74962-98-4Relevant academic research and scientific papers
Stereoretentive Olefin Metathesis Made Easy: In Situ Generation of Highly Selective Ruthenium Catalysts from Commercial Starting Materials
Müller, Daniel S.,Curbet, Idriss,Raoul, Yann,Le N?tre, Jér?me,Baslé, Olivier,Mauduit, Marc
supporting information, p. 6822 - 6826 (2018/10/31)
The in situ preparation of highly stereoretentive ruthenium-based metathesis catalysts is reported. This approach completely avoids the isolation of intermediates and air-sensitive catalysts, thus allowing for the rapid access and evaluation of numerous dithiolate Ru catalysts. A procedure was established to perform cross-metathesis reactions without the use of a glovebox, and on a small scale even Schlenk techniques are not required. Consequently, the chemistry displayed in this report is available to every practicing organic chemist and presents a powerful approach for the identification of new stereoretentive catalysts.
Toward a modular, bidirectional synthesis of (-)-mucocin
Raghavan, Sadagopan,Subramanian, S. Ganapathy
experimental part, p. 7529 - 7539 (2011/10/12)
A convergent stereoselective synthesis of the C13-C34 fragment of (-)-mucocin is described. The salient features include (a) the bidirectional synthesis of the C-2 symmetric C13-C21 subunit, (b) regio- and stereoselective preparation of a 1,3-diol derivative from a diene activated by NBS via intramolecular nucleophilic sulfinyl group participation, (c) utilizing the self-metathesis reaction to prepare a functionalized C10 alkene, and (d) regio- and stereoselective intermolecular epoxide opening to construct the ether bond between C20 and C24. An organocatalytic α-hydoxylation has been employed to create the C4 stereogenic center of C1-C12 subunit. Attempted union of the two subunits utilizing the B-alkyl Suzuki coupling did not succeed.
Structure-Activity relationship of aliphatic compounds for nematicidal activity against pine wood nematode (Bursaphelenchus xylophilus)
Seo, Seon-M.I.,Junheon, Kim,Eunae, Kim,Park, Hye-M.I.,Kim, Young-Joon,Park, I.L.-Kwon
experimental part, p. 1823 - 1827 (2010/09/09)
Nematicidal activity of aliphatic compounds was tested to determine a structure-activity relationship. There was a significant difference in nematicidal activity among functional groups. In a test with alkanols and 2E-alkenols, compounds with C8-C11 chain length showed 100% nematicidal activity against pine wood nematode, Bursaphelenchus xylophilus, at 0.5 mg/mL concentration. C6-C10 2E-alkenals exhibited >95% nematicidal activity, but the other compounds with C 11-C14 chain length showed weak activity. Nematicidal activity of alkyl acetates with C7-C11 chain length was strong. Compounds belonging to hydrocarbons, alkanals, and alkanoic acetates showed weak activity at 0.5 mg/mL concentration. Nematicidal activity of active compounds was determined at lower concentrations. At 0.25 mg/mL concentration, whole compounds except C8 alkanol, C8 2E-alkenol, and C7 alkanoic acid showed >80% nematicidal activity. C 9-C11 alkanols, C10-C11 2E-alkenols, C8-C9 2E-alkenals, and C9-C10 alkanoic acids showed >80% nematicidal activity at 0.125 mg/mL concentration. Only C11 alkanol exhibited strong nematicidal activity at 0.0625 mg/mL concentration, the lowest concentration that was tested. 2010 American Chemical Society.
Cobalt-catalyzed trimethylsilylmethylmagnesium-promoted radical alkenylation of alkyl halides: A complement to the Heck reaction
Affo, Walter,Ohmiya, Hirohisa,Fujioka, Takuma,Ikeda, Yousuke,Nakamura, Tomoaki,Yorimitsu, Hideki,Oshima, Koichiro,Imamura, Yuki,Mizuta, Tsutomu,Miyoshi, Katsuhiko
, p. 8068 - 8077 (2007/10/03)
A cobalt complex, [CoCl2(dpph)] (DPPH = [1,6- bis(diphenylphosphino)hexane]), catalyzes an intermolecular styrylation reaction of alkyl halides in the presence of Me3SiCH2MgCl in ether to yield β-alkylstyrenes. A variety of alkyl halides including alkyl chlorides can participate in the styrylation. A radical mechanism is strongly suggested for the styrylation reaction. The sequential isomerization/styrylation reactions of cyclopropylmethyl bromide and 6-bromo-1-hexene provide evidence of the radical mechanism. Crystallographic and spectroscopic investigations on cobalt complexes reveal that the reaction would begin with single electron transfer from an electron-rich (diphosphine)bis(trimethylsilylmethyl)cobalt(II) complex followed by reductive elimination to yield 1,2-bis(trimethylsilyl)ethane and a (diphosphine)cobalt(I) complex. The combination of [CoCl 2(dppb)] (DPPB = [1,4-bis(diphenylphosphino)butane]) catalyst and Me3SiCH2-MgCl induces intramolecular Heck-type cyclization reactions of 6-halo-1-hexenes via a radical process. On the other hand, the intramolecular cyclization of the prenyl ether of 2-iodophenol would proceed in a fashion similar to the conventional palladium-catalyzed transformation. The nonradical oxidative addition of carbon(sp2)-halogen bonds to cobalt is separately verified by a cobalt-catalyzed cross-coupling reaction of alkenyl halides with Me3SiCH2MgCl with retention of configuration of the starting vinyl halides. The cobalt-catalyzed intermolecular radical styrylation reaction of alkyl halides is applied to stereoselective variants. Styrylations of 1-alkoxy-2-bromocyclopentane derivatives provide trans-1-alkoxy-2-styrylcyclopentane skeletons, one of which is optically pure.
Synthesis of disparlure analogues, using resolution on microcrystalline cellulose triacetate-I
Inkster, James A. H.,Ling, Ivy,Honson, Nicolette S.,Jacquet, Loic,Gries, Regine,Plettner, Erika
, p. 3773 - 3784 (2007/10/03)
The gypsy moth, Lymantria dispar, uses a chiral epoxide, (+)-(7R,8S)-2-methyl-7,8-epoxyoctadecane, (+)-disparlure, as its main sex attractant. The moths can detect both enantiomers of disparlure and respond differently to each one. In an effort to understand the structure-activity relationships of the gypsy moth olfactory system, we prepared the analogues of (+)- and (-)-disparlure. The key intermediate in route to the analogues was 2-epoxytridecan-1-ol. Herein we report the resolution of 2-epoxytridecan-1-yl esters on microcrystalline cellulose triacetate and the synthesis of 5-oxa and (5Z)-ene analogues of (+)- and (-)-disparlure. An effort to make 5-aza analogues resulted in the formation of anti-5-(1-hydroxy-1-undecyl)-3-(3-methylbutyl) oxazolidin-2-one. The analogues were tested for their electroantennogram responses and for their ability to bind to pheromone-binding protein 1 (PBP1). We found that the 5-oxa analogues gave strong responses and that the antenna and the PBP1 no longer distinguish the enantiomers of the 5-oxa analogues. The analogues all bound the PBP1 with similar affinity to (-)-disparlure.
Scope and limitations of lithium-ethylenediamine-THF-mediated cleavage at the α-position of aromatics: Deprotection of aryl methyl ethers and benzyl ethers under mild conditions
Shindo, Takeyuki,Fukuyama, Yasuaki,Sugai, Takeshi
, p. 692 - 700 (2007/10/03)
The scope and limitation of lithium-ethylenediamine-THF-mediated reductive bond cleavage at the α-position of aromatics were examined. Very mild conditions such as lithium metal (5 equiv) and ethylenediamine (7 equiv) in oxygen-free THF were quite effective for the demethylation of aromatic ethers even at as low as -10°C. Allyl benzyl ethers were also deprotected under these conditions with very little change of the allylic alcohol moiety. Through this study, 2,6-dimethylbenzyl (m-xylylmethyl, MXM) group was developed as an alternative of benzyl group, which is readily cleavable under the above mentioned reductive conditions.
Rubrenolide, total synthesis and revision of its reported stereochemical structure
Thijs,Zwanenburg
, p. 5237 - 5252 (2007/10/03)
In this paper the synthesis of the natural product rubrenolide is presented. Due to an error in the original proposed stereochemical structure of rubrenolide, the synthesis was not straightforward. Application of the photo-induced rearrangement of an appropriate epoxy diazomethyl ketone gave access to the precursor lactone with an ee of 91%. Coupling of this lactone with (4S)-2,2-dimethyl-[1,3]-dioxolane-4-carbaldehyde gave, after some additional steps, the final product that was identical with an authentic sample of the natural product.
IMMUNOMODULATORY COMPOUNDS AND METHODS OF USE THEREOF
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Page 37, (2008/06/13)
The present invention is directed to methods of treating diseases and disorders related to immune responses by administering one or more immunomodulatory compounds. In particular, the invention is directed to methods of stimulating and reducing immune responses, treating autoimmune conditions, treating allergic reactions and asthma, and preventing ischemic damage and asthma by administering one or more immunomodulatory compounds.
Differential cleavage of arylmethyl ethers: Reactivity of 2,6-dimethoxybenzyl ethers
Falck,Barma,Baati, Rachid,Mioskowski, Charles
, p. 1281 - 1283 (2007/10/03)
CrCl2/LiI selectively cleave benzyl ethers and methoxy-substituted benzyl ethers (see scheme) in the order: C6H5CH2OR 6H4CH2OR 2C6H3CH2OR 2C6H3CH2OR. In contrast, C6H5CH2OR is more readily cleaved than 2,6-(MeO)2C6H3CH2OR during catalytic hydrogenolysis while 3,4-(MeO)2C6H3CH2OR is cleaved faster than 2,6-(MeO)2C6H3CH2OR with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ).
A simple synthetic method for chiral 1,2-epoxides and the total synthesis of a chiral pheromone epoxide
Zhang, Zhi-Bo,Wang, Zhi-Min,Wang, Yu-Xiu,Liu, Huan-Quan,Lei, Gui-Xin,Shi, Min
, p. 53 - 58 (2007/10/03)
Chiral 1,2-epoxyalkan-3-ol tosyl esters 4a-h were successfully synthesized from alkynols or allyl chlorides in three steps using Sharpless AD reaction as a key step in good yields. The chiral insect pheromone epoxide (6Z,9S,10R)-9,10-epoxyhenicos-6-ene 9 was thus smoothly synthesized from the corresponding key intermediate 4g.
