- One-Pot Synthesis of Diazirines and 15N2-Diazirines from Ketones, Aldehydes and Derivatives: Development and Mechanistic Insight
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Broad scope one-pot diazirine synthesis strategies have been developed using two different oxidants depending on the nature of the starting material. In all cases, an inexpensive commercial solution of ammonia (NH3) in methanol (MeOH) was emplo
- Ibert, Quentin,Cauwel, Madeleine,Glachet, Thomas,Tite, Tony,Le Nahenec-Martel, Patricia,Lohier, Jean-Fran?ois,Renard, Pierre-Yves,Franck, Xavier,Reboul, Vincent,Sabot, Cyrille
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supporting information
p. 4390 - 4398
(2021/08/03)
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- Convenient fabrication of carbon doped WO3?x ultrathin nanosheets for photocatalytic aerobic oxidation of amines
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It is an important chemical transformation for oxidation of amines to imines, on account of very important versatile applications of imines in organic synthesis. Here, we develop a convenient way to synthesize carbon doped WO3?x ultrathin nanos
- Bao, Keyan,Zhang, Shaojie,Ni, Ping,Zhang, Zixiang,Zhang, Kailong,Wang, Liangbiao,Sun, Li Xia,Mao, Wutao,Zhou, Quanfa,Qian, Yitai
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p. 311 - 317
(2018/11/23)
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- Carbonylation Access to Phthalimides Using Self-Sufficient Directing Group and Nucleophile
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Herein we report a novel palladium-catalyzed oxidative carbonylation reaction for the synthesis of phthalimides with high atom- and step-economy. In our strategy, the imine and H2O, which are generated in situ from the condensation of aldehyde and amine, serve as self-sufficient directing group and nucleophile, respectively. This method provides rapid access to phthalimides starting from readily available materials in a one-pot manner. Various phthalimide derivatives are constructed efficiently, including medicinally and biologically active phthalimide-containing compounds.
- Ji, Fanghua,Li, Jianxiao,Li, Xianwei,Guo, Wei,Wu, Wanqing,Jiang, Huanfeng
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p. 104 - 112
(2018/02/19)
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- Structure-Reactivity Relationship in the Frustrated Lewis Pair (FLP)-Catalyzed Hydrogenation of Imines
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The autoinduced, frustrated Lewis pair (FLP)-catalyzed hydrogenation of 16-benzene-ring substituted N-benzylidene-tert-butylamines with B(2,6-F2C6H3)3 and molecular hydrogen was investigated by kinetic analysis. The pKa values for imines and for the corresponding amines were determined by quantum-mechanical methods and provided a direct proportional relationship. The correlation of the two rate constants k1 (simple catalytic cycle) and k2 (autoinduced catalytic cycle) with pKa difference between imine and amine pairs (ΔpKa) or Hammett's σ parameter served as useful parameters to establish a structure-reactivity relationship for the FLP-catalyzed hydrogenation of imines.
- Tussing, Sebastian,Kaupmees, Karl,Paradies, Jan
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supporting information
p. 7422 - 7426
(2016/05/24)
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- Hydrogen peroxide/dimethyl carbonate: A green system for epoxidation of: N -alkylimines and N -sulfonylimines. One-pot synthesis of N -alkyloxaziridines from N -alkylamines and (hetero)aromatic aldehydes
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A green method for epoxidation of imines using an environmentally benign oxidant system, H2O2/dimethyl carbonate, was developed. N-Alkyloxaziridines were prepared in high yields from N-alkylamines and (hetero)aromatic aldehydes in one-pot fashion, whereas N-sulfonyloxaziridines have been prepared by using the same oxidant system and 5 mol% of Zn(OAc)2·2H2O as catalyst.
- Kra?em, Jamil,Ghedira, Donia,Ollevier, Thierry
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supporting information
p. 4859 - 4864
(2016/10/12)
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- Synthesis of dihydrobenzisoxazoles by the [3 + 2] cycloaddition of arynes and oxaziridines
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Dihydrobenzisoxazoles are readily prepared in good yields by the [3 + 2] cycloaddition of oxaziridines and arynes. The reaction involves an unusual cleavage of the C-O bond of the oxaziridine and tolerates a variety of substituents on the oxaziridine and the o-(trimethylsilyl)aryl triflate to form aryl-, heteroaryl-, alkyl-, and naphthyl-substituted dihydrobenzisoxazoles. The resulting halogen-substituted dihydrobenzisoxazoles are readily elaborated to more complex products using palladium-catalyzed crossing-coupling processes.
- Kivrak, Arif,Larock, Richard C.
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supporting information; experimental part
p. 7381 - 7387
(2011/02/22)
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- Isoquinoline synthesis via rhodium-catalyzed oxidative cross-coupling/ cyclization of aryl aldimines and alkynes
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(Chemical Equation Presented) A general rhodium-catalyzed oxidative coupling reaction between internal alkynes and aryl aldimines is described. This process affords 3,4-disubstituted isoquinolines in good yield and high regioselectivity. Preliminary mechanistic studies suggest that the C-N bond formation arises from the reductive elimination of a rhodium(III) species.
- Guimond, Nicolas,Fagnou, Keith
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supporting information; experimental part
p. 12050 - 12051
(2010/01/29)
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- Oxidation of sulfides to sulfoxides with 3-aryl-2-tert-butyloxaziridines under high pressure
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3-Phenyl-2-tert-butyloxaziridine has been shown to behave as an oxidant under 800 MPa at 100°C to oxidize sulfides to sulfoxides, in spite of having been reported to be inactive as an oxidant and to undergo thermal rearrangement to W-tert-butyl-α-phenylnitrone at atmospheric pressure. It has been shown that under thermal and high-pressure conditions the ability of the oxaziridine to react changes dramatically. The mechanism for the high-pressure reaction is also discussed.
- Shimizu, Masao,Shibuya, Isao,Taguchi, Yoichi,Hamakawa, Satoshi,Suzuki, Kunio,Hayakawa, Takashi
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p. 3491 - 3492
(2007/10/03)
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- Synthesis, Proton NMR Stereochemical Study and Diels-Alder Reaction of (E)-7-Arylidene-2H,6H-naphthofuran-2,6-diones
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7-Arylidene-2H,6H-naphthofuran-2,6-diones 3 were prepared by a retro-Diels-Alder reaction of the corresponding dihydro 1,3-oxazines 2 or in a one pot synthesis from 6-hydroxy-2H-naphthofuran-2-one 1.Their E configuration was established fr
- Bouaziz, Zouhair,Fillion, Houda,Pinatel, Henri
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- A Facile Oxidation of Secondary Amines to Imines by Iodosobenzene or by a Terminal Oxidant and Manganese or Iron Porphyrins and Manganese Salen as the Catalysts
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The oxidation of secondary amines to imines by iodosobenzene or catalysed by either manganese(III) or iron(III) porphyrins, or by a manganese(III) salen complex with iodosobenzene as the oxygen donor has been investigated.Both aromatic and aliphatic amines can be oxidized smoothly to the corresponding imines with iodosobenzene as the oxidant and the elimination of hydrogen takes place towards the least substituted carbon.Manganese(III) and iron(III) porphyrins and manganese(III) salen are found to catalyse the oxidation of secondary amines to imines with iodosobenzene as the terminal oxidant.Those amines that are less reactive when iodosobenzene is the oxidant, can be converted to the imines in higher yields if a catalyst is added, compared with the uncatalysed reaction.By-products such as carbonyls and nitrones are found in some of these reactions.The manganese(III) salen complex is found to be the best catalyst, followed by manganese(III) porphyrin and iron(III) porphyrin.On the basis of Hammett plots, isotopic labelling studies and other experimental investigations the mechanisms for the uncatalysed and catalysed amine-to-imine oxidations are discussed.
- Larsen, Jan,Joergensen, Karl Anker
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p. 1213 - 1217
(2007/10/02)
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- Synthesis of organophosphorus compounds via silyl esters of phosphorous acids
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The addition of trimethylsilyloxy phosphorus (III)derivatives generated in situ to imines at room temperature provides a mild selective and high yielding route to α-aminoalkylphosphorate and α-aminoalkylphenylphosphinate esters. Isocyanates and carbodiimides react similarly to give phosphonoureas and phosphonoguarnidines respectively aldehydes and ketones are much less reactive and cyanides are inert.
- Afarinkia, Kamyar,Rees, Charles W.,Cadogan, John I. G.
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p. 7175 - 7196
(2007/10/02)
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- Reactions of N-Chloro-N-alkylbenzylamines with Amines in Acetonitrile. Origin of Steric Effect in Imine-Forming Elimination
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Reaction of N-chloro-N-alkylbenzylamines in which the alkyl group is Me, Et, i-Pr, sec-Bu, and t-Bu with MeNH2 and Et2NH in MeCN have been studied kinetically.The eliminations are quantitative and regiospecific, producing only N-benzylidenealkylamines.The relative rates of elimination for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents are 1/0.6/0.4/0.3/0.1 with MeNH2 and 1/0.5/0.3/0.2/0.03 with Et2NH, respectively.Comparison with published data reveals that Charton's value for the imine-forming elimination decreases with the variation of the base-solvent from MeONa-MeOH to MeNH2-MeCN but increases when the base is changed from MeNH2 to Et2NH.For a given base, Hammett ρ and kH/kD values decrease and the ΔH(excit.) and ΔS(excit.) values increase with bulkier alkyl substituents.From these results, the origin of the steric effect in imine-forming elimination is attributed to the repulsive interaction between the alkyl group and the base in the transition state.
- Cho, Bong Rae,Suh, Young Wook
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p. 2855 - 2858
(2007/10/02)
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- Reactions of N-Chlorobenzylalkylamines with Sodium Methoxide in Methanol. Steric Effects in Elimination Reactions
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Reactions of N-chlorobenzylalkylamines in which the alkyl group is Me, Et, i-Pr, t-Bu, and sec-Bu with MeONa-MeOH have been investigated kinetically.The eliminations are quantitative and regiospecific, producing only benzylidenealkylamines.The reactions are first order in base and first order in substrate, and an E2 mechanism is evident.The relative rates of elimination at 25 deg C are 1/0.5/0.3/0.2/0.01 for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents, respectively.The results are attributed to repulsive interaction between the alkyl group and the base in the transition state.Hammett ρ and kH/kD values decreased, but the ΔH(excit.) and ΔS(excit.) values increased with bulkier alkyl substituents.Changes in the transition-state parameters with the substrate steric effect are interpreted with variation in structure of the imine-forming transition states.
- Cho, Bong Rae,Maeng, Jun Ho,Yoon, Jong Chan,Kim, Tae Rin
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p. 4752 - 4756
(2007/10/02)
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- Oxygen Transfer fom Oxaziridines: A Chemical Model for Flavin-Dependent Monooxygenases
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The ability of several aryloxaziridines to transfer an oxygen atom to phenolates was examined. 2-(p-Nitrophenyl)-3-tert-butyloxaziridine (1) was found to oxidize potassium 2,6-dialkylphenolates to the corresponding p-benzoquinones.Product studies and an observed ESR signal suggest an electron-transfer mechanism for these oxidations. 18O-labeled oxaziridine 30 was prepared.Oxidations of phenolates with 30 rigorously establish the oxaziridine ring oxygen as the atom that is transferred to substrate.Kinetic studies with oxaziridine 1 and the isomeric nitrone 15 rule out the nitrone as an obligate intermediate in the oxygen-transfer reaction.In the oxidation of substrate, a single electron transfer from phenolate to oxaziridine is thought to generate a phenoxy/nitroxyl radical pair, which upon coupling and fragmentation achieves the oxygen transfer.These oxygen-transfer reactions serve as models for the proposed flavin-based oxaziridine 34 in enzyme-mediated monooxygenations.
- Wagner, William R.,Spero, Denice M.,Rastetter, William H.
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p. 1476 - 1480
(2007/10/02)
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