- Regioselective palladium-catalysed prenylation of CH acids in the presence of diamidophosphite ligands and potassium carbonate
-
The palladium-catalysed prenylation of CH acids with 3-methylbut-1-en-3-yl or prenyl acetates under phase-transfer conditions affords high yield of the linear regioisomer provided by the use of diamidophosphite ligands.
- Vasil'ev, Andrei A.,Lyubimov, Sergey E.,Serebryakov, Edward P.,Davankov, Vadim A.,Zlotin, Sergei G.
-
-
Read Online
- Syntheses and odor properties of optically active dimethyl octenone and its analogs
-
The optically active isomers of dimethyl octenone, which is used in citrus accords, and its analogs, were synthesized from a common chiral intermediate prepared by the lipase-catalyzed desymmetrization of prochiral diol. The results of an olfactory evaluation of the prepared isomers are also reported.
- Kawasaki, Masashi,Shimizu, Momo,Kuroyanagi, Saki,Shishido, Yoshiaki,Komiyama, Tsuyoshi,Toyooka, Naoki
-
-
Read Online
- Copper-Catalyzed Aerobic Oxidative Azo-Ene Cyclization
-
A copper-catalyzed aerobic oxidative azo-ene cyclization has been developed. The developed CuI/DMAP/O2 system efficiently facilitates the aerobic oxidation of ene-containing hydrazides to azo compounds, which undergo azo-ene cyclizations for the synthesis of oxazolidinones. In addition, the present approach enables the synthesis of lactams, as well as a nitroso-ene cyclization. Preliminary mechanistic studies revealed that two carbonyl groups were essential for the successful azo-ene cyclization and that a concerted mechanism might be plausible for this azo-ene cyclization. (Figure presented.).
- Kim, Junsu,Lee, Da Hye,Kim, Jinho
-
supporting information
p. 4728 - 4733
(2021/09/09)
-
- A General Photocatalytic Route to Prenylation
-
Prenylation is an essential reaction on which nature relies to modify properties of molecules and build terpenoids, but remains a challenging chemical reaction. Aiming to capitalize on recent advances in photocatalysis to easily and cleanly generate a broad range of carbon based radicals, we have developed a prenyl transfer reagent that is captured by transiently generated radicals. The reagent can be made in bulk, is bench stable, and broadly applicable such that it can be used with existing photocatalytic methods with very few changes to reaction conditions. Ultimately, this provides a true drop-in solution for prenylation, expanding the scope of substrates that can be readily prenylated.
- Rathnayake, Manjula D.,Weaver, Jimmie D.
-
supporting information
p. 1433 - 1438
(2019/06/13)
-
- Computational and experimental studies on copper-mediated selective cascade C-H/N-H annulation of electron-deficient acrylamide with arynes
-
An efficient and convenient copper-mediated method has been developed to achieve direct cascade C-H/N-H annulation to synthesize 2-quinolinones from electron-deficient acrylamides and arynes. This method highlights an emerging but simple strategy to transform inert C-H bonds into versatile functional groups in organic synthesis to provide a new method of synthesizing 2-quinolinones efficiently. Mechanistic investigations by experimental and density functional theory (DFT) studies suggest that an organometallic C-H activation via a Cu(iii) intermediate is likely to be involved in the reaction.
- Chen, Chao,Hao, Yu,Zhang, Ting-Yu,Pan, Jin-Long,Ding, Jun,Xiang, Heng-Ye,Wang, Man,Ding, Tong-Mei,Duan, Abing,Zhang, Shu-Yu
-
supporting information
p. 755 - 758
(2019/01/21)
-
- Photoredox Synthesis of Arylhydroxylamines from Carboxylic Acids and Nitrosoarenes
-
Hydroxylamines are found in biologically active compounds and serve as building blocks for the preparation of nitrogen-containing molecules. Here the direct conversion of carboxylic acids into the corresponding alkylhydroxylamines using organo-photoredox catalysis is reported. The process relies in the generation of alkyl radicals via photoinduced oxidation-decarboxylation and their following reaction with nitrosoarenes. We have successfully applied this method to the late-stage modification of complex and biologically active acids and applied it in novel radical cascade processes.
- Davies, Jacob,Angelini, Lucrezia,Alkhalifah, Mohammed A.,Sanz, Laia Malet,Sheikh, Nadeem S.,Leonori, Daniele
-
supporting information
p. 821 - 830
(2018/01/11)
-
- Kinetic benchmarking reveals the competence of prenyl groups in ring-closing metathesis
-
A series of prenyl-containing malonates are kinetically benchmarked against the standard allyl-containing congeners using a ruthenium benzylidene precatalyst for ringclosing metatheses. The prenyl grouping is found to be a superior acceptor olefin compared to an allyl group in RCM processes with ruthenium alkylidenes derived from terminal alkenes. The prenyl group is also found to be a highly competent acceptor for a ruthenium alkylidene derived from a 1, 1-disubstituted olefin in a RCM process.
- Bahou, Karim A.,Braddock, D. Christopher,Meye, Adam G.,Savage, G. Paul
-
supporting information
p. 5332 - 5335
(2017/11/07)
-
- Visible-Light-Promoted Oxidative [4 + 2] Cycloadditions of Aryl Silyl Enol Ethers
-
Visible-light-promoted oxidative [4 + 2] cycloadditions of μ,3-unsaturated silyl enol ethers have been developed to efficiently and diastereoselectively construct polycyclic skeletons under mild conditions. The diastereoselectivities were dependent on the stereoconfiguration of silyl enol ether, substitutions on the link, as well as electric properties of substitutions on aryl rings. The intermediates could be trapped by TEMPO, oxygen or methanol. Mechanistic studies indicated the reaction was initiated by one-electron oxidation of the silyl enol ether.
- Yang, Bo,Lu, Zhan
-
p. 7288 - 7300
(2016/08/30)
-
- DIHYDROOROTIC ACID DEHYDROGENASE INHIBITOR
-
The present invention provides a novel dihydroorotic acid dehydrogenase inhibitor which is applicable to various diseases. When used as an active ingredient, a compound represented by formula (I): (wherein X represents a halogen atom, R1 represents a hydrogen atom, R2 represents an alkyl group containing 1 to 7 carbon atoms, R3 represents -CHO, and R4 represents -CH2-CH=C(CH3)-R0 (wherein R0 represents an alkyl group containing 1 to 12 carbon atoms which may have a substituent on the terminal carbon and/or on a non-terminal carbon, etc.)), an optical isomer thereof or a pharmaceutically acceptable salt thereof has a high inhibitory effect on dihydroorotic acid dehydrogenase and can be used as an immunosuppressive agent, a therapeutic agent for rheumatism, an anticancer agent, a therapeutic agent for graft rejection, an antiviral agent, an anti-H. pylori agent, a therapeutic agent for diabetes or the like.
- -
-
Paragraph 0307; 0308
(2015/04/15)
-
- Catalytic intramolecular carbonyl-ene reaction with ketones: Evidence for a retro-ene process
-
The ene-process with unsaturated ketones was catalyzed by Lewis acids such as bismuth or indium triflates. Unlike aldehydes, the reverse ene-process occurs with ketones, resulting in incomplete conversions, as shown by control experiments and analysis by ESI-MS.
- Tremel,Iacobucci,Massi,Olivero,Gal,Du?ach
-
p. 7453 - 7458
(2015/09/02)
-
- Palladium-catalyzed allylation of malonic acid derivatives in heterogeneous systems containing ionic liquids
-
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.
-
-
- Calcium-catalyzed cycloisomerization of enynes
-
A cycloisomerization of enynes with a benign calcium catalyst is presented exploring a complementary reactivity to that usually found in transition and noble metal-catalyzed reactions. Thereby, a systematic investigation of the π-activation of alkynes with reactive carbocations has been realized and ketones of various ring sizes were easily accessed. We are certain that these basic investigations will pave the way for the elaboration of further reactions based on the reaction principles discovered in the area of noble metal catalysis. Copyright
- Meyer, Vera J.,Fu, Liang,Marquardt, Fabian,Niggemann, Meike
-
supporting information
p. 1943 - 1947
(2013/08/23)
-
- Controlling 6-endo-selectivity in oxidation/bromocyclization cascades for synthesis of aplysiapyranoids and other 2,2,6,6-substituted tetrahydropyrans
-
A cascade, composed of (i) oxovanadium(V)-catalyzed oxidation of bromide by tert-butyl hydroperoxide and (ii) stereoselective 6-endo-bromocyclization, affords 3-bromo-2-aryl-2,6,6-trimethyltetrahydropyrans from styrene-type tertiary alkenols in synthetically useful yields. (E)-Alkenols add the bromo- and the alkoxy substituent anti-selectively across the double bond, indicating a bromonium ion-mechanism for the ring closure. 6-endo-control of the alkenol cyclization thereby arises from the polar effect of the aryl substituent. Two methyl substituents bound to the alkene terminus are not similarly able to favor 6-endo-cyclization, because strain arising from methyl group repulsion, as the bromonium-activated π-bond and the hydroxyl oxygen approach, directs bromocyclization of tertiary prenyl-type substrates toward tetrahydrofuran formation. A hexasubstituted bromotetrahydropyran prepared from the oxidation/bromocyclization cascade served as starting material for synthesis of racemic aplysiapyranoid A, in a sequence of free radical and polar functional group interconversion.
- Brücher, Oliver,Bergstr??er, Uwe,Kelm, Harald,Hartung, Jens,Greb, Marco,Svoboda, Ingrid,Fuess, Hartmut
-
supporting information; experimental part
p. 6968 - 6980
(2012/09/07)
-
- Synthesis of methaprogerol analogs
-
Novel synthetic approaches towards analogs of methaprogerol, the efficient wound healing drug, were developed. Several hitherto unknown compounds obtained exhibited in vivo activity similar to methaprogerol. 2-(3-Dimethylaminopropyl)- 5-methylhex-4-enoic acid enhanced the efficacy of the treatment of diseases of various etiologies and different organ injuries by transplantation of mesenchymal stem cells (MSC) and MSC-derived cardiomyoblasts.
- Kryshtal,Zhdankina,Konoplyannikov,Tartakovsky,Serebryakov,Smirnov,Konoplyannikova,Agaeva,Zlotina
-
p. 253 - 258
(2013/06/05)
-
- Pd-catalyzed allylation of CH acids under phase-transfer conditions
-
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
-
experimental part
p. 605 - 610
(2011/02/17)
-
- Angularly fused triquinanes from linear substrates through trimethylenemethane diyl [2 + 3] cycloaddition reaction
-
Angularly fused triquinanes were synthesized from linear dienes and phenyl(propynyl)iodonium salt through trimethylenemethane (TMM) diyl mediated [2 + 3] cycloaddition reaction. TMM diyl intermediates were obtained from alkylidene carbenes generated from reactions of alkynyliodonium salts with nucleophiles.
- Lee, Hee-Yoon,Jung, Yongsik,Yoon, Yeokwon,Kim, Byung Gyu,Kim, Yeonjoon
-
supporting information; experimental part
p. 2672 - 2674
(2010/08/22)
-
- Zinc-mediated alkylation and acylation of 1,3-dicarbonyl compounds
-
1,3-Dicarbonyl compounds undergo smooth allylation, benzylation, propargylation, and acylation with halides using metallic zinc in DMF at 60 °C to afford the corresponding allyl, benzyl, 2-propynyl, and acylated 1,3-diesters in good yields. In the case of cyclic 1,3-diketones, the corresponding enol ethers are obtained as sole products instead of C-alkylation.
- Yadav,Reddy, B. V. Subba,Mishra, Anand Kumar
-
experimental part
p. 280 - 281
(2010/09/05)
-
- Composition of the cloacal gland secretion of tuatara, Sphenodon punctatus
-
The lipophilic content of the cloacal gland secretion of the tuatara (Sphenodon punctatus) was investigated. GC/EI-MS Analysis of CH2Cl2 extracts of the secretions revealed triacylglycerols as major glandular constituents. Twelve major medium-chain fatty acids were found to be conjugated to glycerol in different combinations, resulting in complex mixtures. These acids were identified by transesterification and subsequent derivatization of natural samples, and their structures were verified by synthesis. The natural glycerides contain predominantly three of the following acids: octanoic (A), (E)- and (Z)-oct-4-enoic (B and C, resp.), (4E,6Z)-octa-4,6-dienoic (tuataric acid;D), (R)-2,6-dimethylheptanoic (E), (R)-2,6-dimethylhept-5-enoic (F), (Z)-dec-4-enoic (G), (4Z,7Z)-deca-4,7-dienoic (H), (R)-3,7-dimethyloct-6-enoic (I), (R)-4,8-dimethylnon-7-enoic (J), (2R,6S)-2,6,10-trimethylundec-9-enoic (K), and (2R,5E)-2,6,10-trimethylundeca-5,9-dienoic acids (L). Several additional acids, occurring in trace amounts only, were tentatively identified by MS. The elucidation of the absolute configuration of the acids was performed by GC on chiral phases. Individual tuatara show specific mixtures of glycerides with up to 100 components. The individual mixtures may permit individual recognition because the bouquets seem to be stable over years.
- Flachsbarth, Birte,Fritzsche, Matthias,Weldon, Paul J.,Schulz, Stefan
-
experimental part
p. 1 - 37
(2010/04/23)
-
- A novel synthesis of the north west portion of Lasonolide A - An anticancer macrolide using Claisen rearrangement
-
A simplified analogue of Lasonolide A (C23-C35 side chain) was synthesized using Fujisawa's stereoselective variant of the Ireland Claisen ester rearrangement.
- Kar, Paramita,Rao,Nagaiah,Gurjar
-
-
- Catalytic deallylation of allyl- and diallylmalonates
-
Substituted allylmalonates undergo the selective C-C bond cleavage in the presence of triethylaluminum and a catalytic amount of nickel and ruthenium phosphine complexes, resulting in the loss of the allyl moiety and formation of monosubstituted malonates. Comparison of reactivity of the nickel and ruthenium complexes showed that the use of the former is general with respect to the structure of the substituted allylmalonates, and the activity of the latter depended on the substitution pattern of the double bond of the allylic moiety. The smooth deallylation may encourage the use of the allyl group as a protective group for the acidic hydrogen in malonates. Copyright
- Necas, David,Tursky, Matyas,Kotora, Martin
-
p. 10222 - 10223
(2007/10/03)
-
- Synthesis of derivatives of prenylacetic acids by reactions of alkyl malonate, cyanoacetate, and acetoacetate with alkylating reagents in ionic liquids
-
A method for the synthesis of carboxylic acid derivatives containing one or two - CH2CHn(Me)CHn+1CH2 - fragments (n = 0, 1) was developed. The method is based on the alkylation of (di)alkyl malonates, cyanoacetates, and acetoacetates with acyclic prenyl halides in ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate and tetrafluoroborate. For the ambident ethyl acetoacetate anion, the reactions with prenyl halides devoid of a double bond in the allylic position relative to the halogen atom carried out in the ionic liquids give mixtures of C- and O-alkylation products, while in the case of allylic prenyl halides, only C-alkylation products are formed. The reactions of ethyl 2-geranylmalonate and 2-geranylacetoacetate with bromocyclohexane and 1-chloro-3-dimethylaminopropane in ionic liquids provided derivatives of pharmacologically active geranylacetic acids. The product yields are higher than those in molecular organic solvents. The ionic liquids were recovered and reused in the alkylation.
- Kryshtal,Zhdankina,Zlotin
-
p. 652 - 658
(2007/10/03)
-
- Alkylation of malonic and acetoacetic esters in an ionic liquid
-
1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) has been used as a recyclable medium in the alkylation of malonic and acetoacetic esters with alkyl, benzyl and prenyl halides.
- Kryshtal, Galina V.,Zhdankina, Galina M.,Zlotin, Sergei G.
-
-
- Iridium complex-catalyzed allylic alkylation of allylic esters and allylic alcohols: Unique regio- and stereoselectivity
-
An iridium complex was found to be an efficient catalyst for allylic alkylation of allylic esters with a stabilized carbon nucleophile. Highly regioselective alkylation at the substituted allylic terminus was achieved. The catalytic activity and regioselectivity were affected by the ligand used. The reaction of (E)-2-alkenyl acetates or 1-substituted 2-propeny acetates with dialkyl sodiomalonate in the presence of a catalytic amount of [Ir(COD)Cl]2/P(OPh)3 (P/Ir = 1-2) gave a product alkylated at the substituted allylic terminus in 95-99% selectivity. Construction of a quaternary carbon center is possible by this methodology. The reaction of 1,1-dialkyl-2-propenyl acetates gave a product alkylated at the disubstituted allylic terminus exclusively. (E)-2-Alken-1-ol could be successfully used as a substrate. The products alkylated at the substituted allylic terminus were obtained in 93-99% selectivity. A 31P NMR study of the reaction of [Ir(COD)Cl]2 with P(OPh)3 revealed that a catalytically active species is a monophosphite species. The π-acceptor property of P(OPh)3 promotes a carbonium ion character at the substituted allylic terminus and directs the nucleophilic attack to this position. The stereochemistry of the allyl system affected the regioselectivity. In contrast to the reaction of (E)-2-alkenyl acetates, the reaction of (Z)-2-alkenyl acetates gave a product alkylated at the unsubstituted allylic terminus predominantly. This shows that the regioselectivity of the alkylation of the syn π-allyl iridium intermediate is different from that of the anti π-allyl iridium intermediate. (Z)- Selective allylic alkylation of (Z)-2-alkenyl esters is also possible by iridium catalysis.
- Takeuchi, Ryo,Kashio, Mikihiro
-
p. 8647 - 8655
(2007/10/03)
-
- Highly selective allylic alkylation with a carbon nucleophile at the more substituted allylic terminus catalyzed by an iridium complex: An efficient method for constructing quaternary carbon centers
-
The selective construction of quaternary carbon centers, which are frequently found in natural products, is essential to many syntheses. A new method relying on the iridium complex [Ir(cod)Cl]2 as the catalyst can be used for the allylic alkylation of acyclic compounds 1. The products are obtained in yields between 70 and 85% and with a selectivity of 100%, cod = cyclooctadiene.
- Takeuchi,Kashio
-
p. 263 - 265
(2007/10/03)
-
- Trapping of translocated radicals by tetrathiafulvalene radical cation
-
Aryl radicals are generated by electron transfer from tetrathiafulvalene to arenediazonium salts.The aryl radicals are translocated into alkyl radicals which undergo a C-S or C-C bond formation to tetrathiafulvalene radical cation, depending on the nucleophilicity/electrophilicity of the translocated carbon radical.
- Murphy, John A.,Roome, Stephen J.
-
p. 1349 - 1358
(2007/10/02)
-
- Biosynthesis of (+)-epicubenol
-
Incubation of [6-2H]FPP (14a) with epicubenol synthase isolated from Streptomyces sp. LL-B7 gave epicubenol (1c) labeled at D-9 as established by 2H NMR. These results confirm the involvement of a predicted 1,2-hydride shift in the mechanism of formation of 1.
- Cane, David E.,Tandon, Manish
-
p. 5355 - 5358
(2007/10/02)
-
- Steric effects in intramolecular [2+2] photocycloaddition of C=C double bonds to cyclohexenones
-
The effect of substituents on the mode of approach and the endo/exo ratio in intramolecular [2+2] photocycloaddition reactions were studied.
- Becker,Haddad
-
p. 947 - 964
(2007/10/02)
-
- Intramolecular reactions of allyloxy radicals featuring six-centred transition states; regiochemistry and stereochemistry
-
Intramolecular free-radical reactions of allyloxy radicals to form tetrahydropyrans and cyclopentanols have been studies; the cyclopentanols form stereoselectively with trans disposition of groups about the ring-forming bond.
- Begley,Housden,Johns,Murphy
-
p. 8417 - 8430
(2007/10/02)
-
- Barbiturate assay, tracers, immunogens, antibodies and kit
-
The present invention is directed to a fluorescence polarization immunoassay for barbiturates, to the various components needed for preparing and carrying out such an assay, and to methods of making these components. Specifically, tracers, immunogens and antibodies are disclosed, as well as methods for preparing them and a reagent kit containing them. The tracers and the immunogens are made from substituted barbiturate compounds. A fluorescein moiety is included in the tracer, while a poly(amino acid) forms a part of the immunogen. The assay is conducted by measuring the degree of polarization retention of plane-polarized light that has been passed through a sample containing antiserum and tracer.
- -
-
-
- Allylation of Active Methylene Compounds with Allyl Oxime Carbonates Catalyzed by Pd(0)
-
Allylation of active methylene compounds catalyzed by a palladium(0)-phosphine system took place highly stereoselectively by employing allyl oxime carbonates as the allylating reagent.
- Suzuki, Osamu,Hashiguchi, Yoshiharu,Inoue, Seiichi,Sato, Kikumasa
-
p. 291 - 294
(2007/10/02)
-
- Etude de l'allylation, catalysee par le nickel, d'enolates stables, par les ethers et les alcools allyliques
-
The allylation of stable enolates derived from diethyl malonate and ethyl cyanoacetate by a variety of aliphatic or aromatic allylic ethers and by allylic alcohols, under nickel catalysis, was investigated.The influence of ligands, solvents and temperature was studied.
- Alvarez, Eleuterio,Cuvigny, Therese,Julia, Marc
-
p. 199 - 212
(2007/10/02)
-
- On the Regio- and Stereoselectivity of Bu4N-Catalyzed Allylic Alkylation
-
Bu4N has been found to catalyze the alkylation of allylic carbonate with malonate anion.The reaction proceeds with good regioselectivity, the nucleophile attacking predominantly at the carbon where the leaving group was attached.Retention of configuration of the double bond during the course of reaction was observed.Alkylation of methyl (Z)-5-carbomethoxy-1-cyclohexen-3-yl carbonate with sodium salt of dimethyl malonate yielded dimethyl ((Z)-5-carbomethoxy-1-cyclohexen-3-yl)malonate in a highly stereoselective fashion, and a net retention of configuration at the center undergoing substitution is thus established.On the basis of regio- and stereochemical results, a reaction pathway involving an ?-allyliron complex has been suggested.
- Xu, Yuanyao,Zhou, Bo
-
p. 974 - 977
(2007/10/02)
-
- Influence du cuivre sur la substitution des enolates stables par divers halogenures allyliques
-
The allylic substitution, by a variety of allylic halides, of stable enolates derived from diethyl malonate, ethyl cyanoacetate, ethyl acetoacetate and acetylacetone has been investigated.The yields and regioselectivity of these reactions are strongly influenced by cuprous ions (and their ligands).
- Cuvigny, Therese,Julia, Marc
-
p. 121 - 138
(2007/10/02)
-
- SUBSTITUTIONS CATALYSEES AU NICKEL D'ACETATES ET DE SULFONES ALLYLIQUES
-
The allylic substitution of stable enolates derived from diethyl malonate, ethyl cyanoacetate, ethyl benzylsulfonylacetate, bis(benzenesulfonyl)methane and sodium p-toluenesulfinate by a variety of allylic esters and sulfones has been investigated.Suitable ligands and reaction conditions have been found to ensure high yields, and in some cases considerable control of the regioselectivity of the reaction.
- Cuvigny, Therese,Julia, Marc
-
p. 383 - 408
(2007/10/02)
-
- Synthesis of 2,3-Secopyrethroids
-
Some 2,3-secopyrethroids, viz. 3-phenoxybenzyl 2-alkyl-5-methylhex-4-enoates and 2-alkylpent-4-enoates (VI a-l) have been synthesized starting from diethyl malonate, employing simple reactions like alkylation, decarboethoxylation and transesterification.These esters exhibit insecticidal activity against musca domestica and adult Aedes aegyptii.
- Randad, R. S.,Kulkarni, G. H.
-
p. 1085 - 1087
(2007/10/02)
-
- ETUDE DE LA REGIOSELECTIVITE DE LA SUBSTITUTION DES CARBANIONS PAR DES DERIVATIVES ALLIQUES CATALYSEE AU PALLADIUM. OBTENTION SELECTIVE DE COMPOSES A CARBONE QUATERNAIRE
-
The influence of the leaving groups, carbanions and ligands on ?-allylpalladium has been investigated in the substitution of primary or tertiary terpene derivatives.Conditions have been found under which the substitution takes place essentially at one or the other end of the allylic system.This provides a new and convenient way to obtain compounds with quaternary carbon atoms, which has been exemplified by the synthesis of 3,3-dimethyl-4-pentenenitrile.
- Cuvigny, Therese,Julia, Marc,Rolando, C.
-
p. 395 - 414
(2007/10/02)
-
- An Investigation of the Thermal Decomposition of the Methohydroxides and Methodeuterio-oxides of Some 5-N,N-Dimethylaminopent-1-enes
-
The base-catalysed thermal decomposition of a number of quaternary bases of the type (R1)2C=CH(R2)2C(R3)2CH2N+Me3X- (R1 = H, Me; R2 = H, 2H; R3 = H, 2H, Me; X = OH, O2H) has been investigated.It is shown that the reaction is initiated by attack of base (OH-, O2H-, ylide) on an allylic proton or .A mechanism for the reaction is suggested.
- Cocker, Wesley,Geraghty, Niall W. A.,McMurry, T. Brian H.,Shannon, Patrick V. R.
-
p. 2245 - 2254
(2007/10/02)
-
- ALKYLATIONS ALLYLIQUES CATALYSEES AU NICKEL
-
Stable enolates such as diethyl malonate enolate can be smoothly substituted by allylic acetates (or sulfones) in the presence of nickel complexes.Sulfinate ions convert allylic acetates into sulfones.
- Cuvigny, Therese,Julia, Marc
-
p. C21 - C24
(2007/10/02)
-
- PALLADIUM-CATALYZED REACTION OF ALLYLIC AMMONIUM BROMIDES WITH NUCLEOPHILES
-
The reactions of allylic triethylammonium bromides and dimethylsulfonium bromide with carbon nucleophiles were catalyzed by tetrakis(triphenylphosphine)palladium to afford olefinic esters and ketones.
- Hirao, Toshikazu,Yamada, Naoto,Ohshiro, Yoshiki,Agawa, Toshio
-
p. 409 - 414
(2007/10/02)
-