- Radical azidonation of benzylic positions with iodoninm azide
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Introduction of an azido substituent at the α position of benzyl ethers can be achieved by treating them with IN3 in refluxing acetonitrile. Some of the products obtained after 20 min - 5 h are given.
- Viuf, Christel,Bols, Mikael
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- Synthesis of new functionalized aryl and pyridyl aminomethylenebisphosphonic acids and their derivatives via silicon-assisted methodology
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The new convenient synthesis of functionalized aryl and pyridyl aminomethylenebisphosphonic acids and their derivatives has been developed via silicon-assisted methodology. New functionalized aminomethylenebisphosphonic acids containing pyridines moieties were obtained using unique reaction of tris(trimethylsilyl) phosphite with N-formyl aminopyridines and trimethylsilyl triflate as a catalyst under mild conditions. Intermediates – tetra(trimethylsilyl) aminomethylenebisphosphonates formed, were converted to the target acids by further treatment with methanol excess. In contrast the corresponding tetraethyl aminomethylenebisphosphonates were synthesized under heating (130 °C) of four component mixture (diethyl trimethylsilyl phosphite, triethyl orthoformate, aryl- or pyridylamine, and diethyl phosphite) in the presence of zinc chloride catalyst. The catalytic schemes of target substances formation are proposed and thoroughly discussed.
- Prishchenko, Andrey A.,Alekseyev, Roman S.,Livantsov, Mikhail V.,Novikova, Olga P.,Livantsova, Ludmila I.,Petrosyan, Valery S.
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- NAPHTHOFURAN DERIVATIVES, PREPARATION, AND METHODS OF USE THEREOF
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Provided herein are methods of preparation of I by reacting i with acid where R1 and R2 are each independently a leaving group. Intermediates to make i are also claimed.
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Paragraph 0171
(2018/06/22)
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- Ring-expanded N-heterocyclic carbenes as ligands in iron-catalysed cross-coupling reactions of arylmagnesium reagents and aryl chlorides
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The structure-activity relationship of expanded-ring N-heterocyclic carbenes (NHCs) in the iron-catalysed Kumada aryl-aryl coupling reaction was explored. This was achieved by comparing the catalytic performance of Fe-NHC catalysts generated in situ containing NHCs that differ in steric bulk. In particular, the influences of ring sizes (5-8) and N-aryl substituents were explored in terms of spectroscopic and structural features, which affect their %Vbur values. The three best performing ligands were found on a diagonal of a 5 × 4 structural matrix revealing an optimal steric bulk and significant influences of subtle steric variations on the catalytic activities.
- Teng, Qiaoqiao,Wu, Wenqin,Duong, Hung A.,Huynh, Han Vinh
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supporting information
p. 6044 - 6047
(2018/06/18)
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- Experimental and theoretical investigation of benzyl-N-pyrrolylketene, one- step procedure for preparing of new β-lactams by [2 +2] cycloaddition reaction
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3-Phenyl-2-(1-H-pyrrol-1-yl) propanoic acid has been used as a ketene source in synthesizing of monocyclic-2-azetidinones. Hindrance in ketene and imines successfully controlled the diastereoselectivity of the reaction. For example, in some cases only one isomer was achieved. By using Mukaiyama reagent, the leaving group in acid was activated and the by-products were separated by simple aqueous work-up. DFT calculation indicated that the benzyl-N-pyrrolylketene has nonconjugated structure and the pyrrolyl ring is perpendicular to the ketene plane in both the twisted and planar structures.
- Behzadi, Masoumeh,Saidi, Kazem,Islami, Mohammad Reza,Khabazzadeh, Hojatollah
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p. 111 - 117
(2016/02/09)
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- C–N cross-coupling on supported copper catalysts: The effect of the support, oxidation state, base and solvent
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A series of supported copper catalysts at two different loadings (1 and 2?wt%) have been prepared by deposition precipitation on various supports including TiO2, ZnO, Al2O3 and active carbon and submitted or not to reductive treatments to favor the increase in population of Cu(I). The samples have been characterized by textural measurements, electron microscopy and spectroscopic techniques including EPR and XPS, concluding the presence of dispersed copper oxides on the support with small particle size and contrasting prevalence of Cu(II) or Cu(I). The catalytic activity of all these catalysts for the C–N coupling of aniline and bromobenzene has been evaluated. A strong influence of the support, copper oxidation state, solvent, nature of the base was observed, the optimal conditions being the use of ZnO or TiO2 as supports and toluene/dioxane as solvent and EtOK as base. t-C5H11OK as base in either THF or toluene give rise to the formation of t-C5H11 phenyl ether in some extent. The catalyst undergoes deactivation during the reaction, but about 88% of the activity of the fresh sample could be regained by dioxane washings before reuse. XPS indicates that the most likely origin of catalyst deactivation is adsorption on the copper catalyst surface of KBr and inorganic salts formed as byproducts during the reaction.
- Tirsoaga, Alina,Cojocaru, Bogdan,Teodorescu, Cristian,Vasiliu, Florin,Grecu, Maria Nicoleta,Ghica, Daniela,Parvulescu, Vasile I.,Garcia, Hermenegildo
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p. 205 - 220
(2016/08/04)
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- Method for synthesizing N-(ethoxymethylene)aniline with styrene-styrene sulfonic acid copolymer microsphere as catalyst
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The invention relates to a method for synthesizing N-(ethoxymethylene)aniline with a styrene-styrene sulfonic acid copolymer microsphere as a catalyst. The method comprises the following steps: carrying out polymerization of styrene by using a soap-free emulsion polymerization process so as to obtain polystyrene (PS); then adding sodium styrene sulfonate (NaSS) and continuing soap-free emulsion polymerization so as to obtain a core-shell-structured sodium styrene-styrene sulfonate copolymer microsphere (PS-NaSS@PS); carrying out acidification so as to obtain styrene-styrene sulfonate copolymer microsphere (PS-HSS@PS); and synthesizing N-(ethoxymethylene)aniline with the synthesized styrene-styrene sulfonic acid copolymer microsphere (PS-HSS@PS) as the catalyst. The catalyst has good catalysis effect and can improve product purity; and recovery and recycling of the catalyst are realized, so pollutant emission is reduced, resources are saved and production cost is lowered.
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Paragraph 0015; 0016; 0017; 0018; 0019; 0020
(2017/04/27)
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- A facile protocol for the synthesis of mono-N-methyl anilines via formimidate intermediates
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A general procedure for the preparation of mono-N-methyl anilines has been developed with excellent yields. This protocol relies on a NaBH3(OAc) reduction of formimidate intermediates that are quantitatively generated by treatment of primary substituted anilines with triethyl orthoformate under the catalysis of MCM-41-SO3H mesoporous zeolite. The newly developed procedure was facile, efficient, and environmentally benign.
- Sun, Nan,Wang, Shuai,Mo, Weimin,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
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scheme or table
p. 7142 - 7148
(2010/09/14)
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