- Dearomatisation of 1- and 2-cyanonaphthalene through nucleophilic conjugate addition
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Conjugate nucleophilic addition of organolithium compounds to 1- and 2-cyanonaphthalene is described for the first time. The dearomatisation is carried out in the presence of HMPA and leads to functionalised dihydronaphthalenes. The nucleophiles used incl
- Andújar Sánchez, Carmen M.,Iglesias, Ma José,López Ortiz, Fernando
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- A phosphine-free, heterogeneous palladium-catalyzed atom-efficient carbonylative cross-coupling of triorganoindiums with aryl halides leading to unsymmetrical ketones
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The first phosphine-free heterogeneous palladium-catalyzed carbonylative cross-coupling of aryl halides with triorganoindiums has been developed that proceeds smoothly under 1 or 2.5 atm of carbon monoxide in THF at 68 °C and provides a general and powerful tool for the synthesis of various valuable unsymmetrical ketones with high atom-economy, good yield, and recyclability of the catalyst. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
- You, Shengyong,Xiao, Ruian,Liu, Haiyi,Cai, Mingzhong
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p. 13862 - 13870
(2017/11/27)
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- P -Selective (sp2)-C-H functionalization for an acylation/alkylation reaction using organic photoredox catalysis
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p-Selective (sp2)-C-H functionalization of electron rich arenes has been achieved for acylation and alkylation reactions, respectively, with acyl/alkylselenides by organic photoredox catalysis involving an interesting mechanistic pathway.
- Pandey, Ganesh,Tiwari, Sandip Kumar,Singh, Bhawana,Vanka, Kumar,Jain, Shailja
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p. 12337 - 12340
(2017/11/20)
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- A phosphine-free, atom-efficient cross-coupling reaction of triorganoindiums with acyl chlorides catalyzed by immobilization of palladium(0) in MCM-41
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The first phosphine-free heterogeneous palladium(0)-catalyzed cross-coupling of triorganoindiums with acyl chlorides has been developed that proceeds smoothly in THF at 68 °C and provides a general and powerful tool for the synthesis of various valuable aryl ketones and α,β-acetylenic ketones with high atom-economy and high yield. This phosphine-free heterogeneous palladium(0) catalyst can be easily prepared from commercially available reagents and recovered by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.
- Miao, Jiankang,Huang, Bin,Liu, Haiyi,Cai, Mingzhong
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p. 42570 - 42578
(2017/09/11)
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- DIHYDROIMIDAZOTHIAZOLE DERIVATIVES
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Compounds of formula (I): or pharmaceutically acceptable salts thereof, exhibit 5-HT1A agonism in addition to noradrenaline reuptake inhibition and optionally also 5-HT reuptake inhibition are useful for the treatment of obesity.
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Page/Page column 39
(2008/06/13)
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- Copper-catalysed aerobic oxidation of alcohols using fluorous biphasic catalysis
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A copper(I) catalysed and TEMPO mediated fluorous biphasic oxidation of primary, secondary, allylic and benzylic alcohols with oxygen in the presence of a bipyridine ligand bearing perfluorinated ponytails is described. High chemoselectivities are observed in the oxidation of substituted cyclohexanols (substituted axial cyclohexanols react 6-8 times faster than the corresponding equatorial cyclohexanols).
- Ragagnin, Gianna,Betzemeier, Bodo,Quici, Silvio,Knochel, Paul
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p. 3985 - 3991
(2007/10/03)
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- Reactions d'addition conjuguee d'organolithiens aux acides carboxyliques α, β-insatures
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In THF at -78 deg C, organolithium derivatives and unprotected α,β-unsaturated carboxylic acids give a conjugated addition reaction. Reactions of 1- and 2-napthoic acids with various organolithium derivatives and electrophiles are reported. Two X-ray studies show that the reaction occurs with a good diastereoselectivity: the dilithiated enolate formed as an intermediate adds the electrophile exclusively via the face opposite to that of the organolithium. A study of the 1H NMR spectra of the products obtained shows that these compounds adopt a preffered conformation in solution. The protonolysis of the intermediate enolate by trifluoroacetic acid in an inverted mode gives rise to the formation of 1,2-disubstituted dihydronapthalenes. With acyclic α,β-unsaturated carboxylic acids, the diastereoselectivity of the reaction is marginal. With secondary butyllithium, the protonolysis of the intermediate enolates gives a 1,4-addition and an average diastereoselectivity. Reaction of phenylpropiolic acid with butyllithium gives rise to the formation of a produst resulting from a trans addition to the triple bond; the organolithium derivative adds in α to the carboxylic group. - Key words: 1,4-addition reactions; carboxylic acids; organolithium derivatives.
- Mortier, Jacques,Vaultier, Michel,Plunian, Barbara,Sinbandhit, Sourisak
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- A one-flask synthesis of dihydronaphthalenemethanols by directed addition of organolithium reagents to BHA naphthalenecarboxylates
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The 1,4-addition reaction of organolithium reagents with 2,6-bis(tert- butyl)-4-methoxyphenyl naphthalenecarboxylates gave regioselectively substituted dihydronaphthalenecarboxylates in high yields. Successive treatment of the esters with organolithiums in THF, lithium triethylborohydride, methyl iodide, and finally sodium borohydride in methanol, provided vegio- and stereoselectively the corresponding 1,1,2- and 1,2,2-trisubstituted dihydronaphthalenylmethanols in good yields. This one- flask process is constituted from a sequence of five reactions involving a reductive generation of an aldehyde metal enolate from a ketene as the key step.
- Shindo, Mitsuru,Koga, Kenji,Asano, Yasutomi,Tomioka, Kiyoshi
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p. 4955 - 4968
(2007/10/03)
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- Palladium-catalyzed Desulfonylative Carbonylation of Arylsulfonyl Chlorides in the Presence of Titanium Tetraalkoxides
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The carbonylation of arylsulfonyl chlorides with a catalytic amount of tetrakis(triphenylphosphine)palladium(0) in the presence of a titanium tetraalkoxide gives the corresponding esters along with diaryl disulfides.
- Miura, Masahiro,Itoh, Kenji,Nomura, Masakatsu
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