- Mild Diazo Transfer Reaction Catalyzed by Modified Clays
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A very mild method for the preparation of various 2-diazo-1,3-carbonyl compounds in the presence of environmentally attractive solid acids such as clays in a heterogeneous manner in moderate to good yield is reported.
- Rianelli, Renata De S.,De Souza, Maria Cecilia B. V.,Ferreira, Vitor F.
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- Vibrational normal modes of diazo-dimedone: A comparative study by Fourier infrared/Raman spectroscopies and conformational analysis by MM/QM
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The 2-diazo-5,5-dimethyl-cyclohexane-1,3-dione (3) was synthesized and the FT-IR/Raman spectra were measured with the purpose of obtain a full assignment of the vibrational modes. Singular aspects concerning the -C{double bond, long}N{double bond, long}N oscillator are discussed in view of two strong bands observed in the region of 2300-2100 cm-1 in both, Infrared and Raman spectra. The density functional theory (DFT) was used to obtain the geometrical structure and for assisting in the vibrational assignment joint to the traditional normal coordinate analysis (NCA). The observed wavenumbers at 2145 (IR), 2144(R) are assigned as the coupled ν(N{double bond, long}N) + ν(C{double bond, long}N) vibrational mode with higher participation of the N{double bond, long}N stretching. A 2188 cm-1 (IR) and at 2186 cm-1 (R) can be assigned as a overtone of one of ν(CC) normal mode or to a combination band of the fundamentals δ(CCH) found at 1169 cm-1 and the δ (CC{double bond, long}N) found at 1017 cm-1 enhanced by Fermi resonance.
- Tellez Soto,Ramos,Rianelli,de Souza,Ferreira
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- 2-azido-1,3-dimethylimidazolinium chloride: An efficient diazo transfer reagent for 1,3-dicarbonyl compounds
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Diazo transfer from 2-azido-1,3-dimethylimidazolinium chloride to 1,3-dicarbonyl compounds has been developed. The -reaction proceeds under mild conditions to give 2-diazo-1,3-dicarbonyl compounds in high yields, which are easily isolated because the by-products are highly soluble in water. Georg Thieme Verlag Stuttgart.
- Kitamura, Mitsuru,Tashiro, Norifumi,Okauchi, Tatsuo
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- Enantioselective Total Synthesis of Chondrosterins I and J by Catalytic Asymmetric Intramolecular Aldol Reaction Using Chiral Diamine Catalyst
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The first enantioselective total synthesis of chondrosterins I and J was accomplished. The synthetic method focuses on an intramolecular aldol reaction through catalytic asymmetric desymmetrization using chiral diamine catalyst. An intensive investigation of this reaction improved the enantiomeric excess up to 92 percent ee. In addition, stereoselective reduction of the ketone moiety efficiently converted chondrosterin I to chondrosterin J.
- Ito, Hisanaka,Kawamoto, Yuichiro,Kobayashi, Toyoharu,Ozone, Daiki
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- Amino-modified Merrifield resins as recyclable catalysts for the safe and sustainable preparation of functionalized α-diazo carbonyl compounds
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Amino-functionalized polystyrene polymers derived from Merrifield resins were prepared and characterized. These basic materials were successfully employed as heterogeneous catalysts in the diazo transfer reaction to 1,3-dicarbonyl compounds, furnishing the corresponding diazo compounds in good to excellent yields and in relatively short reaction times. In addition, the work-up and purification protocols are simple and do not generate large amounts of waste, which are important features in sustainable catalysis and environmentally benign processes. The feasibility of the recovery and reuse of the amino-modified catalysts was also verified, since they can be employed up to five times without appreciable loss of catalytic activity. This straightforward procedure can be readily scaled up to gram scale, enabling the wide application of this method. The synthetic potential was demonstrated through the two-step preparation of 2-amino-N-dodecylacetamide (ANDA), a small molecule of commercial relevance.
- Fantinel, Mariane,Valiati, Nayara,Moro, Pedro A.M.,Sá, Marcus M.
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- Catalyst-Free Electrophilic Ring Expansion of N-Unprotected Aziridines with α-Oxoketenes to Efficient Access 2-Alkylidene-1,3-Oxazolidines
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2-(2-Oxoalkylidene)-1,3-oxazolidine derivatives were synthesized in good to excellent yields regiospecifically through the catalyst-free electrophilic ring expansion of N-unprotected aziridines and the ketene C=O double bond of α-oxoketenes, in situ generated from the microwave-assisted Wolff rearrangement of 2-diazo-1,3-diketones. The ring expansion predominantly underwent an SN1 process and the hydrogen bond decides the (E)-configuration of products. (Figure presented.).
- Chen, Xingpeng,Huang, Zhengshuo,Xu, Jiaxi
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supporting information
p. 3098 - 3108
(2021/05/10)
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- Iridium(III)-Catalyzed C(3)-H Alkylation of Isoquinolines via Metal Carbene Migratory Insertion
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An Ir(III)-catalyzed C(3)-H alkylation of N-acetyl-1,2-dihydroisoquinolines with diverse acceptor-acceptor diazo compounds has been achieved under a single catalytic system via metal carbene migratory insertion. Moreover, further synthetic transformations of the alkylated products such as aromatization, selective decarboxylation, and decarbonylation lead to the formation of several synthetically viable isoquinoline derivatives having immense potentials.
- Jha, Neha,Singh, Roushan Prakash,Saxena, Paridhi,Kapur, Manmohan
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supporting information
p. 8694 - 8698
(2021/11/24)
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- Construction of isoxazolone-fused phenanthridinesviaRh-catalyzed cascade C-H activation/cyclization of 3-arylisoxazolones with cyclic 2-diazo-1,3-diketones
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A Rh(iii)-catalyzed cascade C-H activation/intramolecular cyclization of 3-aryl-5-isoxazolones with cyclic 2-diazo-1,3-diketones was described, leading to the formation of isoxazolo[2,3-f]phenanthridine skeletons. The protocol features the simultaneous one-pot formation of two new C-C/C-N bonds and one heterocycle in moderate-to-good yields with good functional group compatibility. It is amenable to large-scale synthesis and further transformation.
- Hu, Wangcheng,He, Xinwei,Zhou, Tongtong,Zuo, Youpeng,Zhang, Shiwen,Yang, Tingting,Shang, Yongjia
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supporting information
p. 552 - 556
(2021/02/06)
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- Rhodium-Catalyzed [4+2] Annulation of N-Aryl Pyrazolones with Diazo Compounds To Access Pyrazolone-Fused Cinnolines
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An efficient synthesis of novel dinitrogen-fused heterocycles such as pyrazolo[1,2-a]cinnoline derivatives have been accomplished by the rhodium(III)-catalyzed reaction of N-arylpyrazol-5-ones with α-diazo compounds. This reaction proceeds through a cascade C?H activation/intramolecular cyclization with a broad substrate scope. Furthermore, this protocol is successfully extended to the unusual phosphorus-containing α-diazo compounds and cyclic diazo compounds as the cross-coupling partners to deliver the two new kinds of pyrazolo[1,2-a]cinnolinones. The control experiments were performed to reveal insight into the mechanism of this reaction, involving reversible C?H activation, migratory insertion of the diazo compound, and cascade cyclization as the key steps of the transformation. Moreover, gram-scale synthesis and further transformation of the target product demonstrate the synthetic utility of the present protocol.
- Dhole, Sandip,Huang, Wan-Wen,Huang, Ying-Ti,Lin, Chih-Yu,Sun, Chung-Ming
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supporting information
p. 4984 - 4992
(2021/09/28)
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- Rh(II)-mediated one-pot synthesis of dihydrobenzofuran and spiro[2.5]oct-1-ene: Experimental and DFT studies
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This study represents an experimental and computational approach to investigate the rhodium-catalyzed one-pot synthesis of dihydrobenzofuran-4-one (DBF) and spiro[2.5]oct-1-ene (SOE) derivatives. Density functional theory (DFT) calculations were performed at B3LYP and M06-2X level theory. For mechanistic studies, the calculation employing B3LYP/GenECP/LanL2DZ/6-311++G(d,p) level of theory demonstrated that a [3 + 2] cycloaddition reaction between diazo compound and phenylacetylene (PhA) proceeds through a two-step mechanism via a barrierless and highly exergonic process with relative free energy 73.61 kcal/mol to yield the kinetically favored DBF derivatives (50%–62.5%). In contrast, the assemble of SOE derivatives follows [2 + 1] cycloaddition between in situ generated cyclohexane-1,3-dione carbene-2 and PhA, with the potential energy barrier 4.41 kJ/mol. Thermochemistry calculation disclosed that the cycloaddition reactions are spontaneous, and DBF (6a) is thermodynamically more stable than its constitutional isomer SOE (7a) by 42.59 kcal/mol. However, natural bond orbital (NBO), HOMO–LUMO energy gaps (4.62–4.89 eV), dipole moments, polarizability, first-order hyperpolarizability, and global reactivity descriptors were calculated to understand products' structural features. Additionally, Merck Molecular Force Field (MMFF94), followed by the B3LYP level of theory, was applied to predict the relative stability for the various conformations of 6b and 7b. The Boltzmann weighted average 1H chemical shift computed by GIAO-B3LYP/6-311+(2d,p) method and UV-Vis absorption calculated using time-dependent density functional theory (TD-DFT) agree with experimental results. Finally, the synthesis of DBF and SOE derivatives is herein illustrated.
- Bari, Md. Abdul,Hoque, Mohammad Mazharol,Khan, Md. Wahab
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- Taking diazo transfer to water: α-diazo carbonyl compounds from in situ generated mesyl azide
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Mesyl azide generated in situ in aqueous medium converted a range of active methylene substrates into the corresponding diazo compounds in good yields and high purity with no need for chromatographic purification. The products thus obtained are suitable for the subsequent RhII-catalyzed O–H insertions with no need for chromatography in the interim.
- Dar'in, Dmitry V.,Krasavin, Mikhail,Shevalev, Robert M.,Zhmurov, Petr A.
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p. 372 - 373
(2020/06/19)
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- A 'sulfonyl-azide-free' (SAFE) aqueous-phase diazo transfer reaction for parallel and diversity-oriented synthesis
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Diazo transfer reactions are notoriously associated with the use of potentially explosive sulfonyl azides. The first 'sulfonyl-azide-free' (SAFE) protocol for producing diazo compounds from their active-methylene precursors via the Regitz diazo transfer reaction was developed and has displayed a remarkable substrate scope. It can be applied to generating arrays of diazo compounds for further evolution via combinatorial chemistry and a range of scaffold-generating transformations.
- Dar'In, Dmitry,Kantin, Grigory,Krasavin, Mikhail
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supporting information
p. 5239 - 5242
(2019/05/08)
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- A benzoxazine ketone compound and its synthetic method
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The programme discloses chemical field of a benzoxazine ketone compound and its synthetic method, 1) in the reactor to a double-methanone, acetonitrile, toluene sulfonyl azide and alkali metal catalyst, under the conditions of the reaction at room temperature for several hours, filtered, filtrate concentrated by column chromatography separation and purification; ethyl acetate/petroleum ether recrystallization to obtain the intermediate I: 5. 5 - Dimethyl - 2 - diazo - 1, 3 - Cyclohexanedione; 2) in the reactor to joins the aldehyde, amine 0.5 h, then adding the intermediate I, reaction 0.5 h, water/ethyl acetate=2/3 the reaction liquid extraction, taking acetic acid [...] concentrated under reduced pressure, then the TLC separation, to obtain the target of formula II: Wherein R1 can be aryl, substituted aryl, R2 can be hydrogen, C1 - 6 alkyl, C1 - 6 alkoxy, hydroxy. The method of the invention overcomes the oxazine compound and its synthesis the deficiency of the method, the raw material is simple, safe operation, the beneficial effect of the high product purity.
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Paragraph 0030-0035
(2019/01/08)
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- Intrinsically Safe and Shelf-Stable Diazo-Transfer Reagent for Fast Synthesis of Diazo Compounds
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We report a crystalline compound 2-azido-4,6-dimethoxy-1,3,5-triazine (ADT) as an intrinsically safe, highly efficient, and shelf-stable diazo-transfer reagent. Because the decomposition of ADT is an endothermal process (ΔH = 30.3 kJ mol-1), ADT is intrinsically nonexplosive, as proved by thermal, friction, and impact tests. The diazo-transfer reaction based on ADT gives diazo compounds in excellent yields within several minutes at room temperature. ADT is very stable upon >1 year storage under air at room temperature.
- Xie, Shibo,Yan, Ziqiang,Li, Yuanheng,Song, Qun,Ma, Mingming
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p. 10916 - 10921
(2018/09/17)
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- Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds
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Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular SN2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.
- Li, Siqi,Chen, Xingpeng,Xu, Jiaxi
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supporting information
p. 1613 - 1620
(2018/03/07)
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- Synthesis of 3-acyl-5,6-dihydro-1,4-oxathiines through ring expansion of thiiranes
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Synthesis of 3-acyl-5,6-dihydro-1,4-oxathiines has been achieved via reactions of thiiranes and α-diazo-β-1,3-dicarbonyl compounds under microwave and copper sulfate-assisted conditions. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-1,4-oxathiines from readily available thiiranes and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes. The reaction mechanism was also proposed.
- Chen, Xingpeng,Xu, Jiaxi
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supporting information
p. 1651 - 1654
(2017/04/04)
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- Ruthenium Complexes Immobilized on Functionalized Knitted Hypercrosslinked Polymers as Efficient and Recyclable Catalysts for Organic Transformations
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A hypercrosslinked polymer (HCP)-immobilized ruthenium catalyst (HCP–PPh3–Ru) was prepared from benzene and triphenylphosphine (PPh3) through a one-step external cross-linking reaction. The structure and composition of the catalyst were fully characterized by many physicochemical methods. HCP–PPh3–Ru was found to possess high Brunauer–Emmett–Teller (BET) surface area, large pore volume, and low skeletal density. Moreover, the Ru catalyst was also featured some advantages, such as low synthetic cost and good chemical and thermal stability. HCP–PPh3–Ru was then used as a recoverable and effective catalyst for the synthesis of 2,4-diaryl-substituted pyridines from acetophenones, ammonium acetate (NH4OAc) and dimethylformamide (DMF), and the cycloaddition reaction of diazodicarbonyl compounds with olefins to afford dihydrofurans. In addition, a combination of HCP–PPh3–Ru and Amberlyst-15 enabled us to establish a simple protocol for the direct synthesis of carbazole derivatives from diazodicarbonyl compound, alkyl vinyl ether and indole. In these selected reactions, the catalyst was easily recovered and reused several times without significant activity loss. (Figure presented.).
- Jia, Zhifang,Wang, Kewei,Tan, Bien,Gu, Yanlong
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supporting information
p. 78 - 88
(2017/01/14)
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- Amine-mediated synthesis of amides from 1,3-dicarbonyl compounds through a domino diazo transfer/aminolysis process
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The dual role of amines as both catalysts and substrates for the synthesis of diazo compounds or carboxamides from 1,3-dicarbonyl compounds is described herein. In the presence of a suitable diazo transfer agent, primary and cyclic secondary amines act as basic catalysts for the diazo transfer reaction to malonates, β-keto esters, and β-diketones. Depending on the structure of the 1,3-dicarbonyl compound and the nucleophilicity of the amine, the resulting α-diazo-β-keto ester undergoes cleavage of the acyl group to give amides. A multifunctionalized γ-azido-α-diazo-β-keto ester was cleanly prepared in good yields by this one-pot protocol under practical and safe conditions, being employed in a Knoevenagel-type condensation with aromatic aldehydes to give densely functionalized diazo azido compounds. Further treatment of these unsaturated γ-azido-α-diazo-β-keto esters with primary amines readily furnished the corresponding α-azidocinnamamides in high yields, which were used in the synthesis of novel indole-2-carboxamides through the rhodium-catalyzed intramolecular C–H insertion.
- Costin, Taíssa A.,Dutra, Luiz G.,Bortoluzzi, Adailton J.,Sá, Marcus M.
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p. 4549 - 4559
(2017/07/11)
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- Development and Application of a Recyclable High-Load Magnetic Co/C Hybrid ROMP-Derived Benzenesulfonyl Chloride Reagent and Utility of Corresponding Analogues
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The development and application of high-load, recyclable magnetic Co/C hybrid ROMP-derived benzenesulfonyl chloride and analogues is reported. The regeneration and utility of these reagents in the methylation/alkylation of various carboxylic acids is demonstrated via efficient retrieval of the magnetic reagent with a neodymium magnet. Additional reactions employing the analogue sulfonic acid and in situ generated magnetic benzenesulfonyl azide are also reported.
- Faisal, Saqib,Zang, Qin,Maity, Pradip K.,Brandhofer, Agnes,Kearney, Patrick C.,Reiser, Oliver,Grass, Robert N.,Stoianova, Diana,Hanson, Paul R.
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supporting information
p. 2274 - 2277
(2017/05/12)
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- C-H Activation-Based Traceless Synthesis via Electrophilic Removal of a Directing Group. Rhodium(III)-Catalyzed Entry into Indoles from N-Nitroso and α-Diazo-β-keto Compounds
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A distinct C-H activation-based traceless synthetic protocol via electrophilic removal of a directing group is reported, complementing the currently exclusively used nucleophilic strategy. Rh(III)-catalyzed, N-nitroso-directed C-H activation allows the development of a traceless, atom- and step-economic, cascade approach for the synthesis of indole skeletons, starting from readily available N-nitroso and α-diazo-β-keto compounds. Importantly, the cyclization/denitrosation reaction represents a hitherto unobserved reactivity pattern for the N-nitroso group.
- Wang, Jie,Wang, Mingyang,Chen, Kehao,Zha, Shanke,Song, Chao,Zhu, Jin
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supporting information
p. 1178 - 1181
(2016/03/15)
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- Synthesis of Sulfonyl Azides via Lewis Base Activation of Sulfonyl Fluorides and Trimethylsilyl Azide
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A protocol for the efficient conversion of sulfonyl fluorides into sulfonyl azides through Lewis base activation is described. The in situ generated sulfonyl azides are efficient diazo-transfer agents, affording diazo compounds and primary azides in excellent yields.
- Barrow, Andrew S.,Moses, John E.
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supporting information
p. 1840 - 1843
(2016/07/16)
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- Dichlorination of α-Diazo-β-dicarbonyls using (dichloroiodo)benzene
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Abstract α-Diazo-β-dicarbonyl compounds were chlorinated using (dichloro)iodobenzene and an activating catalyst. A broad range of reaction rates was observed, which paralleled the relative stability/nucleo-philicity of the diazo compounds. Acyclic diazocarbonyls reacted faster than cyclics, and β-diketones were much faster to react than β-keto esters or β-diesters. Lewis acid activation was used for the first time, allowing us to overcome instances of poor chemoselectivity. Though the yields ranged from low to good, this chlorination reaction has again proven a mild and effective halogenation strategy.
- Coffey, Keith E.,Murphy, Graham K.
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supporting information
p. 1003 - 1007
(2015/05/20)
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- An efficient synthesis of cycloalkane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using (1-aryl-2-bromoethyl)-dimethylsulfonium bromides: Application to a one-pot synthesis of tetrahydroindol-4(5H)-one
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An efficient synthesis of cyclohexane- and cyclopentane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using sulfonium salts was achieved. The reaction of 1,3-cycloalkanediones with (1-aryl-2-bromoethyl)-dimethylsulfonium bromides and powdered K2CO3 in EtOAc provided the corresponding spirocyclopropanes in high yields. Furthermore, a one-pot synthesis of tetrahydroindol-4(5H)-one from 1,3-cyclohexanedione was achieved using the present protocol and a sequential ring-opening cyclization of spirocyclopropane with a primary amine.
- Nambu, Hisanori,Fukumoto, Masahiro,Hirota, Wataru,Ono, Naoki,Yakura, Takayuki
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p. 4312 - 4315
(2015/06/22)
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- SUBSTITUTED PYRIDINONE COMPOUNDS AS MEK INHIBITORS
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The invention provides novel substituted heterocyclic compounds represented by Formula I and Formula II, or a pharmaceutically acceptable salt, solvate, polymorph, ester, tautomer or prodrug thereof, and a composition comprising these compounds. The compounds provided can be used as inhibitors of MEK and are useful in the treatment of inflammatory diseases, cancer and other hyperproliferative diseases. The invention further provides a method of treatment for inflammatory diseases, cancer and other hyperproliferative diseases in mammals, especially humans.
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Page/Page column 56; 57
(2015/01/07)
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- Diazo transfer reaction to 1,3-dicarbonyl compounds with sulfonyl azides catalyzed by molecular sieves
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A simple and effective heterogeneous catalyst based on zeolite-type materials has been developed for the diazo transfer reaction involving 1,3-dicarbonyl compounds and tosyl azide. α-Diazo carbonyl compounds were obtained under mild conditions in good to high yields using commercial molecular sieve 4A or analogues as the catalyst. The best catalyst was found to be 4A-1000, a synthetic potassium-free nepheline obtained by heating molecular sieve 4A at 1000 C. Characterization of the resulting aluminosilicate by XRD, FTIR and SEM-EDS analysis confirmed the change of the crystal structure. Besides being nontoxic and inexpensive, the heterogeneous catalyst was readily removed by filtration and could be reused at least for four runs without any special treatment.
- Dutra, Luiz G.,Saibert, Cristine,Vicentini, Denice S.,Sá, Marcus M.
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- Metal-triflate-catalyzed synthesis of polycyclic tertiary alcohols by cyclization of γ-allenic ketones
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It has been established that bismuth(III) triflate catalyzes the cyclization of γ-allenic ketones under mild reaction conditions. This reaction allows the selective formation of polycyclic tertiary alcohols from cyclic ketone derivatives. The resulting dienols can engage in stereoselective cycloadditions to efficiently afford complex polycyclic systems. Simply complex: The described catalytic carbonyl-ene reaction is efficiently performed under mild reaction conditions by using only 1 mol % of bismuth(III) triflate, thus affording functionalized molecular scaffolds. Complex polycyclic structures with a defined stereochemistry have been synthesized by using the carbonyl-ene products in a subsequent hydroxy-directed Diels-Alder reaction.
- Diaf, Ilhem,Lemiere, Gilles,Dunach, Elisabet
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supporting information
p. 4177 - 4180
(2014/05/06)
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- Regioselective synthesis of highly functionalized furans through the RuII-catalyzed [3+2] cycloaddition of diazodicarbonyl compounds
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A novel method for the RuII-catalyzed regioselective synthesis of highly functionalized furans from readily available cyclic and acyclic diazodicarbonyl compounds and terminal alkynes is described. The devised protocol offers a straightforward means to the construction of a variety of diverse furan derivatives through powerful cascade processes, including the formation of ruthenium carbenoid, cyclopropenation, ring-opening metathesis, and cyclization. Copyright
- Xia, Likai,Lee, Yong Rok
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p. 3430 - 3442
(2014/06/09)
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- Synthesis of ionic liquid-supported sulfonyl azide and its application in diazotransfer reaction
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The paper describes synthesis of a novel ionic liquid-supported sulfonyl azide and its applications as diazotransfer reagent of active methylene compounds as well as deformylative diazo transfer reagent. The diazo compounds were isolated in excellent yields (82-94%) and high purity. The method offers better separation of product and reagent. This method is experimentally simple and mild, and requires very short reaction time.
- Muthyala, Manoj Kumar,Choudhary, Sunita,Kumar, Anil
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p. 8787 - 8791
(2012/11/07)
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- Ruthenium catalyzed synthesis of enaminones
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The Grubbs first-generation catalyst has been found to be an effective catalyst for the synthesis of enaminones by coupling thioamides with α-diazodicarbonyl compounds. The reaction is successful in converting primary, secondary, and tertiary thioamides into their corresponding enaminones. The reaction is also suitable for the synthesis of chiral enaminones.
- Koduri, Naga Durgarao,Scott, Halee,Hileman, Bethany,Cox, Justin D.,Coffin, Michael,Glicksberg, Lindsay,Hussaini, Syed R.
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supporting information; experimental part
p. 440 - 443
(2012/03/10)
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- Efficient one-pot synthesis of cyclic β-enaminoamides by thermal Wolff rearrangement of cyclic 2-diazo-1,3-dicarbonyls and conversion to uracil derivatives
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This paper describes simple and efficient approaches for the preparation of β-enaminoamides through thermal Wolff rearrangement of cyclic diazodicarbonyls followed by trapping with various amines. The synthesized β-enaminoamides were readily converted into uracil derivatives.
- Neupane, Pratik,Li, Xin,Jung, Jae Hak,Lee, Yong Rok,Kim, Sung Hong
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body text
p. 2496 - 2508
(2012/04/23)
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- Intramolecular hydrogen bonding-assisted cyclocondensation of α-diazoketones with various amines: A strategy for highly efficient Wolff 1,2,3-triazole synthesis
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A catalytic and highly efficient Wolff's cyclocondensation of α-diazoketones with aromatic and aliphatic amines has been realized for the first time by utilizing the strategy of an intramolecular hydrogen bonding-activating carbonyl group. This approach successfully solved the challenging problem of poor condensation efficiency in Wolff 1,2,3-triazole synthesis, and constitutes a powerful method for the synthesis of highly functionalized 1,2,3-triazoles. The Royal Society of Chemistry 2012.
- Wang, Zikun,Bi, Xihe,Liao, Peiqiu,Zhang, Rui,Liang, Yongjiu,Dong, Dewen
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supporting information; experimental part
p. 7076 - 7078
(2012/08/14)
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- Catalyst- and halogen-free regioselective friedel-crafts α-ketoacylations
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Fast, efficient and green! Highly regioselective and efficient catalyst- and halogen-free Friedel-Crafts α-ketoacylation reactions leading to heterocycles functionalized with a very versatile 1,3-diketone moiety are described. The reactions rely on microwave-assisted domino Wolff rearrangement/Friedel-Crafts sequences from 2-diazo-1,3-diketones via transient, highly reactive α-keto ketene intermediates. Copyright
- Mohanan, Kishor,Presset, Marc,Mailhol, Damien,Coquerel, Yoann,Rodriguez, Jean
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supporting information; body text
p. 9217 - 9220
(2012/08/28)
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- 2-Azido-1,3-dimethylimidazolinium salts: Efficient diazo-transfer reagents for 1,3-dicarbonyl compounds
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We have developed the diazo-transfer of 2-azido-1,3-dimethylimidazolinium salts to 1,3-dicarbonyl compounds. 2-Azido-1,3-dimethylimidazolinium chloride (ADMC) was prepared by N-nitrosation of N-aminoguanidine or by the reaction of 2-chloro-1,3-dimethylimidazolinium chloride (DMC) and sodium azide. The corresponding phosphate, ADMP, was isolated as a crystal, and was found to be a stable and safe reagent. Both ADMC and ADMP reacted with 1,3-dicarbonyl compounds under mild conditions to give 2-diazo-1,3-dicarbonyl compounds in high yields, which are easily isolated because the by-products are highly soluble in water. Georg Thieme Verlag Stuttgart.
- Kitamura, Mitsuru,Tashiro, Norifumi,Miyagawa, Satoshi,Okauchi, Tatsuo
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experimental part
p. 1037 - 1044
(2011/06/20)
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- Diazo-transfer reactions to 1,3-dicarbonyl compounds with tosyl azide
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A practical protocol for the large-scale preparation of 2-diazo-1,3-dicarbonyl compounds is described by diazo-transfer reactions with tosyl azide followed by efficient chromatographic purifications on silica gel and/or alumina. Georg Thieme Verlag Stuttgart. New York.
- Presset, Marc,Mailhol, Damien,Coquerel, Yoann,Rodriguez, Jean
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experimental part
p. 2549 - 2552
(2011/10/02)
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- Expeditious synthesis of 2,3,6-trisubstituted 2 H -1,3-oxazin-4(3 H)-ones via the tertiary amine-induced reaction of 2-diazo-3-oxoalkanals and imines under mild conditions
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A series of 2,3,6-trisubstituted 2H-1,3-oxazin-4(3H)-one derivatives were conveniently synthesized in satisfactory to good yields by the reaction of imines with 2-diazo-3-oxoalkanals in the presence of a catalytic amount of a tertiary amine during several seconds under mild condition. Different bases and -diazo - dicarbonyl compounds were also evaluated and a reaction mechanism is proposed. Compared with the corresponding thermal- and photo-induced- reactions, the current method is a metal-free, mild, highly regioselective, and more efficient approach for the synthesis of 2H-1,3-oxazin-4(3H)-one derivatives. Georg Thieme Verlag Stuttgart - New York.
- Qi, Hengzhen,Zhang, Jiantao,Xu, Jiaxi
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supporting information; experimental part
p. 887 - 894
(2011/05/05)
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- 1,3-dipolar cycloaddition of hydrazones with α-oxo-ketenes: A three-component stereoselective entry to pyrazolidinones and an original class of spirooxindoles
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Stereodefined monocyclic, spirobicyclic, and bis-spirotricyclic pyrazolidin-3-ones can be prepared efficiently by a three-component reaction involving a 1,3-dipolar cycloaddition of azomethine imines obtained from hydrazones with α-oxo-ketene dipolarophiles generated in situ. The reaction allows the creation of four covalent bonds and two contiguous chiral quaternary centers with excellent diastereoselectivity in a single catalyst/additive-free, highly atom-economical transformation. From a fundamental point of view, the reaction introduces α-oxo-ketenes as effective dipolarophiles in 1,3-dipolar cycloadditions.
- Presset, Marc,Mohanan, Kishor,Hamann, Marie,Coquerel, Yoann,Rodriguez, Jean
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supporting information; experimental part
p. 4124 - 4127
(2011/10/04)
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- Direct ionic liquid promoted organocatalyzed diazo-transfer reactions: diversity-oriented synthesis of diazo-compounds
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A practical and novel ionic liquid promoted organocatalytic selective diazo-transfer process for the synthesis of highly substituted diazo-compounds in high yields is reported. The ionic liquid can be reused without affecting the reaction rates or yields over five runs.
- Ramachary, Dhevalapally B.,Narayana, Vidadala V.,Ramakumar, Kinthada
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p. 2704 - 2709
(2008/09/19)
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- High-load, soluble oligomeric benzenesulfonyl azide: Application to facile diazo-transfer reactions
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The development of a high-load, soluble oligomeric sulfonyl azide using ROM polymerization is reported. The utility in diazo transfer reactions with active methylene compounds is demonstrated using an efficient protocol, with most reactions showing completion in 30 min. The sulfonamide byproduct, being insoluble in the reaction solvent, can be completely removed by simple filtration through a silica gel SPE cartridge.
- Harned, Andrew M.,Sherrill, W. Matthew,Flynn, Daniel L.,Hanson, Paul R.
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p. 12093 - 12099
(2007/10/03)
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- An improved and efficient method for diazo transfer reaction of active methylene compounds
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Diazo transfer reactions between active methylene compounds and the p-toluenesulfonyl azide can be efficiently mediated in the presence of cesium carbonate.
- Lee,Yuk
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p. 1511 - 1515
(2007/10/02)
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- Short and efficient access to β-ketoamides
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β-Ketoamides are obtained in good yields either through a photochemical rearrangement of diazodiketones or by aminolysis of β-ketoesters. photolysis / Wolff rearrangement / ketoketene / β-ketoesters / aminolysis /4-(dimethylamino)pyridine / β-ketoamides
- Cossy, Janine,Belotti, Damien,Bouzide, Abderahim,Thellend, Annie
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p. 723 - 729
(2007/10/02)
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- DIAZO GROUP TRANSFER AND/OR TRIAZOLE FORMATION IN THE REACTION OF TOLUENE-4-SULPHONYL OR 4-NITROPHENYL AZIDE WITH α-METHYLENE β-DICARBONYL COMPOUNDS IN HEXAMETHYLPHOSPHORIC TRIAMIDE
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In hexamethylphosphoric triamide, toluene-4-sulphonyl azide generally performs smooth diazo group transfer to β-dicarbonyl compounds, whereas 4-nitrophenyl azide can exhibit diazo transfer reaction with malonates and cyclic β-diones but leads to triazole formation with acyclic β-diones and β-keto esters.
- Benati, Luisa,Montevecchi, P. Carlo,Spagnolo, Piero
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p. 249 - 251
(2007/10/02)
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- Diazo transfer reaction in solid state
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A highly efficient methodology in solid state has been developed for the synthesis of α-diazocarbonyl/sulfonyl compounds from active methylene precursors using tosyl azide or 4-carboxybenzenesulfonyl azide and potassium carbonate, devoid of any aqueous work-up, save a column filtration over silica gel.
- Ghosh,Datta
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p. 191 - 200
(2007/10/02)
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- An improved synthesis of 2-diazo-1,3-diketones
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The sodium hydride/dibenzo-18-crown-6 ether system was found to be an effective base for the synthesis of 1,3-diketones by the Claisen condensation. The use of potassium fluoride (with or without crown ether) as the base in diazo-transfer reactions extends this reaction to the synthesis of hindered diazo diketones. In the case of isomeric 1,3-diketones, the stereoselectivity of the process considerably rises.
- Popic,Korneev,Nikolaev,Korobitsyna
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p. 195 - 198
(2007/10/02)
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- POTASSIUM FLUORIDE ON ALUMINA: AN EASY PREPARATION OF DIAZOCARBONYL COMPOUNDS
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A convenient synthesis of diazocarbonyl compounds from tosyl azide and carbonyl compounds with Al2O3-KF as solid base is reported.
- Alloum, Abdelkrim Ben,Villemin, Didier
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p. 2567 - 2572
(2007/10/02)
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- DIAZOTRANSFER REACTIONS WITH p-ACETAMIDOBENZENESULFONYL AZIDE
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The utility of p-acetamidobenzenesulfonyl azide in diazotransfer reactions is described.The practical, cost effective reagent offers advantages over existing alternatives.
- Baum, Jonathan S.,Shook, David A.,Daries, Huw M. L.,Smith, H. David
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p. 1709 - 1716
(2007/10/02)
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- PREPARATION OF α-DIAZO-β-KETOSULFONES BY DIAZO-TRANSFER REACTION WITH AN IN SITU GENERATED AZIDINIUM SALT. A SAFE AND EFFICIENT PROCEDURE FOR THE DIAZO-TRANSFER REACTION IN NEUTRAL MEDIUM.
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An efficinet and mild procedure is described for the preparation of α-diazo-β-ketosulfones using an azidinium salt generated in situ from relatively inexpensive and safe chemicals.The method is equally applicable to other CH2-acidic compounds.
- Monteiro, H. J.
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p. 983 - 992
(2007/10/02)
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- A Simple Procedure for Preparation of α-Diazocarbonyl Compounds
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The use of 1,8-diazabicycloundec-7-ene as a base in Regitz reaction leads to improved yields of α-diazocarbonyl compounds in much shorter time (15 min).
- Rao, Y. Koteswar,Nagarajan, M.
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p. 735 - 737
(2007/10/02)
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- Capture of Electron-Deficient Species with Aryl Halides. New Syntheses of Hypervalent Iodonium Ylides
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We have demonstrated the aryl iodide capture of β-diketocarbenes, generated from the diazo compound by using rhodium(II) acetate, under very mild conditions.This is a useful general preparative method for iodonium ylides under non-hydroxylic conditions.The termal, catalytic, and photochemical decompositions of various azides in the presence of aryl iodides were carried out.With highly reactive nitrenes, intramolecular rearrangement takes precedence over capture.In the case of p-tuloenesulfonyl azide, thermolysis in the presence of aryl iodides requires conditions under which the iminoiodane is itself decomposed.The capture of oxene by iodobenzene is discussed.The application of these capture processes is discussed as a synthetic route to hypervalent ylides as well as on the basis of mechanism.
- Moriarty, Robert M.,Bailey, B. R. III,Prakash, Om,Prakash, Indra
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p. 1375 - 1378
(2007/10/02)
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