- Monoallylation and benzylation of dicarbonyl compounds with alcohols catalysed by a cationic cobalt(iii) compound
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Monoallylation and monoalkylation of diketones and β-keto esters with allylic and benzylic alcohols catalysed by [Cp*Co(CH3CN)3][SbF6]2(I) are reported. The method does not require any additive and affords regioselective products. The mechanistic investigations were done byin situ1H NMR spectroscopy as well as control experiments. It has been shown that reactions proceedviaη3-allyl complex formation or ally ether intermediate. The alkylation takes placeviaonly ether intermediate. The resulting allylated and alkylated products have been used for the synthesis of eleven new trisubstituted pyrazoles and one pyrazolone.
- Chandra Sau, Mohan,Mandal, Smita,Bhattacharjee, Manish
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p. 9235 - 9245
(2021/03/16)
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- Rhodium/Lewis Acid Catalyzed Regioselective Addition of 1,3-Dicarbonyl Compounds to Internal Alkynes
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Herein we describe an efficient protocol for the regioselective addition of 1,3-dicarbonyl compounds to internal alkynes catalyzed by rhodium/Lewis acid catalysts. The corresponding branched/linear allylic alkylation products could be selectively obtained in good yields. Rh-H species were considered to be generated by direct C-H oxidative addition of 1,3-dicarbonyl compounds with rhodium catalyst with the assistance of Lewis acid. Moreover, a retro-allylic alkylation process was observed in this transformation.
- Zheng, Wei-Feng,Xu, Qiu-Jing,Kang, Qiang
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supporting information
p. 2323 - 2330
(2017/06/30)
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- Construction of All-Carbon Quaternary Centers through Cu-Catalyzed Sequential Carbene Migratory Insertion and Nucleophilic Substitution/Michael Addition
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A Cu-catalyzed three-component cross-coupling reaction of terminal alkyne, α-diazo ester, and alkyl halide has been developed. This transformation involves sequent migratory insertion of copper-carbene and nucleophilic substitution, in which a C(sp)-C(sp3) bond and a C(sp3)-C(sp3) bond are formed successively on a carbenic center. Michael addition acceptors can also be employed instead of alkyl halides that enable Michael addition to be an alternative way to build C(sp3)-C(sp3) bond. This transformation represents a highly efficient method for the construction of all-carbon quaternary centers.
- Wang, Chengpeng,Ye, Fei,Wu, Chenggui,Zhang, Yan,Wang, Jianbo
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p. 8748 - 8757
(2015/09/15)
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- Enantioselective synthesis of 2-arylbicyclo[1.1.0]butane carboxylates
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The rhodium-catalyzed reaction of 2-diazo-5-arylpent-4-enoates can be controlled by the appropriate choice of catalyst and catalyst loading to form either 2-arylbicyclo[1.1.0]butane carboxylates or cyclohexene derivatives. Both products are produced in a
- Qin, Changming,Davies, Huw M. L.
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supporting information
p. 310 - 313
(2013/03/13)
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- Straightforward synthesis of allylated keto esters: The palladium-catalysed haloketone alkoxycarbonylation/allylation domino reaction
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The palladium-catalysed α-chloro ketone methoxycarbonylation and allylic alkylation reactions can be efficiently combined to provide a new catalytic domino reaction. The first, carbonylative, step generates the β-keto ester, which acts as the nucleophile in a subsequent allylation step. The use of allyl phenates in combination with Xantphos ligand are the key features allowing one to obtain the allylated β-keto esters in good yields Copyright
- Wahl, Benoit,Giboulot, Steven,Mortreux, Andre,Castanet, Yves,Sauthier, Mathieu,Liron, Frederic,Poli, Giovanni
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scheme or table
p. 1077 - 1083
(2012/05/20)
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- Ruthenium-bisimine: A new catalytic precursor for regioselective allylic alkylation
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New complexes [Cp*Ru(bisimine)Cl] are active catalysts for the regioselective alkylation of allylic carbonates by soft carbonucleophiles, in favour of the branched isomers. The catalysts can be conveniently prepared in situ from [Cp*Ru(cod)Cl] and a bulky aromatic bisimine.
- Renaud, Jean-Luc,Bruneau, Christian,Demerseman, Bernard
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p. 408 - 410
(2007/10/03)
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- Substituted imidazotriazinones
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The present invention relates to new substituted imidazotriazinones, processes for their preparation, and their use for the production of medicaments, in particular for improving perception, concentration power, learning power and/or memory power.
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- Regiocontrol in palladium-catalysed allylic alkylation by addition of lithium iodide
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Regioselectivity in the palladium-catalysed allylic alkylation of 1-arylprop-2-enyl acetates [ArCH(OAc)CH=CH2] or (E)-3-phenylprop-2-enyI acetate (PhCH=CHCH2OAc) with sodium enolates of soft carbon nucleophiles is controlled by addition of a catalytic amount of lithium iodide to give lienar products [(E)-ArCH=CHCH2Nu] exclusively; their branch isomers [ArCH(Nu)CH=CH2] were not detected.
- Kawatsura, Motoi,Uozumi, Yasuhiro,Hayashi, Tamio
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p. 217 - 218
(2007/10/03)
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- Manganese(III)-based oxidative freeradical reaction of α-allyl-β-keto ester with molecular oxygen
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Oxidative reactions of α-allyl-β-keto esters 5 with Mn(OAc)3·2H2O give the δ-hydroxy-β-,γ-unsaturated-α-keto esters 6 in good yields. The mechanism of this reaction is discussed.
- Ohshima, Takashi,Sodeoka, Mikiko,Shibasaki, Masakatsu
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p. 8509 - 8512
(2007/10/02)
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- Copper(I) promoted C-C bond forming reactions: direct activation of allyl alcohols
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Allylic alcohols, acetates, carbonates and chlorides can be activated by copper(I) salts towards nucleophilic substitution by carbon nucleophiles under relatively mild conditions.
- Baruah, Jubaraj B.,Samuelson, Ashoka G.
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p. C57 - C60
(2007/10/02)
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- Allylic Carbonates. Efficient Allylating Agents of Carbonucleophiles in Palladium-Catalyzed Reactions under Neutral Conditions
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Allylation of β-keto esters or malonates was carried out in good yields under neutral conditions by using allylic carbonates in the presence of palladium-phospine catalyst.Although simple ketones, esters, nitriles, and sulfones hardly react with allylic carbonates, α-alkenyl or α-aryl ketones, esters, nitriles, and sulfones were also allylated by using palladium-bis(diphenylphosphino)ethane catalyst under neutral conditions.
- Tsuji, Jiro,Shimizu, Isao,Minami, Ichiro,Ohashi, Yukihiro,Sugiura, Teruo,Takahashi, Kazuhiko
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p. 1523 - 1529
(2007/10/02)
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- NEW SYNTHESIS OF CYCLOPENTENOL AND SPIRODECANOL DERIVATIVES VIA INTRAMOLECULAR PHOTO-OXETANE FORMATION
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Cyclopentenol and spirodecanol derivatives accessible to natural products were synthesized in moderate yield by the irradiation of olefinic β-keto esters followed by treatment with sodium hydride.
- Kim, Tong Hei,Hayase, Yoshio,Isoe, Sachihiko
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p. 1421 - 1424
(2007/10/02)
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- FACILE PALLADIUM CATALYZED DECARBOXYLATIVE ALLYLATION OF ACTIVE METHYLENE COMPOUNDS UNDER NEUTRAL CONDITIONS USING ALLYLIC CARBONATES
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Palladium catalyzed decarboxylative allylation of active methylene compounds proceeded under mild neutral conditions using allylic carbonates, which are much more reactive than allylic acetates or phenoxides used commonly in the reaction.
- Tsuji, Jiro,Shimizu, Isao,Minami, Ichiro,Ohashi, Yukihiro
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p. 4809 - 4812
(2007/10/02)
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