51652-47-2Relevant academic research and scientific papers
INSECT PHEROMONES AND THEIR ANALOGUES XXXI. SYNTHESIS OF DEC-5Z-EN-1-YL ACETATE AND HENEICOS-6Z-EN-11-ONE FROM A FUNCTIONALLY DIFFERENTIATED PRODUCT OF THE OZONOLYSIS OF CYCLOPENTENE
Odinokov, V. N.,Akhmetova, V. R.,Khasanov, Kh. D.,Abduvakhabov, A. A.,Tolstikov, O. A.
, p. 497 - 499 (1991)
Dec-5Z-en-1-yl acetate and heneicos-6Z-en-11-one - pheromones of insects of the genera Agrotis and Orgyia, respectively - have been synthesized from a product of the functionally differentiated ozonolysis of cyclopentene.
PHEROMONES, 71. IDENTIFICATION AND SYNTHESIS OF FEMALE SEX PHEROMONE OF ERI-SILKWORM, Samia cynthia ricini (LEPIDOPTERA: SATURNIIDAE)
Bestmann, Hans Juergen,Attygalle, Athula B.,Schwarz, Juergen,Garbe, Wolfgang,Vostrowsky, Otto,Tomida, Ichiro
, p. 2911 - 2914 (1989)
(4E,6E,11Z)-4,6,11-Hexadecatrienal and (4E,6E,11Z)-4,6,11-hexadecatrienyl acetate were identified as the major components of the sex pheromone of the eri-silkworm, Samia cynthia ricini, females.
An Amine-Assisted Ionic Monohydride Mechanism Enables Selective Alkyne cis-Semihydrogenation with Ethanol: From Elementary Steps to Catalysis
Huang, Zhidao,Wang, Yulei,Leng, Xuebing,Huang, Zheng
supporting information, p. 4824 - 4836 (2021/04/07)
The selective synthesis of Z-alkenes in alkyne semihydrogenation relies on the reactivity difference of the catalysts toward the starting materials and the products. Here we report Z-selective semihydrogenation of alkynes with ethanol via a coordination-induced ionic monohydride mechanism. The EtOH-coordination-driven Cl- dissociation in a pincer Ir(III) hydridochloride complex (NCP)IrHCl (1) forms a cationic monohydride, [(NCP)IrH(EtOH)]+Cl-, that reacts selectively with alkynes over the corresponding Z-alkenes, thereby overcoming competing thermodynamically dominant alkene Z-E isomerization and overreduction. The challenge for establishing a catalytic cycle, however, lies in the alcoholysis step; the reaction of the alkyne insertion product (NCP)IrCl(vinyl) with EtOH does occur, but very slowly. Surprisingly, the alcoholysis does not proceed via direct protonolysis of the Ir-C(vinyl) bond. Instead, mechanistic data are consistent with an anion-involved alcoholysis pathway involving ionization of (NCP)IrCl(vinyl) via EtOH-for-Cl substitution and reversible protonation of Cl- ion with an Ir(III)-bound EtOH, followed by β-H elimination of the ethoxy ligand and C(vinyl)-H reductive elimination. The use of an amine is key to the monohydride mechanism by promoting the alcoholysis. The 1-amine-EtOH catalytic system exhibits an unprecedented level of substrate scope, generality, and compatibility, as demonstrated by Z-selective reduction of all alkyne classes, including challenging enynes and complex polyfunctionalized molecules. Comparison with a cationic monohydride complex bearing a noncoordinating BArF- ion elucidates the beneficial role of the Cl- ion in controlling the stereoselectivity, and comparison between 1-amine-EtOH and 1-NaOtBu-EtOH underscores the fact that this base variable, albeit in catalytic amounts, leads to different mechanisms and consequently different stereoselectivity.
Synthesis and Immobilization of Metal Nanoparticles Using Photoactive Polymer-Decorated Zeolite L Crystals and Their Application in Catalysis
Wissing, Maren,Niehues, Maximilian,Ravoo, Bart Jan,Studer, Armido
supporting information, p. 2245 - 2253 (2020/05/05)
A facile route to generate Au and Pd nanoparticles (NPs) on zeolite L crystals decorated with photoactive polymer brushes is described. The polymers used in this approach serve a dual role: Upon irradiation with UV light, they release highly reducing ketyl radicals in a Norrish-Type-I reaction. These radicals serve as one electron donors to reduce metal salts to the corresponding metal NPs. At the same time the polymer shell stabilizes the in situ generated metal NPs. It is shown that the zeolite-polymer-NP composites can be used as recyclable catalysts for the oxidation of benzylic alcohols to aldehydes and the stereoselective semihydrogenation of alkynes to Z-alkenes. The polymer shell in these hybrid catalysts protects the NPs from aggregation and also alters their catalytic properties. (Figure presented.).
Stereoselective Alkyne Hydrogenation by using a Simple Iron Catalyst
Gregori, Bernhard J.,Schwarzhuber, Felix,P?llath, Simon,Zweck, Josef,Fritsch, Lorena,Schoch, Roland,Bauer, Matthias,Jacobi von Wangelin, Axel
, p. 3864 - 3870 (2019/07/31)
The stereoselective hydrogenation of alkynes constitutes one of the key approaches for the construction of stereodefined alkenes. The majority of conventional methods utilize noble and toxic metal catalysts. This study concerns a simple catalyst comprised of the commercial chemicals iron(II) acetylacetonate and diisobutylaluminum hydride, which enables the Z-selective semihydrogenation of alkynes under near ambient conditions (1–3 bar H2, 30 °C, 5 mol % [Fe]). Neither an elaborate catalyst preparation nor addition of ligands is required. Mechanistic studies (kinetic poisoning, X-ray absorption spectroscopy, TEM) strongly indicate the operation of small iron clusters and particle catalysts.
Pyrrolidines and Piperidines by Ligand-Enabled Aza-Heck Cyclizations and Cascades of N-(Pentafluorobenzoyloxy)carbamates
Hazelden, Ian R.,Carmona, Rafaela C.,Langer, Thomas,Pringle, Paul G.,Bower, John F.
supporting information, p. 5124 - 5128 (2018/03/26)
Ligand-enabled aza-Heck cyclizations and cascades of N-(pentafluorobenzoyloxy)carbamates are described. These studies encompass the first examples of efficient non-biased 6-exo aza-Heck cyclizations. The methodology provides direct and flexible access to carbamate protected pyrrolidines and piperidines.
Facile Light-Mediated Preparation of Small Polymer-Coated Palladium-Nanoparticles and Their Application as Catalysts for Alkyne Semi-Hydrogenation
M?sing, Florian,Wang, Xi,Nüsse, Harald,Klingauf, Jürgen,Studer, Armido
supporting information, p. 6014 - 6018 (2017/05/05)
A facile light-mediated preparation of small palladium nanoparticles (PdNPs) with a diameter of 1.3 nm and low dispersity by using low-priced and readily prepared photoactive polymers is presented. These polymers act as reagents for the photochemical reduction of Pd ions and they are also stabilizers for the PdNPs generated in situ. The PdNP–polymer hybrid materials prepared by this reliable approach are efficient hydrogenation catalysts that show high activity and Z-selectivity in the semi-hydrogenation of alkynes. These PdNP–catalyst hybrid materials can be readily recycled and reused up to five times.
Light Mediated Preparation of Palladium Nanoparticles as Catalysts for Alkyne cis-Semihydrogenation
M?sing, Florian,Nüsse, Harald,Klingauf, Jürgen,Studer, Armido
supporting information, p. 2658 - 2661 (2017/05/24)
A bisacylphosphine oxide photoinitiator was used for the light mediated preparation of palladium nanoparticles (PdNPs) with a small diameter of 2.8 nm. All starting materials are commercially available, and PdNP synthesis is experimentally very easy to conduct. The PdNP-hybrid material was applied as catalyst for the semihydrogenation of various internal alkynes to provide the corresponding alkenes in excellent yields (up to 99%) and Z-selectivities (Z/E ratios up to 99/1).
Synthesis of heneicos-6(Z)-en-11-one, dec-5(Z)-en-l-yl acetate, dec-5(Z)-En-1-y1-3-methylbutanoate (insect sex pheromones)
Jindal, Rani,Devi, Aarti,Kad, Goverdhan L.,Singh, Jasvinder
experimental part, p. 495 - 499 (2010/10/20)
Synthesis of heneicos-6(Z)-en-11-one 1, dec-5(Z)-en-l-yl acetate 2, dec-5(Z)-en-l-yl-3-methylbutanoate 3 has been accomplished by utilizing sodium acetoxyborohydride generated in situ from sodium borohydride and acetic acid as the key step for selective hydroboration-iodination/oxidation.
A selective Ru-catalyzed semireduction of alkynes to Z olefins under transfer-hydrogenation conditions
Belger, Christian,Neisius, N. Matthias,Plietker, Bernd
supporting information; experimental part, p. 12214 - 12220 (2011/03/17)
By using a readily available, air- and moisture-stable dihydrido-Ru complex, a variety of Z olefins are accessible under transfer-hydrogenation conditions with formic acid as the hydrogen source in excellent yields and Z/E selectivities. A discerning transformation: Z-Configured C=C bonds are stereoselectively formed from alkynes in the presence of a Ru catalyst with formic acid as the sole H2 source at room temperature (see scheme). A variety of functional groups are compatible with this novel procedure. Operational simplicity and the lack of overreduction products are characteristics for this unprecedented process.
