- Nickel-Catalyzed Favorskii-Type Rearrangement of Cyclobutanone Oxime Esters to Cyclopropanecarbonitriles
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A nickel-catalyzed base-promoted rearrangement of cyclobutanone oxime esters to cyclopropanecarbonitriles was developed. The ring opening of cyclobutanone oxime esters occurs at the sterically less hindered side. A base-promoted nickelacyclobutane intermediate, formed in situ, is assumed to be involved in the formation of the product.
- Fang, Ping,Mei, Tian-Sheng,Shuai, Bin
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supporting information
p. 1637 - 1641
(2021/10/02)
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- Preparation method of cibenzoline succinate midbody
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The invention discloses a preparation method of a cibenzoline succinate midbody, relates to a preparation method of the cibenzoline succinate midbody 1-cyanogroup-2,2-diphenyl cyclopropane and belongs to the field of drug chemical synthesis. The preparation method comprises the following steps that an oxidation reaction is generated with benzophenone hydrazone as a raw material and hydrogen peroxide as an oxidizing agent under the presence of a phase transfer catalyst, then diphenyldiazomethane is obtained and directly reacts with acrylonitrile without purification in the reaction system, and the midbody 1-cyanogroup-2,2-diphenyl cyclopropane is obtained. According to the method, the recovery rate is high, operation is easy and convenient, discharging of three wastes is reduced, the production cost of cibenzoline succinate is reduced remarkably, and the method is quite beneficial for industrialized production.
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Paragraph 0015; 0016; 0017; 0018
(2017/12/09)
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- Towards nitrile-substituted cyclopropanes-a slow-release protocol for safe and scalable applications of diazo acetonitrile
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Diazo acetonitrile has long been neglected despite its high value in organic synthesis due to a high risk of explosions. Herein, we report our efforts towards the transient and safe generation of this diazo compound, its applications in iron catalyzed cyclopropanation and cyclopropenation reactions and the gram-scale synthesis of cyclopropyl nitriles.
- Hock, Katharina J.,Spitzner, Robin,Koenigs, Rene M.
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supporting information
p. 2118 - 2122
(2017/07/24)
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- New synthesis of multisubstituted cyanocyclopropanes by the intramolecular SN2 alkylation and 1,3-CC insertion reaction of magnesium carbenoids as the key reactions
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Addition reaction of 1-chlorovinyl p-tolyl sulfoxides derived from ketones and aldehydes with lithium α-cyano carbanions gave nitrile adducts in high to quantitative yields. Treatment of the nitrile adducts derived from acetonitrile with excess i-PrMgCl in THF resulted in the formation of cyanocyclopropanes via the intramolecular SN2 alkylation of the generated magnesium carbenoids. The intermediate of this reaction was proved to be a cyclopropylmagnesium chloride and was reactive with electrophiles to give multisubstituted cyanocyclopropanes. On the other hand, the reaction of the nitrile adducts derived from arylacetonitriles with i-PrMgCl resulted in the formation of 2-arylcyanocyclopropanes by the 1,3-carbon-carbon (1,3-CC) insertion reaction of the generated magnesium carbenoid intermediates. This reaction was found to proceed in a highly stereospecific manner. The key reactions, intramolecular SN2 alkylation and 1,3-CC insertion reaction of the magnesium carbenoids, are the first examples for the reaction of the magnesium carbenoids bearing a nitrile functional group.
- Saitoh, Hideki,Watanabe, Tatsuya,Kimura, Tsutomu,Kato, Yuichi,Satoh, Tsuyoshi
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scheme or table
p. 2481 - 2495
(2012/05/05)
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- Incremental solvation precedes ion-pair separation in enantiomerization of a cyano-stabilized Grignard reagent
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Concerted or stepwise? Ion-pair separation is often proposed as a mechanism for enantiomerization of organolithium reagents in ethereal solvents. But what is the timing of the solvation and bond-cleavage events? Are they concerted, or does one precede the
- Patwardhan, Neeraj N.,Gao, Ming,Carlier, Paul R.
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supporting information; experimental part
p. 12250 - 12253
(2011/12/15)
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- Reactions of diazo compounds with alkenes catalysed by [RuCl(cod)(Cp)]: Effect of the substituents in the formation of cyclopropanation or metathesis products
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The reaction of diazo compounds with alkenes catalysed by complex [RuCl(COd)(Cp)] (cod = 1, 5-cyclooctadiene, Cp = cyclopentadienyl) has been studied. The catalytic cycle involves in the first step the decomposition of the diazo derivative to afford the reactive [RuCl(Cp)I=C(R1)R 2)] intermediate and a mechanism is proposed for this step based on a kinetic study of the simple coupling reaction of ethyl diazoacetate. The evolution of the Ru-carbene intermediate in the presence of alkenes depends on the nature of the substituents at both the diazo N2=C(R 1)R2 (R1, R2 = Ph, H; Ph, CO 2Me; Ph, Ph; C(R1)R2 = fluorene) and the olefin substrates R3(H)C= C(H)R4 (R3, R4 = CO2Et, CO2Et; Ph, Ph; Ph, Me; Ph, H; Me, Br; Me, CN; Ph, CN; H, CN; CN, CN). A remarkable reactivity of the complex was recorded, especially towards unstable aryldiazo compounds and electron-poor olefins. The results obtained indicate that either cyclopropanation or metathesis products can be formed: the first products are favoured by the presence of a cyano substituent at the double bond and the second ones by a phenyl.
- Basato, Marino,Tubaro, Cristina,Biffis, Andrea,Bonato, Marco,Buscemi, Gabriella,Lighezzolo, Filippo,Lunardi, Pamela,Yianini, Chiara,Benetollo, Franco,Del Zotto, Alessandro
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experimental part
p. 1516 - 1526
(2009/09/04)
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- Novel process for the synthesis of class I antiarrhythmic agent (±)-cibenzoline and its analogs
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Synthesis of (±)-cibenzoline and its analogs has been achieved by a simple sequence of reactions. The diaryl cyanoolefin intermediate 3 could be prepared by Knoevenagel condensation of benzophenone with ethylcyanoacetate to form the tetra-substituted olefin intermediate 2 followed by Krapcho deethoxycarbonylation or from β-hydroxynitrile intermediate 2' followed by the elimination of hydroxyl group respectively. The 2,2- diphenylcyclopropanecarbonitrile 4 was synthesized from intermediate 3 by cyclopropanation, which was converted to (±)-2-(2,2-diphenylcyclopropyl)- 2-imidazoline 5 by reaction with ethylenediamine in the presence of a catalytic amount of sulfur. Moreover, the obtained 2-imidazolines were smoothly oxidized to the corresponding imidazoles 6 in good to moderate yields. Copyright Taylor & Francis Group, LLC.
- Gholap, Atul R.,Paul, Vincent,Srinivasan, Kumar V.
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p. 2967 - 2982
(2008/12/22)
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- The first enantioenriched metalated nitrile possessing macroscopic configurationat stability
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Figure presented Magnesium - bromine exchange on enantiopure cyclopropyl bromonitrile 5 at -100°C for 1 min followed by a D2O quench gives the deuterionitrile in 81% ee (retention); additional trapping experiments establish t1/2(rac) = 11.4 h at -100°C. These experiments provide the first glimpse into the stereochemical aspects of Mg-Br exchange. The intermediate formed is the first metalated nitrile demonstrated to possess macroscopic configurational stability.
- Carlier, Paul R.,Zhang, Yiqun
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p. 1319 - 1322
(2007/12/29)
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- Cyclopropane formation via a simple barbier reaction in DMF
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Cyclopropanes are prepared in good yields via magnesium activation of polyhalomethyl compounds (dichlorodiphenylmethane, methyl trichloroacetate, α,α,α-trichlorotoluene, benzal chloride, benzal bromide) in the presence of activated olefins in DMF.
- Oudeyer, Sylvain,Aaziz, Akima,Léonel, Eric,Paugam, Jean Paul,Nédélec, Jean-Yves
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p. 485 - 488
(2007/10/03)
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- Cyclopropane formation by copper-catalysed indirect electroreductive coupling of activated olefins and activated α,α,α-trichloro or gem-dichloro compounds
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Cyclopropanes have been prepared in good yields by indirect electroreductive coupling of activated olefins and activated α,α,α-trichloro or gem-dichloro compounds (Cl3CCO2Me, PhCCl3, Ph2CCl2, PhCHCl2). This process, using a copper complex in catalytic amountss is convenient for the reagent couple activated olefin/activated polyhalide, whatever the reduction potential of each reagent relative to each other. The main advantage of our electrochemical process is that it does not require the use of hazardous, toxic, or not easily prepared reagents like diazocompounds or diazirines.
- Sengmany,Leonel,Paugam,Nedelec
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p. 533 - 537
(2007/10/03)
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- Reactions of tosylhydrazones of benzaldehyde and benzophenone with cyanoalkenes in a basic two-phase system
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Reaction of tosylhydrazones 1a,b with cyanoalkenes 3a,b, carried out in the presence of concentrated aq. sodium hydroxide in dioxane, afforded either cyanocyclopropanes 5, 9 or pyrazoles 13, 14 and 16, 17. The process takes place via generation of diazocompounds 2a,b from 1a,b their [3+2] cycloaddition to 3a,b with the formation of unstable pyrazolines 4, further fate of which depends on the structure of R1 and R2 substituents.
- Jończyk,Wlostowska,Ma?akosza
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p. 2827 - 2832
(2007/10/03)
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- REACTIVITY OF THE ACIDS OF TRIVALENT PHOSPHORUS AND THEIR DERIVATIVES. PART III. THE =P-O- IONS IN REACTION WITH ACTIVATED ALKYL BROMIDES. ATTACK ON BROMINE vs ELECTRON TRANSFER
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The mechanism of reductive debromination in the course of the reaction of sodium dialkyl (diaryl) phosphites as well as the sodium salt of dibenzylphosphine oxide with activated alkyl bromides in THF has been investigated.Probable mechanisms namely SET and X-philic substitution are discussed.The cyclopropyl system was chosen for the study of this reaction.The results of the carried out experiments (unrearranged products, no influence of light) suggest that the cyclopropyl radical intermediate (if it is formed) does not paticipate in the product-determining step ofthe reductive debromination under the action of the =P-O- ions.Key words: Bromocyclopropanes, reductive debromination, dialkyl phosphites, diaryl phosphites, dibenzylphosphine oxide, SET, X-philic substitution.
- Dembkowski, Leszek,Rachon, Janusz
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p. 251 - 262
(2007/10/02)
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- THIONES AS SUPERDIPOLAROPHILES
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According to kinetic measurements,the 1,3-cycloadditions of diphenyl-diazomethane to thioketones are much faster than those to α,β-unsaturated carbonyl compounds and nitriles previously regarded as record dipolarophiles.The primary cycloadducts are tetrasubstituted 1,3,4-thiadiazolines which extrude N2 and furnish thiiranes via thiocarbonyl ylides.
- Huisgen, Rolf,Langhals, Elke
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p. 5369 - 5372
(2007/10/02)
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- The Formation of an Enantiomerically Pure Product of Free Radical Coupling. The Chemistry of Diphenylcarbene in Polycrystalline (S)-(+)-2-Butanol
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Photolysis of 0.1 M diphenyldiazomethane at 77 K or 137 K in solid (S)-(+)-2-butanol gives tertiary alcohol 9 along with other products.Compound 9 was isolated and found to be enantiomerically pure by chiral NMR shift reagents.Compound 9 is formed by reaction of triplet diphenylcarbene with (S)-(+)-2-butanol to give a radical pair which subsequently collapses.The solid-state matrix directs the radical pair collapse with complete retention of configuration.
- Zayas, Jose,Platz, Matthew S.
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p. 7065 - 7069
(2007/10/02)
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- Effect of Temperature and Solvent on the 1,3-Dipolar Cycloaddition of Diazodiphenylmethane with Several Dipolarophiles
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The title reaction is studied with a series of CN- or COOCH3-substituted dipolarophiles.All the reactions obey the second-order rate law.The activation enthalpies and entropies are 44-52 kJ mol-1 and -(129-166) J K-1 mol-1, respectively.The rate constants are insensitive to solvent.The reactivity and product of dimethyl maleate are anomalous.
- Yoshimura, Yosuke,Osugi, Jiro,Nakahara, Masaru
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p. 3325 - 3326
(2007/10/02)
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