- Lanthanide Silylamide-Catalyzed Synthesis of Pyrano[2,3- b]indol-2-ones
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A lanthanide silylamide-catalyzed tandem reaction of isatins, diethyl phosphite, and 2,3-diarylcyclopropenones has been developed. A series of pyrano[2,3-b]indol-2-ones were synthesized in high yields. The cooperation of the Lewis acidity of the lanthanide center and the Bronsted basicity of the N(SiMe3)2 anion may be the key factor affecting the catalytic activity of lanthanide amides.
- Chen, Qifa,Teng, Yue,Xu, Fan
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supporting information
p. 4785 - 4790
(2021/06/28)
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- Fully Substituted Conjugate Benzofuran Core: Multiyne Cascade Coupling and Oxidation of Cyclopropenone
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An unprecedented C═C double bond cleavage of cyclopropenone and dioxygen activation by multiyne cascade coupling has been developed. This chemistry provides a novel, simple, and efficient approach to synthesize fully substituted conjugate benzofuran derivatives from simple substrates under mild conditions. The density functional theory (DFT) calculations reveal that the unique homolytic cleavages of cyclopropenone and molecular oxygen are crucial to the success of this reaction.
- Yao, Liangliang,Hu, Qiong,Bao, Li,Zhu, Wenjing,Hu, Yimin
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supporting information
p. 4971 - 4975
(2021/06/30)
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- Iron-Catalyzed One-Step Synthesis of Isothiazolone/1,2-Selenazolone Derivatives via [3+1+1] Annulation of Cyclopropenones, Anilines, and Elemental Chalcogens
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Described herein is the one-step synthesis of isothiazolone/1,2-selenazolone derivatives via [3+1+1] cycloaddition of cyclopropenone derivatives, anilines, and elemental chalcogens. The cascade reaction involves the C?S, C?N, and N?S bond formation along with the cleavage of C?C bond. Both anilines and cyclopropenones are tolerated and give the corresponding products in 28–73% yields. (Figure presented.).
- Wang, Hongchen,Yan, Rulong
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supporting information
(2021/12/22)
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- Catalytic Asymmetric (3 + 3) Cycloaddition of Oxyallyl Zwitterions with α-Diazomethylphosphonates
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The unique structure of oxyallyls represents a significant challenge for their catalytic asymmetric applications. Herein, an unprecedented chiral imidodiphosphoric acid-catalytic enantioselective (3 + 3) cycloaddition between oxyallyl zwitterions generate
- Liu, Yan,Peng, Xian,Peng, Yungui,She, Rui,Zhou, Xin
-
supporting information
p. 7295 - 7300
(2021/10/01)
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- Cascade Ring-Opening Dual Halogenation of Cyclopropenones with Saturated Oxygen Heterocycles
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Represented is a CuX2- or I2-promoted ring-opening dual halogenation of cyclopropenones with saturated oxygen heterocycles, providing an efficient method for the synthesis of 3-haloacrylates. The ring-opening reaction enables the construction of two C–X (X = Cl, Br, or I) bonds and a C–O bond as well as the cleavage of two C–O bonds and a C–C bond in a single step. This protocol is highly atom economical, has an excellent substrate scope, and exhibits the ability for gram-scale reaction.
- Gao, Wen-Xia,Huang, Xiao-Bo,Liu, Miao-Chang,Miao, Wei-Hang,Wu, Hua-Yue,Zhou, Yun-Bing
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supporting information
p. 9425 - 9430
(2021/12/14)
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- Rh(III)-Catalyzed [3 + 3] Annulation Reaction of Cyclopropenones and Sulfoxonium Ylides toward Trisubstituted 2-Pyrones
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A new Rh(III)-catalyzed [3 + 3] annulation reaction between cyclopropenones and β-ketosulfoxonium ylides has been reported, enabling metal carbene insertion to access a wide range of trisubstituted 2-pyrones with moderate to excellent yields via C-C single-bond cleavage, in which sulfoxonium ylides serve as potential safe precursors of metal carbenes. This reaction occurred under redox-neutral conditions with a broad substrate scope.
- Zhou, Peng,Yang, Wei-Tao,Rahman, Anis Ur,Li, Guigen,Jiang, Bo
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p. 360 - 366
(2019/11/14)
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- Thianthrenation-enabled α-arylation of carbonyl compounds with arenes
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The Pd-catalyzed α-arylation of carbonyl compounds with simple arenes enabled by site-selective thianthrenation has been demonstrated. This onepot process using thianthrenium salts as the traceless arylating reagents features mild conditions and a broad substrate scope. In addition, this protocol could also tolerate the heterocyclic carbonyl compounds and complex bioactive molecules, which is appealing for medicinal chemistry.
- Huang, Yu-Hao,Nie, Xiao-Xue,Wang, Peng
-
supporting information
p. 7716 - 7720
(2020/11/02)
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- Pentaphenylmethylbenzene-containing difluorine monomer, preparation method and application thereof in polyaryletherketone functional membranes
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The invention relates to a pentaphenylmethylbenzene-containing difluorine monomer, a preparation method and application thereof in polyaryletherketone functional membranes, and belongs to the technical field of polymer materials and preparation thereof. T
- -
-
Paragraph 0041; 0044
(2018/09/08)
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- Organocatalytic Regiodivergent C?C Bond Cleavage of Cyclopropenones: A Highly Efficient Cascade Approach to Enantiopure Heterocyclic Frameworks
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Here a highly efficient cascade approach is reported that combines a cycloaddition reaction with a regioselective strain-release process to afford diverse heterocyclic frameworks through bifunctional catalysis. The cooperation of hydrogen-bonding network activation and a regiodivergent strain-assisted effect is the key to promoting this complex chemical transformation, leading to the generation of two different ring systems in high yields with excellent stereoselectivities. The reaction proceeded by a mechanism involving a “spring-loaded” intermediate with switchable C?C bond cleavages achieved by controllable ring-strain release. This reaction was also amenable to gram scale synthesis with only 0.1 mol % catalyst loading.
- Cao, Jian,Fang, Ran,Liu, Jin-Yu,Lu, Hong,Luo, Yong-Chun,Xu, Peng-Fei
-
supporting information
p. 18863 - 18867
(2018/11/23)
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- Organocatalyzed [3 + 2] Annulation of Cyclopropenones and β-Ketoesters: An Approach to Substituted Butenolides with a Quaternary Center
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An unprecedented organocatalyzed [3 + 2] annulation of cyclopropenones and β-ketoesters has been developed. This reaction provides a direct approach to highly substituted butenolides with a quaternary center in moderate to good yields. The preliminary mechanism study verified that the enol intermediate is crucial to the reaction outcome and the intermolecular esterification and intramolecular Michael addition process were involved.
- Li, Xuanyi,Han, Chunhua,Yao, Hequan,Lin, Aijun
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supporting information
p. 778 - 781
(2017/03/01)
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- Development of a catalytic platform for nucleophilic substitution: Cyclopropenone-catalyzed chlorodehydration of alcohols
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Cyclopropenone makes the switch: 2,3-Bis-(p-methoxyphenyl)cyclopropenone is a highly efficient catalyst for the chlorodehydration of 20 diverse alcohol substrates (see scheme; X=Cl). With oxalyl chloride as catalytic activator, this nucleophilic substitution proceeded through cyclopropenium-activated intermediates and resulted in complete stereochemical inversion in substrates with chiral centers.
- Vanos, Christine M.,Lambert, Tristan H.
-
supporting information; experimental part
p. 12222 - 12226
(2012/02/02)
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- Efficient synthesis of substituted polyarylphthalimides via cycloaddition of cyclopentadienones with 2-bromomaleimide
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Functionalized tetraarylphthalimides or diarylphthalimides fused with an acenaphthene moiety have been prepared in one step from 2-bromomaleimide and tetraarylcyclopentadienones (tetracyclones) or 7,9-diaryl-8H- cyclopentacenaphthylene-8-ones (acecyclones
- Vanel, Rémi,Berthiol, Florian,Bessières, Bernard,Einhorn, Cathy,Einhorn, Jacques
-
supporting information; experimental part
p. 1293 - 1295
(2011/07/07)
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- Synthesis and structures of crystalline solvates formed of pyridinium N-phenoxide (Reichardt's-type) betaine dyes and alcohols
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Four new betaine dyes of the Reichardt's type featuring two tolyl substituents in different attachment (2-4) or being an analogous 1-naphthyl derivative (5) have been synthesized and described with reference to their negative solvatochromism. The dinaphth
- Kurjatschij, Sandra,Seichter, Wilhelm,Weber, Edwin
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scheme or table
p. 1465 - 1477
(2010/09/17)
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- Predicting the UV-vis spectra of tetraarylcyclopentadienones: Using DFT molecular orbital energies to model electronic transitions of organic materials
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(Chemical Equation Presented) Tetraphenylcyclopentadienone, due to its intrinsically low HOMO-LUMO gap, has been suggested as a valuable repeat unit in conducting polymers for nanoscale electronics. The HOMO and LUMO of tetraphenylcyclopentadienone appear
- Potter, Robert G.,Hughes, Thomas S.
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p. 2995 - 3004
(2008/09/19)
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- Synthesis of heterosubstituted hexaarylbenzenes via asymmetric carbonylative couplings of benzyl halides
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Asymmetric carbonylative couplings of benzyl halldes have been shown to give heterosubstituted 1,3-diarylacetones In moderate to high yields. These asymmetric ketones were converted via Knoevenagel condensations to tetraarylcyclopentadienones, and further
- Potter, Robert G.,Hughes, Thomas S.
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p. 1187 - 1190
(2008/01/04)
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- Hammett analysis of photodecarbonylation in crystalline 1,3-diarylacetones
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(Chemical Equation Presented) The relative quantum yields and chemical efficiencies of crystalline p,p′-disubstituted 1,3-diphenyl-2-propanones with 4-MeO, 4-Me, 4-F, 4-CF3, and 3,4-diMeO groups were determined by parallel irradiation of polycrystalline samples. Variations in quantum yields that span a factor of 4 are analyzed in terms of the effects of substituents on the stability of the benzylic radical. All solid-state reactions proceeded with 100% chemoselectivity and in >95% chemical yield.
- Resendiz, Marino J. E.,Garcia-Garibay, Miguel A.
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p. 371 - 374
(2007/10/03)
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- Synthesis of 2-methyl-4, 6-diaryl-1, 2, 3-triazinones via diarylcyclopropenones
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2-Methyl-4,6-bis(4-substituted-phenyl)-1,2,3-triazin-5(2H)-ones 9a-d were prepared from the coressponding cyclopropenones 4a-d in a similar fashion as described by us previously. One of the the structure of 9b was established by an X-ray analysis.
- Matsumoto, Kiyoshi,Okada, Akihiro,Girek, Tomasz,Ikemi, Yukio,Kim, Jong Chul,Hayashi, Naoto,Yoshida, Hiroshi,Kakehi, Akikazu
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p. 325 - 328
(2007/10/03)
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- Kinetic Study of Carbonylation of α-Bromo-p-xylene with Iron Pentacarbonyl by Phase-Transfer Catalysis
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The reaction kinetics of the carbonylation of α-bromo-p-xylene (BrCH2C6H4CH3, BX) with iron pentacarbonyl (Fe(CO)5) by phase-transfer catalysis was studied in an organic solvent/alkaline solution. The concentration of tetra-n-butylammonium bromide ((n-C4H9)4NBr, TBAB), NaOH, NaBr, aqueous volume and temperature were evaluated to achieve the optimum reaction condition. The reaction behavior was discussed by the apparent reaction-rate constants for BX and bis(p-methylbenzyl) ketone ((p-CH3C6H4CH2)2CO, BMBK), respectively, and the relationship of consumption of BX and Fe(CO)5. The product distributions of BX with Fe(CO)5 on various reactions conditions were measured. The activation energies was obtained at TBAB = 1.24 and 0 mmol as Well.
- Wu, Ho-Shing,Tan, Wen-Han
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p. 604 - 610
(2007/10/03)
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- New Electrochemical Synthesis of Ketones from Organic Halides and Carbon Monoxide
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The dissolution of a stainless steel anode provides catalytic nickel species which enable the efficient synthesis of ketones by electrolysis of organic halides in DMF in the presence of bipyridine and carbon monoxide.
- Ocafrain, Maitena,Devaud, Marguerite,Troupel, Michel,Perichon, Jacques
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p. 2331 - 2332
(2007/10/02)
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- Incorporation of CO and NO Ligands in the Reaction of Benzyl Bromides with Tetrabutylammonium Tricarbonylnitrosylferrate
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Reaction of benzyl bromides with tetrabutylammonium tricarbonylnitrosylferrate afforded N-benzylphenylacetamides via incorporation of CO and NO ligands accompanied with dibenzyl ketones.A noticeable substituent effect on the amide-forming reaction was observed.
- Nakanishi, Saburo,Shimizu, Yasuyo
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p. 1925 - 1926
(2007/10/02)
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- A Study of Substituent Effects on Hydrogen-to-Arene Nonbonded Interactions
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The polycyclic aromatic hydrocarbon 9,14-diphenylbenzotriphenylene is strongly twisted due to nonbonded interactions between hydrogen atoms on the polycyclic nucleus and the ? systems of the phenyl groups.Ten derivatives of 9,14-diphenylbenzotriphen
- L'Esperance, Robert P.,Engen, Donna Van,Dayal, Rajeev,Pascal, Robert A.
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p. 688 - 694
(2007/10/02)
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- The Preparation and Characterization of Substituted Pentaphenylcyclopentadienyl Ligands, Their Precursors, and Complexes of Iron
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The synthesis and characterisation by infrared, 1H and 13C n.m.r. and mass spectroscopy of the compounds C5Ph4(p-C6H4R)X (R=H, Me, But; X=OH, Br, H), C5Ph4-n(p-C6H4Me)nO (n=1, 2, 4), C5Ph5-n(p-C6H4Me)nX (n= 2, 3; X=OH, Br) and C5Ph4(p-C6H4R)Fe(
- Field, Leslie D.,Ho, Kathy M.,Lindall, Charles M.,Masters, Anthony F.,Webb, Alison G.
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p. 281 - 291
(2007/10/02)
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- Metallic Nickel-Mediated Synthesis of Ketones by the Reaction of Benzylic, Allylic, Vinylic, and Pentafluorophenyl Halides with Acid Halides
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Metallic nickel was investigated as a convenient coupling reagent for the synthesis of ketones by the reaction of benzylic, allylic, vinylic, and pentafluorophenyl halides with acid halides at 85 deg C in glyme.A variety of benzylic ketones with functional groups including halogen, cyano, methoxycarbonyl, and hydroxycarbonyl groups were prepared in good yields by this method.The reaction was demonstrated to proceed via organonickel halide intermediates formed by the smooth oxidative addition of benzylic and acyl halides to metallic nickel, which were trapped with electron-deficient olefins. (?-Allyl)nickel halides, prepared in situ at 85 deg C from allylic halides and the nickel, also worked for the preparation of ketones.Vinylic and pentafluorophenyl halides but not alkyl halides reacted with acid halides to give the corresponding ketones in moderate yields.
- Inaba, Shin-ichi,Rieke, Reuben D.
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p. 1373 - 1381
(2007/10/02)
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- IRON PENTACARBONYL MEDIATED COUPLING OF BENZYL HALIDES TO KETONES UNDER MILD PHASE TRANSFER CONDITIONS.
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In a two-phase system (saturated aqueous calcium hydroxide, tetrabutylammonium sulfate, dichloromethane, iron pentacarbonyl) benzyl bromides are readily carbonylated to dibenzyl ketones ; α-α' dibromoorthoxylene yields the o-quinodimethane iron tricarbonyl cmplex 8.It is inferred that the reactions proceed through transient generation of the tetracarbonyl ferrate dianion.
- Tanguy, Guy,Weinberger, Bernd,Abbayes, Hevre des
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p. 5529 - 5532
(2007/10/02)
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- ACTIVATED METALLIC NICKEL IN PREPARATION OF SYMMETRICAL 1,3-DIARYLPROPAN-2-ONES FROM BENZYLIC HALIDES AND OXALYL CHLORIDES
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Oxidative addition of benzylic halides to nickel in the metallic state followed by insertion of carbon monoxide generated from alkyl oxalyl chlorides proceeded smoothly to give symmetrical 1,3-diarylpropan-2-ones in moderate yields.
- Inaba, Shin-ichi,Rieke, Reuben D.
-
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- Micellar Systems as ''Supercages'' for Reactions of Geminate Radical Pairs. Magnetic Effects
-
The photochemistry of dibenzyl ketone (DBK) and other molecules capable of producing benzyl radicals and substituted benzyl radicals has been investigated in micellar systems.The cage effect (percent of unscavengeable radical pairs produced by photolysis) was measured under a variety of conditions, and the results are compared with those obtained in homogeneous organic solvents.For example, parameters such as mean occupancy of ketone, detergent type and concentration, O2 concentration, additives, temperature, applied magnetic field, and pressure have been varied and investigated as to their influence on the magnitude of cage effect.In addition to modifying its environment, structural modification of the DBK by incorporation of 2H and 13C isotopes, hydrophobic groups, and heavy atoms was performed to investigate the impact of these variations on the cage effect in micellar systems.Isotopic substitution of 2H or 13C leads to results on both the quantum yields for reactions and on the percent cage that were consistent with expectations of magnetic isotope effects.Hydrophobic groups substituted in the 4-position of DBK were found to cause a substantial increase in the cage effect and yet retain the magnetic-field-dependent character found in the parent DBK.Incorporation of Br in the 4-position of DBK was found to enhance the cage effect but at the same time cause the cage effect to become magnetic field independent.Substitution of α-naphthyl for phenyl in DBK also produced magnetic-field-independent behavior, in addition to a dramatic decrease in the efficiency of photolysis.
- Turro, Nicholas J.,Weed, Gregory C.
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p. 1861 - 1868
(2007/10/02)
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- Self-Termination and Electronic Spectra of Substituted Benzyl Radicals in Solution
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Several substituted benzyl radicals have been generated in liquid cyclohexane by the photolysis of symmetrically substituted dibenzyl ketones.The rate constants for self-termination to substituted bibenzyls, and absorption spectra of the transient radicals, have been measured by optical modulation spectroscopy.The termination rates are generally well described by the von Smoluchowski equation with a spin factor of 1/4.Deviations are discussed in terms of steric retardation and the unreliability of the estimated reaction diameters of radicals with bulky substituent groups.Absorption spectra of the three monomethyl-, the three monochloro-, two dichloro-, and the three monomethoxybenzyl radicals demonstrate the influence of the substituents on the energy levels of the benzyl system.
- Claridge, Rodney F. C.,Fischer, Hanns
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p. 1960 - 1967
(2007/10/02)
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- Polycyclic Aromatic Compounds: Part V - A Convenient Synthesis of a New Class of Bis-ethers
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The dienophilic character of bis-acetylenic ether (IV) is studied and a new series of bis-ethers (VI, VIII and IX) are obtained by the condensation of IV with various cyclopentadienones.
- Bandyopadhyay, T. K.,Bhattacharya, A. J.
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p. 620 - 622
(2007/10/02)
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- Ketone-derived Peroxides. Part I. Synthetic Methods.
-
Study of the reactivity of peroxides derivable from ketones by reaction with hydrogen peroxide has required reexamination of preparative methods.Conditions for obtaining five known peroxides from cyclohexanone and the new 1-(1-hydroxycyclohexyldioxy)-1-(1-hydroperoxycyclohexyldioxy)cyclohexane (10) are carefully defined.An improved general method for obtaining cyclic diperoxides (3,3,6,6-tetrasubstituted 1,2,4,5-tetraoxans) (6) has been developed and used to obtain new diperoxides from dibenzyl ketone, di-(4-methylbenzyl) ketone and 2,2-dimethylcyclohexanone whereas indan-2-one and 5,7-dihydro-6H-dibenzocyclohepten-6-one yield the corresponding triperoxides (1,2,4,5,7,8-hexoxonans) (7) and 1,5-diphenylpentan-3-one yields bis-(1-hydroperoxy-1-phenethyl-3-phenylpropyl) peroxide (5k).Ozonolysis of appropriate alkenes has been used to obtain new cyclic diperoxides formally related to 4'-methylacetophenone, propiophenone and deoxybenzoin.
- McCullough, Kevin J.,Morgan, Alistair R.,Nonhebel, Derek C.,Pauson, Peter L.,White, Graham J.
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p. 601 - 628
(2007/10/02)
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- Ketone-derived Peroxides. III. Decompositions of Cyclic Diperoxides derived from Dialkyl Ketones
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The decompositions of diperoxides from acetone, pentan-3-one, 1,5-diphenylpentan-3-one, pinacolone, benzyl methyl ketone and dibenzyl ketone have been studied.The yield of ketone decreases in this series, from 68percent with acetone to 1-2percent with dibenzyl ketone, i.e. with the increasing stability of the more stable radical fragment.The major products from the decompositions of diperoxides from the dibenzyl ketone and di(p-methylbenzyl) ketone were bibenzyl and 4,4'-dimethylbibenzyl respectively formed through coupling of benzyl radicals; crossover experiments showed that this was primarily an out-of-cage process.Most of the peroxides gave significant yields (5-20percent) of esters formed by an in-cage reaction between the alkyl radical and diacyl peroxide generated from decomposition of the biradical formed in the initial O-O bond homolysis of the peroxide.
- McCullough, Kevin J.,Morgan, Alistair R.,Nonhebel, Derek C.,Pauson, Peter L.
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p. 651 - 676
(2007/10/02)
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