can be prepared by a base catalyzed thermal reaction of 1-hepten-6-yn-3-ols.
Enantioselective Synthesis of Tropanes: Br?nsted Acid Catalyzed Pseudotransannular Desymmetrization
Carrillo, Luisa,Merino, Pedro,Reyes, Efraim,Rodriguez, Sandra,Tejero, Tomás,Uria, Uxue,Vicario, Jose L.
supporting information, p. 6780 - 6784 (2020/03/19)
The enantioselective synthesis of tropanols has been accomplished through chiral phosphoric acid catalyzed pseudotransannular ring opening of 1-aminocyclohept-4-ene-derived epoxides. The reaction proceeds together with the desymmetrization of the starting
METHOD OF CYCLIC COMPOUNDS PRODUCTION IN OLEFINE METATHESIS REACTION AND USE OF RUTHENIUM CATALYSTS IN PRODUCTION OF CYCLIC OLEFINS IN OLEFINE METATHESIS REACTION
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Page/Page column 52; 53; 55; 56, (2018/11/22)
The invention relates to a method for the preparation of cyclic compounds in the metathesis of olefins from acyclic dienes comprising terminal and/or non-terminal C=C double bonds; the invention also relates to the use of homogeneous ruthenium complexes and homogeneous ruthenium complexes deposited on a solid support as catalysts and/or pre-catalysts for the preparation of cyclic olefins in olefin metathesis reactions. Formula (I)
At Long Last: Olefin Metathesis Macrocyclization at High Concentration
Sytniczuk, Adrian,Dabrowski, Micha?,Banach, ?ukasz,Urban, Mateusz,Czarnocka-?niada?a, Sylwia,Milewski, Mariusz,Kajetanowicz, Anna,Grela, Karol
supporting information, p. 8895 - 8901 (2018/07/05)
Macrocyclic lactones, ketones, and ethers can be obtained in the High-Concentration Ring-Closing Metathesis (HC-RCM) reaction in high yield and selectivity at concentrations 40 to 380 times higher than those typically used by organic chemists for similar macrocyclizations. The new method consists of using tailored ruthenium catalysts together with applying vacuum to distill off the macrocyclic product as it is formed by the metathetical backbiting of oligomers. Unlike classical RCM, no large quantities of organic solvents are used, but rather inexpensive nonvolatile diluents, such as natural or synthetic paraffin oils. Moreover, use of a protecting atmosphere or a glovebox is not needed, as the new catalysts are perfectly moisture and air stable. In addition, some other cyclic compounds previously reported as unobtainable by RCM in neat conditions, or in high dilutions even, can be formed with the help of the HC-RCM method.
Precision Polyketones by Ring-Opening Metathesis Polymerization: Effects of Regular and Irregular Ketone Spacing
Arrington, Kyle J.,Murray, Clifton B.,Smith, Emily C.,Marand, Hervé,Matson, John B.
, p. 3655 - 3662 (2016/06/09)
The synthesis and characterization of regioregular aliphatic polyketones is reported. Poly(1-oxoheptamethylene), a semicrystalline polyketone, was prepared via ruthenium-catalyzed ring-opening metathesis polymerization (ROMP) of a ketal-protected 7-membered cyclic ketone followed by subsequent hydrogenation and deprotection. Temperature and catalyst studies of the ROMP reaction guided the preparation of polyketones with high monomer conversions, molecular weights as high as 30 kDa, and dispersities as low as 1.4. Because of the symmetric nature of the monomer, the polymer has ketones spaced every six methylene units apart. The thermal properties of this polyketone were investigated by differential scanning calorimetry, revealing a peak melting range of 160-165 °C. A related polymer, poly(1-oxooctamethylene), was also prepared in a similar fashion, and a peak melting range of only 130-133 °C was observed. This difference in melting range is attributed to the lack of the regioregularity in poly(1-oxooctamethylene), which was derived from an asymmetric 8-membered ring monomer and has ketones spaced every 6, 7, or 8 methylene units apart.
TRANS-CYCLOHEPTENES AND HETERO-TRANS-CYCLOHEPTENES FOR BIOORTHOGONAL COUPLING
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Page/Page column 11, (2017/04/29)
A substituted trans-cycloheptene according to formula (I); wherein : a) Z and L are each selected from the group consisting of SiR1R2, CH2, CHOH, and CHR2; R1 is phenyl or CH3; R2 is phenyl, CH3, (CH2)nCN, or (CH2)nOH, wherein n is an integer from 1 to 5; Ra and Rb are each individually selected from the group consisting of H, OH, and CH3; and Z and L are not both SiR1R2; or b) Z is BocN, L is CH2, Ra is H, and Rb is H; or c) Z is C=0, L is CH2, Ra is H, and Rb is H.
The scent of bacteria: Headspace analysis for the discovery of natural products
Citron, Christian A.,Rabe, Patrick,Dickschat, Jeroen S.
supporting information, p. 1765 - 1776 (2013/01/15)
Volatile compounds released by 50 bacterial strains, 45 of them actinobacteria in addition to three chloroflexi and two myxobacteria, have been collected by use of a closed-loop stripping apparatus, and the obtained headspace extracts have been analyzed by GC-MS. Excluding terpenes that have recently been published elsewhere, 254 compounds from all kinds of compound classes have been identified. For unambiguous compound identification several reference compounds have been synthesized. Among the detected volatiles 12 new natural products have been found, in addition to mellein, which was released by Saccharopolyspora erythraea. The iterative PKS for this compound has recently been identified by in vitro experiments, but mellein production in S. erythraea has never been reported before. These examples demonstrate that headspace analysis is an important tool for the discovery of natural products that may be overlooked using conventional techniques. The method is also useful for feeding experiments with isotopically labeled precursors and was applied to investigate the biosynthesis of the unusual nitrogen compound 1-nitro-2-methylpropane, which arises from valine. Furthermore, several streptomycetes emitted compounds that were previously recognized as insect pheromones, thus questioning if bacterial symbionts are involved in insect communication.
Rate coefficients and products for gas-phase reactions of chlorine atoms with cyclic unsaturated hydrocarbons at 298 K
Sharma,Pushpa,Dhanya,Naik,Bajai
body text, p. 98 - 105 (2011/06/21)
Rate coefficients for the reaction of Cl atoms with cycloalkenes have been determined using the relative rate method, at 298 K and atmospheric pressure of N2. Reference molecule was n -hexane, and the concentrations of the organics were followed by gas chromatographic analysis. Cl atoms were prepared by photolysis of trichloroacetyl chloride at 254 nm. The relative rates of reactions of Cl atoms with cycloalkenes, with, respect to M-hexane, are measured as 1.12 ±0.38, 1.31 ±0.14, and 1.69±0.18forcyclopentene, cyclohexene, and cycloheptene, respectively. Considering the absolute value of the rate coefficient of the reaction of Cl atom with n-hexane as 3.03 ± 0.06 × 10-10 cm3 molecule-1 s -1, the rate coefficient values for cyclopentene, cyclohexene, and cycloheptene are calculated, to be (3.39 ± 1.08) × 10 -10, (3.97 ±0.43) × 10-10, and (5.12 ± 0.55) × 10-10 cm3 molecule-1 S -1', respectively. The experiments for each, molecule were repeated six to eight times, and the slopes and the rate coefficients given above are the average values of these measurements, and the quoted error includes 2σ as well as all other uncertainties in the measurement and calculations. The rate coefficient increases linearly with the number of carbon atoms, with an increment per additional CH2 group being (8.7 ± 1.6) × 11-12 cm3 molecule-1 s-1. Chloroketones and chloroalcohols, along with unsaturated, ketones and alcohols, were found to be the major products of Cl-atom-initiated oxidation of cycloalkenes in the presence of air. The atmospheric implications of these results are discussed, along with a comparison with the reported structure activity relationships.
Generation and trapping of cyclopentenylidene gold species: Four pathways to polycyclic compounds
Lemiere, Gilles,Gandon, Vincent,Cariou, Kevin,Hours, Alexandra,Fukuyama, Takahide,et al.
supporting information; experimental part, p. 2993 - 3006 (2009/09/04)
Cyclopentenylidene gold complexes can easily be formed from vinyl allenes through a Nazarov-like mechanism. Such carbenes may transform in four different ways into polycyclic frameworks: electrophilic cyclopropanation, C-H insertion, C-C migration, or proton shift. We have studied the selectivity of these different pathways and used our findings for the expedient preparation of valuable complex molecules. An application to the total synthesis of a natural product, Δ9(12)-capnellene,is presented. DFT computations were carried out to shed light on the me chanisms.
