136521-14-7Relevant articles and documents
Enantiospecific Total Synthesis of (-)-Japonicol C
Dethe, Dattatraya H.,Nirpal, Appasaheb K.
supporting information, p. 2648 - 2653 (2021/04/12)
An efficient and convergent first total syntheses of (±)-japonicol B and (-)-japonicol C have been completed. The notable points of the synthetic route are Lewis-acid-catalyzed Friedel-Crafts reaction for one pot C-C and C-O bond formations resulting in c
Iron-catalyzed chemoselective hydride transfer reactions
Coufourier, Sébastien,Ndiaye, Daouda,Gaillard, Quentin Gaignard,Bettoni, Léo,Joly, Nicolas,Mbaye, Mbaye Diagne,Poater, Albert,Gaillard, Sylvain,Renaud, Jean-Luc
supporting information, (2021/06/07)
A Diaminocyclopentadienone iron tricarbonyl complex has been applied in chemoselective hydrogen transfer reductions. This bifunctional iron complex demonstrated a broad applicability in mild conditions in various reactions, such as reduction of aldehydes over ketones, reductive alkylation of various functionalized amines with functionalized aldehydes and reduction of α,β-unsaturated ketones into the corresponding saturated ketones. A broad range of functionalized substrates has been isolated in excellent yields with this practical procedure.
Room-Temperature Chemoselective Reductive Alkylation of Amines Catalyzed by a Well-Defined Iron(II) Complex Using Hydrogen
Lator, Alexis,Gaillard, Quentin Gaignard,Mérel, Delphine S.,Lohier, Jean-Fran?ois,Gaillard, Sylvain,Poater, Albert,Renaud, Jean-Luc
, p. 6813 - 6829 (2019/06/07)
A transition-metal frustrated Lewis pair approach has been envisaged to enhance the catalytic activity of tricarbonyl phosphine-free iron complexes in reduction of amines. A new cyclopentadienyl iron(II) tricarbonyl complex has been isolated, fully characterized, and applied in hydrogenation. This phosphine-free iron complex is the first Earth-abundant metal complex that is able to catalyze chemoselective reductive alkylation of various functionalized amines with functionalized aldehydes. Such selectivity and functionality tolerance (alkenes, esters, ketones, acetals, unprotected hydroxyl groups, and phosphines) have been demonstrated also for the first time at room temperature with an Earth-abundant metal complex. This alkylation reaction was also performed without any preliminary condensation and generated only water as a byproduct. The resulting amines provided rapid access to potential building blocks, metal ligands, or drugs. Density functional theory calculations highlighted first that the formation of the 16 electron species, via the activation of the tricarbonyl complex Fe3, was facilitated and, second, that the hydrogen cleavage did not follow the same pathway as bond breaking, usually described with the known cyclopentadienone iron tricarbonyl complexes (Fe1 and Fe4). These calculations highlighted that the new complex Fe3 does not behave as a bifunctional catalyst, in contrast to its former congeners.
Asymmetric Synthesis and Structure Revision of Guignardone H and I: Development of a Chiral 1,3-Diketone Possessing C2 Symmetry
Kobayashi, Toyoharu,Takizawa, Iori,Shinobe, Ayumu,Kawamoto, Yuichiro,Abe, Hideki,Ito, Hisanaka
supporting information, p. 3008 - 3012 (2019/05/10)
A novel chiral 1,3-diketone possessing C2 symmetry was synthesized and utilized in the asymmetric synthesis of guignardone H and I by employing sequential condensation-6?-electrocyclization reactions with the novel 1,3-diketone followed by ster
Ozonolytic Transformations of (S)-(–)-Limonene and Abietic Acid in the Presence of Pyridine
Myasoedova, Yu. V.,Garifullina,Nurieva,Kravchenko,Ishmuratov, G. Yu.
, p. 474 - 477 (2019/07/02)
Controlled ozonolysis of (S)-(–)-limonene in the presence of Py gave 4-methyl-3-(3-oxobutyl)pent-4-enal or 4-methyl-3-(3-oxobutyl)pent-4-enoic acid depending on the solvent (CH2Cl2 or MeOH). Exhaustive ozonolysis produced 3-acetyl-6-oxoheptanoic acid. Ozonolysis of abietic acid in CH2Cl2 in the presence of Py formed stable epoxytrioxolaneabietic acid; in MeOH–Py, the epoxyketoaldehyde corresponding to cleavage of the C13–C14 bond.
Synthesis of 12-epi-Protopanaxadiol and Formal Synthesis of Ginsenoside Chikusetsusaponin-LT8
Evanno, Laurent,Belotti, Damien,Toromanoff, Edmond,Cossy, Janine
supporting information, p. 5970 - 5973 (2019/08/26)
In the context of the total synthesis of protopanaxadiol, two strategies were explored. One strategy from an optically active trienic epoxide, possessing a 5-membered ring, prepared from (S)-epoxy-limonene and (S)-epoxyfarnesol, which was submitted to Ti-(III)-mediated radical cascade to afford an original tetracyclic structure resulting from a 6-endo-trig 6-endo-trig 8-endo-trig process. A second strategy, starting from a Wieland-Miescher-type ketone, using a “ring-by-ring” synthesis allowed the synthesis of 12-epi-protopanaxadiol. In this latter strategy, an efficient sequence of reactions to install the two vicinal C8–C14 quaternary centers involves: i) a Barbier type reaction; ii) an oxidative allylic transposition and iii) a nickel-catalyzed addition of trimethylaluminium. By using this second strategy, 20-hydroxydammar-24-ene-3,12-dione was synthesized which represents a formal synthesis of chikusetsusaponin-LT8, isolated from Panax japonicus.
Total Syntheses of (-)-Englerins A/B, (+)-Orientalols E/F, and (-)-Oxyphyllol
Liu, Pengcai,Cui, Yutao,Chen, Kang,Zhou, Xinyue,Pan, Wenyan,Ren, Jun,Wang, Zhongwen
supporting information, p. 2517 - 2521 (2018/05/17)
(-)-Englerin A was synthesized in 20 steps from the commercially available material (R)-(+)-limonene. In addition, (-)-englerin B, (+)-orientalol E/F and (-)-oxyphyllol were obtained from the intermediate in the route. The key steps include a hydroxyl-directing stereoselective and regioselective intramolecular cyclopropanation and a multi-gram-scale stereoselective formal intramolecular [3 + 2] cross cycloaddition ([3 + 2]-IMCC) of a cyclopropane 1,1-diester with a carbonyl. A precursor of 7,10-diastereoisomer of englerins was also obtained.
Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones
Zimmermann, Nicole,Hilgraf, Robert,Lehmann, Lutz,Ibarra, Daniel,Francke, Wittko
supporting information; experimental part, p. 1246 - 1255 (2012/10/08)
Starting from the enantiomers of limonene, all eight stereoisomers of trans-fused dihydronepetalactones were synthesized. Key compounds were pure stereoisomers of 1-acetoxymethyl-2-methyl-5-(2-hydroxy-1-methylethyl)-1- cyclopentene. The stereogenic center of limonene was retained at position 4a of the target compounds and used to stereoselectively control the introduction of the other chiral centers during the synthesis. Basically, this approach could also be used for the synthesis of enantiomerically pure trans-fused iridomyrmecins. Using synthetic reference samples, the combination of enantioselective gas chromatography and mass spectrometry revealed that volatiles released by the endohyperparasitoid wasp Alloxysta victrix contain the enantiomerically pure trans-fused (4R,4aR,7R,7aS)-dihydronepetalactone as a minor component, showing an unusual (R)-configured stereogenic center at position 7.
Diastereodivergent synthesis of trisubstituted alkenes through protodeboronation of allylic boronic esters: Application to the synthesis of the californian red scale beetle pheromone
Hesse, Matthew J.,Butts, Craig P.,Willis, Christine L.,Aggarwal, Varinder K.
supporting information, p. 12444 - 12448 (2013/02/23)
E-allylic boronic esters undergo a highly diastereoselective protodeboronation with TBAF·3 H2O to give Z-trisubstituted alkenes. The selectivity can be switched to give predominantly the E-alkene instead by using KHF2/TsOH (see scheme). The utility of the methodology has been illustrated in a short synthesis of a component of the sex pheromone of the Californian red scale beetle. Copyright
Ozonolytic transformations of (S)-(-)-limonene
Yu Ishmuratov,Yu Legostaeva,Botsman,Nasibullina,Muslukhov,Kazakov,Tolstikov
, p. 18 - 24 (2012/05/20)
Partial ozonolysis of (S)-(-)-limonene in cyclohexane-methanol yields 1-methyl-4-(prop1-en-2-yl)-7,8,9-trioxabicyclo[4.2.1]nonane as a mixture of diastereoisomers at a ratio of 2 : 3. Nitrogen-containing organic compounds (semicarbazide and hydroxylamine
