- Modular synthesis of a new family of tripodal ligands, all-cis-1,2,3- tris(diphenyl-phosphinomethyl)cyclopropane and relatives
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Equation Presented Bisbenzyl-protected all-cis-1,2,3-tris(hydroxymethyl) cyclopropane has been obtained in three steps from commercially available cis-2-butene-1,4-diol (75% overall yield) and used to prepare a number of all-1,2,3-trisubstituted cycloprop
- Schill, Heiko,De Meijere, Armin,Yufit, Dmitry S.
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- Direct Allylation of Active Methylene Compounds with Allylic Alcohols by Use of Palladium/Phosphine-Borane Catalyst System
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The C?C bond formation between active methylene compounds and allylic alcohols has been newly developed by using a palladium complex as a catalyst together with a phosphine-borane ligand. The best phosphine-borane ligand for this direct allylation has bee
- Shimizu, Aika,Hirata, Goki,Onodera, Gen,Kimura, Masanari
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p. 1954 - 1960
(2018/04/11)
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- Visible-Light-Mediated Reactions of Electrophilic Radicals with Vinyl and Allyl Trifluoroborates
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Visible-light photoredox catalysis enables the vinylation and allylation of electrophilic radicals with readily available potassium trifluoroborate reagents. The processes show good functional group compatibility, and mechanistic and computational studies
- Fernandez Reina, Daniel,Ruffoni, Alessandro,Al-Faiyz, Yasair S. S.,Douglas, James J.,Sheikh, Nadeem S.,Leonori, Daniele
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p. 4126 - 4130
(2017/06/19)
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- Enantiopure hydroxymethylated cycloalkenols as privileged small molecular multifunctional scaffolds for the asymmetric synthesis of carbocycles
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Enantiopure hydroxymethylated cycloalkenols bearing a quaternary stereocenter have been synthesized by a Pybox mediated enantioselective desymmetrization method. The synthesized cycloalkenols serve as starting precursors for the construction of several ch
- Kumar, Rajan,Rej, Rohan Kalyan,Halder, Joydev,Mandal, Haridas,Nanda, Samik
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p. 498 - 512
(2016/06/06)
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- COMPOUNDS USEFUL AS MODULATORS OF TRPM8
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The present invention includes compounds useful as modulators of TRPM8, such as compounds of Formulae (Ia), (Ib) and (Ic), and the subgenus and species thereof; personal products containing those compounds; and the use of those compounds and the personal products, particularly the use of increasing or inducing chemesthetic sensations, such as cooling or cold sensations.
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Paragraph 0534
(2016/03/29)
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- Palladium(II)-Catalyzed Allylic C H Oxidation of Hindered Substrates Featuring Tunable Selectivity Over Extent of Oxidation
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The use of Oxone and a palladium(II) catalyst enables the efficient allylic C H oxidation of sterically hindered α-quaternary lactams which are unreactive under known conditions for similar transformations. This simple, safe, and effective system for C H activation allows for unusual tunable selectivity between a two-electron oxidation to the allylic acetates and a four-electron oxidation to the corresponding enals, with the dominant product depending on the presence or absence of water. The versatile synthetic utility of both the allylic acetate and enal products accessible through this methodology is also demonstrated.
- Xing, Xiangyou,O'Connor, Nicholas R.,Stoltz, Brian M.
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supporting information
p. 11186 - 11190
(2016/07/06)
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- Total Synthesis and Configurational Assignment of AscospiroketalA
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The total synthesis of the marine fungus-derived natural product ascospiroketal is described. This concise synthesis relies on a unique AgI-promoted tandem cascade cyclization that provides direct access to the correctly configured tricyclic core of the natural product from a linear precursor. The synthesis of candidate stereostructures of ascospiroketalA allowed for the confident assignment of both the relative and absolute stereochemistry of this unusual octaketide.
- Chang, Stanley,Hur, Soo,Britton, Robert
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p. 16646 - 16653
(2015/11/09)
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- [Copper(phenanthroline)(bisisonitrile)]+-Complexes for the Visible-Light-Mediated Atom Transfer Radical Addition and Allylation Reactions
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A series of heteroleptic [Cu(phenantroline)(bisisonitrile)]+-complexes was synthesized, and their structural, spectroscopic, and electrochemical properties were investigated. The new copper(I) complexes were employed as photoredox-catalysts in the visible-light-mediated atom transfer radical addition (ATRA). Especially, [Cu(dpp)(binc)]BF4 (6a-BF4)(dpp = 2,9-diphenyl-1,10-phenanthroline; binc = bis(2-isocyanophenyl) phenylphosphonate) proved to be highly active owing to an enhanced excited-state lifetime compared to the commonly employed [Cu(dap)2]Cl (1-Cl)(dap = 2,9-di(p-anisyl)-1,10-phenanthroline). Furthermore, the catalyst could be applied to allylation reactions with trimethylallylsilane under mild visible-light photoredox conditions.
- Knorn, Matthias,Rawner, Thomas,Czerwieniec, Rafa?,Reiser, Oliver
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p. 5186 - 5193
(2015/09/15)
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- An improved solvent-free system for the microwave-assisted decarboxylation of malonate derivatives based on the use of imidazole
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A comparative study of the thermal and microwave-assisted decarboxylation of a series of mono- and disubstituted monohydrolyzed malonate derivatives has been carried out. It has been found out that in both circumstances the use of imidazole has a profound effect on the success of the reaction. In general terms the assistance of microwave irradiation accelerates the decarboxylation process significantly and, at the same time, permits the use of minored temperatures with respect to the thermal via. It has been also found that both the thermal and the microwave-assisted transformation can be developed under solvent-free conditions.
- Tellitu, Imanol,Beitia, Itziar,Díaz, Marta,Alonso, Argi?e,Moreno, Isabel,Domínguez, Esther
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p. 8251 - 8255
(2015/10/05)
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- Palladium-catalyzed allylation of malonic acid derivatives in heterogeneous systems containing ionic liquids
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Palladium-catalyzed potassium carbonate-assisted reaction between diethyl malonate and allyl acetate in the presence of 1,3-dialkyl-imidazolium ionic liquids (ILs) as solvents or phase transfer catalysts affords major monoallylation product, whereas in the presence of 1,2,3-trialkylimidazolium or quaternary ammonium/phosphonium ILs diallylation product is preferably formed. These procedures are extended to some other CH-acids and allylic acetates.
- Vasil'ev, Andrei A.,Zlotin, Sergei G.
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- Isomerizing ethenolysis as an efficient strategy for styrene synthesis
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A shrinking chain: A bimetallic system consisting of [{Pd(μ-Br)(tBu 3P)}2] and a ruthenium metathesis catalyst has been found to efficiently promote the cross-metathesis between substituted alkenes and ethylene, while continuously migrating the double bond along the alkenyl chain (see scheme). When alkenylarenes, such as the natural products eugenol, safrol, or estragol, were treated with this catalyst under an ethylene atmosphere, they were cleanly converted into the corresponding styrenes and propylene gas. Copyright
- Baader, Sabrina,Ohlmann, Dominik M.,Goossen, Lukas J.
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supporting information
p. 9807 - 9810
(2013/08/23)
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- Pd-catalyzed allylation of CH acids under phase-transfer conditions
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The composition of the products obtained by Pd-catalyzed allylation of diethyl (alkyl)- malonates and ethyl cyanoacetate with allylic acetates under phase-transfer conditions using potassium carbonate or phosphate as bases depended strongly on the nature of the reactants and the ligands used. The highest yields and the fraction of the "linear" regioisomers were achieved in the reactions of prenyl or 3-methylbut-1-en-3-yl acetates in the presence of phosphordiamidite ligands.
- Vasil’ev,Lyubimov,Serebryakov,Davankov,Struchkova,Zlotin
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experimental part
p. 605 - 610
(2011/02/17)
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- Internally Masked Neopentyl Sulfonyl Ester Cyclization Release Prodrugs of Acamprosate, Compositions Thereof, and Methods of Use
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Internally masked neopentyl sulfonyl ester prodrugs of acamprosate, pharmaceutical compositions comprising such prodrugs, and methods of using such prodrugs and compositions thereof for treating diseases are disclosed. In particular, acamprosate prodrugs
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Page/Page column 39-40
(2009/04/24)
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- Leaving group potential of a substituted cyclopentadienyl anion toward oxidative addition
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The facility with which a substituted cyclopentadienyl anion may function as a leaving group for palladium-catalyzed allylation reactions Is demonstrated. Reaction of several allylcyclopentadienyl substrates Is shown. Nucleophilic displacement of carbon w
- Fisher, Ethan L.,Lambert, Tristan H.
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supporting information; experimental part
p. 4108 - 4110
(2009/12/06)
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- Photoactive barbiturate receptors: An ultimate lock-and-key system in which the key unlocks the lock
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(Chemical Equation Presented) Conditional photofragmentation is achieved with binary systems incorporating the isophthaloyl bis-aminopyridine barbiturate recognition motif and dithiane- or trithiane-based photolabile modules, which cleave only in the pres
- Lakkakula, Suman,Mitkin, Oleg D.,Valiulin, Roman A.,Kutateladze, Andrei G.
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p. 1077 - 1079
(2007/10/03)
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- Palladium complexes of phosphine functionalised carbosilane dendrimers as catalysts in a continuous flow membrane reactor
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Phosphine functionalised carbosilane dendrimers have been synthesised and their palladium complexes used as catalysts in the allylic alkylation reaction performed in a continuous flow membrane reactor.
- De Groot, Debby,Eggeling, Eva B.,De Wilde, Janine C.,Kooijman, Huub,Van Haaren, Richard J.,Van Der Made, Alexander W.,Spek, Anthony L.,Vogt, Dieter,Reek, Joost N. H.,Kamer, Paul C. J.,Van Leeuwen, Piet W. N. M.
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p. 1623 - 1624
(2007/10/03)
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- Total synthesis of (+/-)-acetomycin and design of esterase-resistant analogs.
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The synthesis of acetomycin and related analogs was investigated. Acetomycin was synthesized from diethyl allyl(methyl)malonate in 6.5% yield over 18 steps. The total number of steps was improved compared to our previous synthesis; i.e., four steps shorte
- Uenishi,Kobayashi,Komine,Okadai,Yonemitsu,Sasaki,Yamada
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p. 517 - 523
(2007/10/03)
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- 'Propylene spaced' allyl tin reagents: A new class of fluorous tin reagents for allylations under radical and metal-catalyzed conditions
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A new generation of propylene-spaced fluorous allyltin reagents [(Rf(CH2)3)3SnCH2CH=CH2] is described. These succeed in radical allylations where their lower homologs (ethylene-spaced) fail, and they provide improved performance in transition metal catalyzed allylations. The reagents and byproducts are readily separated by simple fluorous-organic liquid-liquid or solid-liquid extractions.
- Curran, Dennis P.,Luo, Zhiyong,Degenkolb, Peter
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p. 2403 - 2408
(2007/10/03)
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- Structure-activity studies of fluoroalkyl-substituted γ-butyrolactone and γ-thiobutyrolactone modulators of GABA(A) receptor function
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Dihydro-2(3H)-furanones (γ-butyrolactones) and dihydro-2(3H)-thiophenones (γ-thiobutyrolactones) containing fluoroalkyl groups at positions C-3, C-4, and C-5 of the heterocyclic rings were prepared. The anticonvulsant/convulsant activities of the compounds were evaluated in mice. Brain concentrations of the compounds were determined and the effects of the compounds on [35S]-tert-butylbicyclophosphorothionate ([35S]TBPS) binding to the picrotoxin site on GABA(A) receptors were investigated. The effects of the compounds on GABA(A) receptor function were studied using electrophysiological methods and cultured rat hippocampal neurons. Fluorination at C-3 results in either subtle or pronounced effects on the pharmacological activity of the compounds. When hydrogens are replaced with fluorines at the methylene carbon of an ethyl group, as in 3-(1,1-difluoroethyl)dihydro-3-methyl-2(3H)-furanone (1), the anticonvulsant actions of the compound are not much changed from those found for the corresponding alkyl-substituted analogue. In marked contrast, fluorination at the methyl carbon of the ethyl group, as in dihydro-3-methyl-3-(2,2,2-trifluoroethyl)-2(3H)-furanone (3), produces a compound having convulsant activity. This convulsant activity seems to be due to an increased affinity of the compound for the picrotoxin site on GABA(A) receptors caused by an interaction that involves the trifluoromethyl group. Results obtained with γ-butyrolactones containing either a 3-(1-trifluoromethyl)ethyl or a 3-(1-methyl-1-trifluoromethyl)ethyl substitutent indicate that the interactions of the trifluoromethyl group with the picrotoxin binding site are subject to both stereochemical and steric constraints. Sulfur for oxygen heteroatom substitution, as in the corresponding γ-thiobutyrolactones, affects the type (competitive, noncompetitive, etc.) of binding interactions that these compounds have with the picrotoxin site in a complex manner. Fluorination of alkyl groups at the C-4 and C-5 positions of γ-butyrolactones having convulsant activity increases convulsant potency.
- Canney, Daniel J.,Lu, Hwang-Fun,McKeon, Ann C.,Yoon, Kong-Woo,Xu, Kun,Holland, Katherine D.,Rothman, Steven M.,Ferrendelli, James A.,Covey, Douglas F.
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- Radical reaction initiated and stereocontrolled by zinc chloride
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The reaction of allyltributyltin with methyl 2-[N-((4S)-4-(1-methylethyl)-2-oxazolidinone-3-carbamoyl)amino]-2-bromoacetate (5 a) was accelerated at -50°C in the presence of AIBN and stopped in the presence of galvinoxyl, indicating that the reaction proceeds through a radical mechanism. The reaction was accelerated dramatically at -78°C in the presence of ZnCl2·OEt2, and the ZnCl2-mediated reaction was stopped in the presence of galvinoxyl. In the presence of 2 equiv ZnCl2·OEt2, the reaction afforded methyl (2R)-2-[N-((4SH-(1-methylethyl)-2-oxazolidinone-3-carbamoyl)amino]-4-pentenoate {6a(R)} with high diastereoselectivity (93:7). Taken together, ZnCl2·OEt2 works as a radical initiator as well as chelating agent.
- Yamamoto, Yoshinori,Onuki, Setsuko,Yumoto, Masatoshi,Asao, Naoki
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p. 765 - 780
(2007/10/03)
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- Reaction of tetracarbonyl(π-allyl)manganese with carbon nucleophiles
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Nucleophilic attack on tetracarbony (π-allyl)manganese takes place at the terminus of the π-system, generating allylated products in 44-95% yield after oxidation. Stabilized nucleophiles (pK(a) 12-20) give mainly bis allylation whereas nonstabilized nucleophiles (pKa 25-35) give mono allylation.
- Vaughan, William S.,Gu, Henry H.,McDaniel, Keith F.
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p. 1885 - 1888
(2007/10/03)
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- Nucleophile Addition an (?-Allyl)palladium-Komplexe: Steuerung des Angriffs am zentralen oder an den terminalen Kohlenstoffatomen durch Liganden
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Keywords: Komplexe mit Kohlenstoffliganden; Ligandeneffekte; Nucleophiler Angriff; Palladiumverbindungen
- Castano, Ana M.,Aranyos, Attila,Szabo, Kalman J.,Baeckvall, Jan-E.
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p. 2767 - 2769
(2007/10/03)
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- Palladium Catalysed Direct Allylation of Pronucleophiles with Allylstannanes
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The reaction of pronucleophiles 1 with allyltributylstannanes in the presence of catalytic amounts of Pd2(dba)3*CHCl3 (4 molpercent) and 1,2-bis(diphenylphosphino)ethane (dppe) (10 molpercent) at room temperature gives the corresponding allylation products in good to high yields.
- Yamamoto, Yoshinori,Fujiwara, Naoya
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p. 2013 - 2014
(2007/10/02)
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- Chelating agents for forming complexes with radioactive isotopes, metal complexes thereof and use thereof in diagnosis and therapy
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The invention relates to compounds having the general formula I STR1 where A if required can contain a functional and/or activated group C for coupling to selectively concentrating compounds or can contain a selectively concentrating compound coupled via
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- Studies on Cyclodepsipeptides - Part I : A Stereoselective Synthesis of C12 Polyketide Unit (C1-C8) Present in Jaspamide and Geodiamolide A-F
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An innovative synthetic protocol to obtain the polyketide C12 chain in an enantiomerically pure form has been developed.
- Rao, A. V. Rama,Gurjar, Mukund K.,Nallaganchu, Bhaskara Rao,Bhandari, Ashok
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p. 7081 - 7084
(2007/10/02)
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- Steric effects in intramolecular [2+2] photocycloaddition of C=C double bonds to cyclohexenones
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The effect of substituents on the mode of approach and the endo/exo ratio in intramolecular [2+2] photocycloaddition reactions were studied.
- Becker,Haddad
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p. 947 - 964
(2007/10/02)
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- Synthetic Studies Relevant to Biosynthetic Research on Vitamin B12. Part 5. Synthesis of (RS)-Ring-B Imide
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Future biosynthetic research on vitamin B12 depends on the synthesis of a family of isobacteriochlorin pigments.A key building block required for this work is 2-(2-methoxycarbonylethyl)-3-methoxycarbonylmethyl-3-methylsuccinimide, usually called the ring-B imide.A practical synthesis of the racemic form of this substance is described which can yield multigramme quantities of product.
- Battersby, Alan R.,Westwood, Steven W.
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p. 1679 - 1688
(2007/10/02)
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- DICOBALTOCTACARBONYL-ALKYNE COMPLEXES AS INTERMEDIATES IN THE SYNTHESIS OF BICYCLOOCTENONES FOR THE SYNTHESIS OF CORIOLIN AND HIRSUTIC ACID
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Treatment of the readily prepared enzynes 12, 21 and 45 with Co2(CO)8 at ca 110 deg C results in high yields (80percent) of substituted bicyclooctenones, that are suitable for straightforward elaboration into coriolin and hirsutic acid precursors.A mechanistic hypothesis to explain the observed stereospecificity is presented.
- Magnus, Philip,Exon, Christopher,Albaugh-Robertson, Pamela
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p. 5861 - 5869
(2007/10/02)
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- REACTIONS OF ORGANOCOBALT COMPLEXES WITH BROMOESTERS: REGIOSPECIFIC SYNTHESIS OF ALLYL- AND CYCLOPROPYLMETHYL-SUBSTITUTED MALONIC AND ACETOACETIC ESTERS
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Allyl(pyridine)cobaloximes RCo(dmgH)2Py (R = allyl) react readily with diethyldibromomalonate, diethylbromomethylmalonate and ethyl 2-bromoacetoacetate to give the corresponding allyl-substituted esters.Transfer of the allyl group occurs with complete rearrangement in all but one cases.Buten-3-yl(pyridine)cobaloximes react with diethylbromomalonate giving cyclopropylmethylmalonic esters.
- Veber, M.,Duong, K.N.-V.,Gaudemer, A.,Johnson, M. D.
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p. 393 - 400
(2007/10/02)
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- Cyclopropanation of Ester Enolates by ?-Allylpalladium Chloride Complexes
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Branched ester enolates react with ?-allylpalladium chloride complexes in the presence of Et3N and HMPA to produce alkylated cyclopropanes.Labeling studies indicate the carbanion attacks the central carbon of the ?-allyl complex.
- Hegedus, Louis S.,Darlington, W.H.,Russell, Charles E.
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p. 5193 - 5196
(2007/10/02)
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- Synthesis of S-(+)-4-methyl-3-heptanone, the principal alarm pheromone of Atta texana, and its enantiomer
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The principal alarm pheromone of Atta texana S-(+)-4-methyl-3-heptanone, and its enantiomer have been prepared synthetically in high optical purity.
- Riley,Silverstein
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p. 1171 - 1174
(2007/10/12)
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