2436-90-0Relevant articles and documents
Regiodivergent reduction of allylic esters with Samarium(II) iodide by tuning ester groups and proton sources
Yoshida, Akihiro,Hanamoto, Takeshi,Inanaga, Junji,Mikami, Koichi
, p. 1777 - 1780 (1998)
Samarium(II) iodide reduced allylic esters in the presence or the absence of palladium(0) catalyst to give α- and γ-protonated products in a regiodivergent fashion by tuning ester functionality and proton sources.
A chemoselective and regioselective catalytic way to a novel nine-membered lactone
Lenoble, Géraldine,Urrutigo?ty, Martine,Kalck, Philippe
, p. 3697 - 3700 (2001)
Cyclocarbonylation of dihydromyrcenol into the corresponding lactone can be selectively performed in the presence of PdCl2(PPh3)2)/SnCl2·2H 2O and 4 A? molecular sieves.
Total Synthesis and Biological Investigation of (?)-Artemisinin: The Antimalarial Activity of Artemisinin Is not Stereospecific
Krieger, Johannes,Smeilus, Toni,Kaiser, Marcel,Seo, Ean-Jeong,Efferth, Thomas,Giannis, Athanassios
, p. 8293 - 8296 (2018)
Here, we describe an efficient and diversity-oriented entry to both (?)-artemisinin (1) and its natural antipode (+)-artemisinin, starting from commercially and readily available S-(+)- and R-(?)-citronellene, respectively. Subsequently, we answered the still open question regarding the specificity of artemisinins action. By using a drug-sensitive Plasmodium falciparum NF54 strain, we showed that the antimalarial activity of artemisinin is not stereospecific. Our straightforward and biomimetic approach to this natural endoperoxide enables the synthesis of artemisinin derivatives that are not accessible through applying current methods and may help to address the problem of emerging resistance of Plasmodium falciparum towards artemisinin.
Method for preparing guaipyridine type sesquiterpenoid alkaloid
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Paragraph 0036-0039, (2021/09/21)
The invention relates to a method for preparing guaipyridine type sesquiterpenoid alkaloids. The method is characterized in that a plurality of guaipyridine type sesquiterpenoid alkaloids are obtained by changing segments of intermediates and changing subsequent functional groups, and asymmetric total synthesis of rupestine D and guaipyridine is realized. The method has the characteristic of flexible divergent synthesis, and provides a new way for subsequent screening of compounds with better biological activity. Rupestine D and guaipydine, which are obtained by the method, are subjected to optical rotation, nuclear magnetic data, high-resolution mass spectrum, single crystal and other contrasts with a naturally separated sample, so that the chemical structure and the spatial configuration of the rupestine D and guaipydine are determined.
Transition metal triflate catalyzed conversion of alcohols, ethers and esters to olefins
Keskiv?li,Parviainen,Lagerblom,Repo
, p. 15111 - 15118 (2018/05/04)
Herein, we report an efficient transition metal triflate catalyzed approach to convert biomass-based compounds, such as monoterpene alcohols, sugar alcohols, octyl acetate and tea tree oil, to their corresponding olefins in high yields. The reaction proceeds through C-O bond cleavage under solvent-free conditions, where the catalytic activity is determined by the oxophilicity and the Lewis acidity of the metal catalyst. In addition, we demonstrate how the oxygen containing functionality affects the formation of the olefins. Furthermore, the robustness of the used metal triflate catalysts, Fe(OTf)3 and Hf(OTf)4, is highlighted by their ability to convert an over 2400-fold excess of 2-octanol to octenes in high isolated yields.
Photocatalytic Transfer Hydrogenolysis of Allylic Alcohols on Pd/TiO2: A Shortcut to (S)-(+)-Lavandulol
Takada, Yuki,Caner, Joaquim,Kaliyamoorthy, Selvam,Naka, Hiroshi,Saito, Susumu
supporting information, p. 18025 - 18032 (2017/12/08)
We report herein a regio- and stereoselective photocatalytic hydrogenolysis of allylic alcohols to form unsaturated hydrocarbons employing a palladium(II)-loaded titanium oxide; the reaction proceeds at room temperature under light irradiation without stoichiometric generation of salt wastes. Olefin and saturated alcohol moieties tolerated the reaction conditions. Hydrogen atoms were selectively incorporated into less sterically congested carbons of the allylic functionalities. This protocol allowed a short-step synthesis of (S)-(+)-lavandulol from (R)-(?)-carvone by avoiding otherwise necessary protection/deprotection steps.
Process for the Catalytic Reversible Alkene-Nitrile Interconversion
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Page/Page column 28, (2017/09/02)
The present invention refers to processes for catalytic reversible alkene-nitrile interconversion through controllable HCN-free transfer hydrocyanation.
Elaboration of Sterically Hindered δ-Lactones through Ring-Closing Metathesis: Application to the Synthesis of the C1-C27 Fragment of Hemicalide
Lecourt, Camille,Boinapally, Srikanth,Dhambri, Sabrina,Boissonnat, Guillaume,Meyer, Christophe,Cossy, Janine,Sautel, Fran?ois,Massiot, Georges,Ardisson, Janick,Sorin, Geoffroy,Lannou, Marie-Isabelle
, p. 12275 - 12290 (2016/12/23)
The synthesis of the C1-C27 fragment of hemicalide, a marine metabolite displaying a unique potent antiproliferative activity, has been accomplished. The synthetic approach highlights a remarkably efficient ring-closing metathesis reaction catalyzed by Nolan ruthenium indenylidene complexes to elaborate the highly substituted δ-lactone framework.
Taking advantage of a terpyridine ligand for the deposition of Pd nanoparticles onto a magnetic material for selective hydrogenation reactions
Guerrero, Miguel,Costa, Natalia J. S.,Vono, Lucas L. R.,Rossi, Liane M.,Gusevskaya, Elena V.,Philippot, Karine
, p. 1441 - 1449 (2013/07/05)
A hybrid terpyridine ligand was designed to functionalize a magnetic support constituted of magnetite cores surrounded by a silica shell with the aim of improving the stabilization of supported-palladium nanoparticles for the later application of the obtained composite nanomaterial in hydrogenation catalysis. The preparation of the nanomaterial was performed by direct decomposition of the organometallic complex [Pd2(dba)3] on the terpyridine-modified magnetic support providing well-dispersed Pd NPs of 2.5 ± 0.6 nm mean size. This new nanomaterial is a highly active catalyst for the hydrogenation of cyclohexene under mild conditions reaching turnover frequencies up to ca. 58000 h-1 or 129000 h-1 when corrected for surface Pd atoms. Furthermore, in the hydrogenation of β-myrcene, this nanocatalyst is highly selective for the formation of monohydrogenated compounds. When compared to a similar nanocatalyst consisting of palladium nanoparticles supported on an amino-modified magnetic support or on Pd/C, the activity and selectivity of the nanocatalyst are largely increased. These results show how the design of an appropriate hybrid ligand used to functionalize the support can strongly influence the catalytic properties of supported metal nanoparticles. The Royal Society of Chemistry 2013.
Unique catalysis of gold nanoparticles in the chemoselective hydrogenolysis with H2: Cooperative effect between small gold nanoparticles and a basic support
Noujima, Akifumi,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 6723 - 6725 (2012/07/28)
Gold nanoparticles on hydrotalcite act as a heterogeneous catalyst for the chemoselective hydrogenolysis of various allylic carbonates to the corresponding terminal alkenes using H2 as a clean reductant. The combination of gold nanoparticles and basic supports elicited significantly unique and selective catalysis in the hydrogenolysis.