- Design and Remarkable Efficiency of the Robust Sandwich Cluster Composite Nanocatalysts ZIF-8@Au25@ZIF-67
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Heterogeneous catalysts with precise surface and interface structures are of great interest to decipher the structure-property relationships and maintain remarkable stability while achieving high activity. Here, we report the design and fabrication of the new sandwich composites ZIF-8@Au25@ZIF-67[tkn] and ZIF-8@Au25@ZIF-8[tkn] [tkn = thickness of shell] by coordination-assisted self-assembly with well-defined structures and interfaces. The composites ZIF-8@Au25@ZIF-67 efficiently catalyzed both 4-nitrophenol reduction and terminal alkyne carboxylation with CO2 under ambient conditions with remarkably improved activity and stability, compared to the simple components Au25/ZIF-8 and Au25@ZIF-8, highlighting the highly useful function of the ultrathin shell. In addition, the performances of these composite sandwich catalysts are conveniently regulated by the shell thickness. This concept and achievements should open a new avenue to the targeted design of well-defined nanocatalysts with enhanced activities and stabilities for challenging reactions.
- Yun, Yapei,Sheng, Hongting,Bao, Kang,Xu, Li,Zhang, Yu,Astruc, Didier,Zhu, Manzhou
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- 1,1′-Bis(di-tert-butylphosphino)ferrocene copper(i) complex catalyzed C-H activation and carboxylation of terminal alkynes
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Four copper(i) complexes, [CuBr(dtbpf)] (1), [CuI(dtbpf)] (2), [Cu4(μ2-I)2(μ3-I)2(μ-dtbpf)2] (3) and [Cu6(μ3-I)6(μ-dtbpf)2]·2CH3CN (4), were prepared using CuX (X = Br, I) and 1,1′-bis(di-tert-butylphosphino)ferrocene (dtbpf). These complexes have been characterized by elemental analyses, IR, 1H and 31P NMR, ESI-MS and electronic absorption spectroscopy. Molecular structures of the complexes 2 and 4 were determined crystallographically. Complex 2 is the first monomeric isolated Cu(i) complex of dtbpf with the largest P-Cu-P bite angle (120.070(19)°) to date. Complex 4 shows a centrosymmetrical dimeric unit with two [Cu3(μ3-I)3] motifs bridged by two bidentate dtbpf ligands in the κ1-manner. Each [Cu3(μ3-I)3] motif unites to form a pyramid with one copper atom at the apex and one of the triangular faces capped by an iodine atom. All the complexes were found to be efficient catalysts for the conversion of terminal alkynes into propiolic acids with CO2. Owing to the excellent catalytic activity, the reactions proceeded at atmospheric pressure and ambient temperature (25 °C). The catalytic products were obtained in moderate to good yields (80-96%) by using complex loading to 2 mol%. To the best of our knowledge, this is the first example of an active ferrocenyl diphosphine Cu(i) catalyst for the carboxylation of terminal alkynes with CO2.
- Trivedi, Manoj,Singh, Gurmeet,Kumar, Abhinav,Rath, Nigam P.
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- Rational encapsulation of atomically precise nanoclusters into metal-organic frameworks by electrostatic attraction for CO2 conversion
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Controlled encapsulation of atomically precise nanoclusters (APNCs) into metal-organic frameworks (MOFs) has been an efficient way to create new types of multifunctional crystalline porous materials. Such hybrids (APNCs@MOFs) provide ideal candidates for studying inherent structure-catalysis relationships owing to the well-defined compositions of both components. Moreover, modeling of APNCs@MOFs with precise structures would be more reliable. Herein, we have established an "Electrostatic Attraction Strategy" to synthesize APNCs@MOF catalysts and studied their performance as catalysts for the conversion of CO2. The synthetic strategy presented here has been proved to be general, as evidenced by the syntheses of various APNCs@MOF catalysts including all the combinations of [Au12Ag32(SR)30]4-, [Ag44(SR)30]4-, and [Ag12Cu28(SR)30]4- nanoclusters with ZIF-8, ZIF-67, and MHCF frameworks. In particular, the as-obtained Au12Ag32(SR)30@ZIF-8 composite shows excellent performance in capturing CO2 and converting phenylacetylene into phenylpropiolate under mild conditions (50 °C and ambient CO2 pressure) with a TON as high as 18164, far exceeding those of most known catalysts. What's more, the catalyst is very stable and reused 5 times without loss of catalytic activity. We anticipate that this general synthetic approach may open up a new frontier in the development of promising APNCs@MOF catalysts, which can be applied in a broad range of heterogeneous catalyses in the future.
- Sun, Lili,Yun, Yapei,Sheng, Hongting,Du, Yuanxin,Ding, Yimin,Wu, Pei,Li, Peng,Zhu, Manzhou
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- Copper(I)-modified covalent organic framework for CO2 insertion to terminal alkynes
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The carboxylation of terminal alkynes with CO2 is an attractive route for CO2 fixation and conversion, and various homogeneous Cu(I) catalysts have been explored for the reaction. However, it is still a challenge to develop efficient heterogeneous catalysts for the conversion under mild conditions. Considering that covalent organic frameworks (COFs) are emerging as versatile platforms for the design of functional materials, we developed a TpBpy-supported Cu(I) catalyst, where TpBpy is a stable imine-type porous COF furnished with rich N,N- and N,O-chelating sites for Cu(I) immobilization. The hybrid material can efficiently catalyze the conversion of CO2 and terminal alkynes to propiolic acids under relatively mild conditions (1 atm CO2, 60 ℃). The catalytic activity arises from the synergy between the organic framework of TpBpy and the Cu(I) sites. Not merely serving as a porous support to afford isolated and accessible Cu(I) sites, the organic framework itself has its own catalytic activity through the polar and basic N and O functional sites, which could activate the C–H bond and facilitate CO2 absorption. In addition, the framework also serves as a giant ligand to shift the reversible Cu(I)-catalyzed process in favor of carboxylation. The catalyst shows somewhat reduced activity after reused for three cycles owing to the oxidation of Cu(I) to Cu(II), but it can be easily regenerated by treating with KI.
- Bu, Ran,Zhang, Lin,Gao, Lu-Lu,Sun, Weng-Jie,Yang, Shuai-Liang,Gao, En-Qing
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- N-Heterocyclic carbene-nitrogen molybdenum catalysts for utilization of CO2
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Three new N-heterocyclic carbene-nitrogen molybdenum complex was synthesized, and its catalytic activity was evaluated in the cycloaddition of epoxides with CO2. The molybdenum complex combined with tetrabutyl ammonium iodide (TBAI) resulted in a catalytic system for efficient conversion of a wide range of terminal and internal epoxides under 80 °C and 5–7 bar pressure for CO2. The cooperative catalysis mechanism between molybdenum complex and TBAI was elucidated, in which molybdenum complex was used as Lewis acid, and TBAI was employed as nucleophilic reagent. In addition, the NHC-Mo catalytic system was also successfully applied for the direct carboxylation of terminal alkynes with CO2.
- Chen, Fei,Tao, Sheng,Liu, Ning,Dai, Bin
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- Schiff-base molecules and COFs as metal-free catalysts or silver supports for carboxylation of alkynes with CO2
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Carboxylation of terminal alkynes with CO2 to produce propiolic acids is an atom economical and high-value route for CO2 fixation and utilization, but the conversion under mild conditions needs transition metal catalysts. In this article, we demonstrated for the first time the transition-metal-free organocatalysts for the reaction. The efficient catalysts are Schiff bases derived from 1,3,5-triformylphloroglucinol (Tp), either homogeneous (discrete molecules) or heterogeneous (covalent organic frameworks, COFs). The key catalytic sites are phenoxo and imine groups, which activate CO2 through phenoxo-CO2 complexation and also activate the C(sp)-H bond through bifurcate C-H?Nimine and C-H?Ophenoxo hydrogen bonds. The 2,2′-bipyridyl sites in the COF also contribute to the catalytic performance. The COF catalyst is less active than the molecular one but has the advantages of heterogeneous catalysis. Higher performance was also demonstrated by combining silver nanoparticles (AgNPs) with the intrinsically catalytic COF. This work opens up the potential of developing transition-metal-free catalysts for the CO2 conversion reaction and demonstrates the new prospects of COFs as tailorable platforms for heterogeneous catalysis.
- Bu, Ran,Gao, En-Qing,Liu, Xiao-Yan,Mu, Peng-Fei,Zhang, Lin
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supporting information
p. 7620 - 7629
(2021/10/12)
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- Organocatalytic Strategy for the Fixation of CO2via Carboxylation of Terminal Alkynes
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An organocatalytic strategy for the direct carboxylation of terminal alkynes with CO2 has been developed. The combined use of a bifunctional organocatalyst and Cs2CO3 resulted in a robust catalytic system for the preparation of a range of propiolic acid derivatives in high yields with broad substrate scope using CO2 at atmospheric pressure under mild temperatures (60 °C). This work has demonstrated that this organocatalytic method offers a competitive alternative to metal catalysis for the carboxylation of terminal alkynes and CO2. In addition, this protocol was suitable for the three-component carboxylation of terminal alkynes, alkyl halides, and CO2.
- Shi, Jun-Bin,Bu, Qingqing,Liu, Bin-Yuan,Dai, Bin,Liu, Ning
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p. 1850 - 1860
(2021/01/14)
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- Oxidant- and additive-free simple synthesis of 1,1,2-triiodostyrenes by one-pot decaroboxylative iodination of propiolic acids
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A metal- and oxidant-free facile synthesis of a range of 1,1,2-triiodostryrene derivatives has been developed which utilizes a simple decarboxylative triiodination of propiolic acids using molecular iodine and sodium acetate in a one-pot manner. Electron-
- Ghosh, Subhankar,Ghosh, Rajat,Chattopadhyay, Shital K.
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- Silver Nanoparticles Architectured HMP as a Recyclable Catalyst for Tetramic Acid and Propiolic Acid Synthesis through CO2 Capture at Atmospheric Pressure
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The recent advancement on the tailored synthesis of hypercrosslinked microporous polymer (HMP-2) has assembled significant concentration by the virtue of its adjustable porosity, operative design and absolutely ordering structure. This perfectly structured Ag NPs supported carbocatalyst (Ag-HMP-2) has been synthesized by Friedel-Crafts alkylation between 4,4′-Bis(bromomethyl)-1,1′-biphenyl and carbazole over anhydrous iron(III)chloride catalysis followed by the appending of the silver nanoparticles (Ag NPs) onto the material. The silver nanoparticle was decorated over the HMP-2 to prepare the corresponding catalyst (Ag-HMP-2). The characterization of the newly produced material has been conducted by N2 adsorption/desorption studies, XPS, FE-SEM, transmission electron microscopy (TEM) and Powder X-ray diffraction (PXRD) methods. This microporous catalyst has spectacular activities for the production of tetramic acids from various types of propargylic amine derivatives at 60 °C under atmospheric carbon dioxide pressure. Parallel attempt on fixation of CO2 was executed over terminal alkynes to synthesize propiolic acids under 1 atm pressure. The catalyst (Ag-HMP-2) exhibited sufficient recycling ability for the generation of tetramic acids and propiolic acids up to five catalytic runs without reduction in its catalytic activity.
- Ghosh, Swarbhanu,Ghosh, Aniruddha,Riyajuddin, Sk,Sarkar, Somnath,Chowdhury, Arpita Hazra,Ghosh, Kaushik,Islam, Sk. Manirul
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p. 1055 - 1067
(2020/01/21)
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- Rhodium(III)-catalysed cascade [3 + 2] annulation of: N -aryloxyacetamides with 3-(hetero)arylpropiolic acids: Synthesis of benzofuran-2(3 H)-ones
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Herein, a cascade [3 + 2] annulation of N-aryloxyacetamides with 3-(hetero)arylpropiolic acids affording benzofuran-2(3H)-ones via rhodium(iii)-catalyzed redox-neutral C-H functionalization/isomerization/lactonization using an internal oxidative directing group O-NHAc was achieved. This catalytic system provides a regio- and stereoselective approach to synthesize (Z)-3-(amino(aryl)methylene)benzofuran-2(3H)-ones with exclusive Z configuration selectivity, acceptable yields and good functional group tolerance. Preliminary investigations on ultraviolet-visible and fluorescence behaviors reveal that the annulation products may be applied as a promising fluorescent probe for sensing metal cations, especially for cerium (Ce3+).
- Pan, Jin-Long,Liu, Tuan-Qing,Chen, Chao,Li, Quan-Zhe,Jiang, Wei,Ding, Tong-Mei,Yan, Zhi-Qiang,Zhu, Guo-Dong
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supporting information
p. 8589 - 8600
(2019/10/02)
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- Pd-Catalyzed decarboxylative alkynylation of alkynyl carboxylic acids with arylsulfonyl hydrazides via a desulfinative process
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In the presence of a Pd(ii)/P-ligand catalytic system, decarboxylative alkynylation of alkynyl carboxylic acids and arylsulfonyl hydrazides by desulfinative coupling could provide aryl alkynes in satisfactory yields by either judiciously selecting palladium catalysts or modulating phosphine ligands under mild conditions. The reported coupling reactions are very practical as they do not require the protection of inert gas or oxygen and are tolerant to many functional groups.
- Chang, Sheng,Liu, Ying,Yin, Shu Zhu,Dong, Lin Lin,Wang, Jian Feng
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supporting information
p. 5357 - 5362
(2019/04/04)
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- Visible Light-Catalyzed Decarboxylative Alkynylation of Arenediazonium Salts with Alkynyl Carboxylic Acids: Direct Access to Aryl Alkynes by Organic Photoredox Catalysis
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A convenient method mediated by photoredox catalysis is developed for the direct construction of aryl alkynes. Readily available aromatic diazonium salts have been utilized as the aryl radical source to couple alkynyl carboxylic acids to feature the decarboxylative arylation. A wide range of substrates are amenable to this protocol with broad functional group tolerance, and diversely-functionalized aryl alkynes could be synthesized under mild, neutral and transition metal-free reaction conditions using visible light irradiation. Alongside synthetic sustainability associated with the photocatalytic and transition metal-free operation, another key point of this method is that the organic dye catalyst acts as an excited-state reductant, thus establishing the quenching cycle for radical addition and decarboxylative elimination. (Figure presented.).
- Yang, Liangfeng,Li, Haifeng,Du, Yijun,Cheng, Kai,Qi, Chenze
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p. 5030 - 5041
(2019/11/03)
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- Fixation of CO2 as a carboxylic acid precursor by microcrystalline cellulose (MCC) supported Ag NPs: A more efficient, sustainable, biodegradable and eco-friendly catalyst
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Silver nanoparticles supported on microcrystalline cellulose (Ag NPs@MCC), an active catalyst, has been discovered for the direct carbonylation of terminal alkynes with CO2 into carboxylic acid under mild and sustainable reaction conditions. The stabilized Ag NPs show higher distribution with a uniform particle size. The catalyst was characterized by PXRD, SEM, TEM, HR-TEM, EDS, EDX, ICP-AES and XPS analysis. The Ag NPs@MCC material was found to be more efficient, shows excellent dispersion in various solvents and is biodegradable. The solvent effects on carbonylation of terminal alkynes were well studied both experimentally and computationally. Furthermore, the present catalyst can be recycled in up to five catalytic cycles without significant loss of its activity and is also applicable for the gram scale carbonylation of terminal alkynes.
- Shah, Dharmesh J.,Sharma, Anuj S.,Shah, Akshara P.,Sharma, Vinay S.,Athar, Mohd,Soni, Jigar Y.
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supporting information
p. 8669 - 8676
(2019/06/14)
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- Core-shell metal-organic frameworks and metal functionalization to access highest efficiency in catalytic carboxylation
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A core-shell metal-organic frameworks (MOF@MOF) based on the Zr-MOFs assembly from core-structure UiO-66 combined with shell-structure UiO-67-BPY were explored. The synthesized materials were characterized via XRD, FTIR, SEM, TEM, and surface area analysis, etc. indicating the presence of a core-shell structure of UiO-66@UiO-67-BPY. Furthermore, incorporation of the bipyridinic (BPY) group in the linker used to construct the shell layer (UiO-67-BPY) could coordinate with active metal species and thus create an advantage for site-selective metal incorporation in the core-shell structure. Silver (Ag) was selected for the selective metal incorporation and an excellent Ag-dispersion via coordination with the bipyridinic groups in the UiO-67-BPY layer of the core-shell material was obtained. The synthesized material (UiO-66@UiO-67-BPY-Ag) was successfully applied as a heterogeneous catalyst for the CO2 fixation via carboxylation of terminal alkynes. The catalytic material showed excellent yields using at a low Ag-loading under mild reaction condition (50 °C, 1 bar). Moreover, the catalyst can be recycled for at least 5 times maintaining a stable catalytic performance. Interestingly, the high catalytic activity of the synthesized material demonstrated clearly the beneficial advantage of the metalated core-shell structure over the reported routes to synthesize silver catalysts such as encapsulated Ag nanoparticles (AgNP@MOF) or Ag-bidentately coordinated on traditional MOFs applying the same reaction model.
- Gong, Yanyan,Yuan, Ye,Chen, Cheng,Zhang, Pan,Wang, Jichao,Zhuiykov, Serge,Chaemchuen, Somboon,Verpoort, Francis
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p. 106 - 115
(2019/02/14)
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- 3 - Aryl methylacetylene acid and 3 - aryl methylacetylene ester preparation method of compound (by machine translation)
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The invention relates to a 3 - aryl methylacetylene acid compound preparation method: formula (I) shown phenylacetylene compound with carbon dioxide under the action of alkali, in solvent dimethyl sulfoxide in 40 - 70 °C under reaction, as shown in formula (II) of the 3 - aryl methylacetylene acid compounds, more than normal pressure of the body reaction in water-free, oxygen-free inert atmosphere, the reaction route is as follows: Wherein R1 Selected from hydrogen, alkyl, alkoxy, phenyl, nitro or halogen. The invention further provides a 3 - aryl methylacetylene ester preparation method of compound: adopting the above-mentioned method of the formula (II) is shown in the 3 - aryl methylacetylene acid compound, then adding the halogenated hydrocarbon or tosylates, after the in-situ reaction of the formula (III) is shown in the 3 - aryl methylacetylene ester compound: Wherein R2 Is selected from alkyl, benzyl or allyl. The method of the invention does not need to transition metal or rare earth metal catalyst, normal pressure reaction, mild condition, pervasive good substrate. (by machine translation)
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Paragraph 0135; 0136; 0137
(2018/10/19)
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- A facile synthesis strategy to couple porous nanocubes of CeO2 with Ag nanoparticles: An excellent catalyst with enhanced reactivity for the 'click reaction' and carboxylation of terminal alkynes
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Oleic acid and oleylamine capped 3-D porous CeO2 nanocubes were synthesized by the hot injection method. The surface of the nanocube was modified with 2,4-dimethylphenol (DMP). The reducing and capping abilities of DMP to form Ag nanoparticles were explored to form noble metal nanoparticles over the porous CeO2 nanocubes support at room temperature. The surface modification and formation of Ag nanoparticles over the CeO2 support were thoroughly characterized with FTIR, UV-Vis spectroscopy, XRD, XPS, TEM, HRTEM, STEM, EDX and chemical mapping. This CeO2-Ag nanocomposite was found to have enhanced catalytic activities in the 'click reaction' as compared to unsupported Ag nanoparticles and porous CeO2 nanocubes; it was also found to have optimized catalytic activity in the carboxylation of terminal alkynes when Cs2CO3 was used as the base in DMF solvent at 80 °C. The reaction can give the desired product in yields as high as 98% under several experimental conditions via the green pathway. Recycling data showed that the catalyst could be reused five times without considerable loss of its activity and without any deterioration of physical conditions as observed by various characterization methods like TEM, EDX, XRD and XPS.
- Das, Subhasis,Mondal, Paramita,Ghosh, Swarbhanu,Satpati, Biswarup,Deka, Sasanka,Islam, Sk. Manirul,Bala, Tanushree
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p. 7314 - 7325
(2018/05/07)
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- Sequential protocol for C(sp)–H carboxylation with CO2: KOtBu-catalyzed C(sp)–H silylation and KOtBu-mediated carboxylation
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CO2 incorporation into C–H bonds is an important and interesting topic. Herein a sequential protocol for C(sp)–H carboxylation by employing a metal-free C–H activation/catalytic silylation reaction in conjunction with KOtBu-mediated carboxylation with CO2 was established, in which KOtBu catalyzes silylation of terminal alkynes to form alkynylsilanes at low temperature, and simultaneously mediates carboxylation of the alkynesilanes with atmospheric CO2. Importantly, the carboxylation further promotes the silylation, which makes the whole reaction proceed very rapidly. Moreover, this methodology is simple and scalable, which is characterized by short reaction time, wide substrate scope, excellent functional-group tolerance and mild reaction conditions, affording a range of corresponding propiolic acid products in excellent yields in most cases. In addition, it also allows for a convenient 13C-labeling through the use of 13CO2.
- Yu, Bo,Yang, Peng,Gao, Xiang,Yang, Zhenzhen,Zhao, Yanfei,Zhang, Hongye,Liu, Zhimin
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p. 449 - 456
(2018/02/06)
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- Method for preparing propiolic acid and derivatives thereof under mild condition
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The invention provides a novel method for preparing propiolic acid compounds through a domino reaction. The method comprises a step of subjecting terminal alkyne compounds, hydrosilane and CO2 to thedomino reaction under the catalysis action of Lewis base so as to obtain propiolic acid compounds. According to the invention, common Lewis base is used as a promoter, and corresponding propiolic acidcompounds containing different function groups can be efficiently produced through a reaction of the terminal alkyne compounds with hydrosilane and normal-pressure CO2 under a mild condition (a temperature of 40 DEG D). According to the method, CO2 is used as a raw material; the cheap Lewis base is used as the promoter; usage of precious metals is avoided; the domino reaction is employed; purification and separation of intermediates are not needed; and reaction conditions are mild. Thus, the method is an efficient cheap green synthetic method and has good industrial application value.
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Paragraph 0027; 0028; 0119; 0120
(2018/09/08)
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- Copper-Catalyzed, Stereoselective Bis-trifluoromethylthiolation of Propiolic Acid Derivatives with AgSCF3
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A copper-catalyzed chemo- and stereoselective oxidative bis-trifluoromethylthiolation of propiolic acid derivatives was achieved by using carboxylic acid as the activating group and formic acid as a cosolvent. The reaction of propiolic acid derivatives and AgSCF3 in the presence of (NH4)2S2O8 and catalytic Cu(OAc)2 in MeCN/HCO2H afforded bis-trifluoromethylthiolated acrylic acids in moderate to excellent yields with E selectivity. Further derivatization of the resultant products gave a series of polysubstituted SCF3-containing alkenes.
- Pan, Shen,Li, Huan,Huang, Yangen,Xu, Xiu-Hua,Qing, Feng-Ling
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supporting information
p. 3247 - 3250
(2017/06/23)
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- Tandem trifluoromethylthiolation/aryl migration of aryl alkynoates to trifluoromethylthiolated alkenes
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A trifluoromethylthiolation initiated aryl migration of aryl alkynoates was disclosed. This protocol employs AgSCF3 as the SCF3 source and MeCN as both the solvent and the hydrogen source. This provides a new access to trifluoromethylthiolated alkenes from readily available substrates and reagents.
- Li, Huan,Liu, Shuai,Huang, Yangen,Xu, Xiu-Hua,Qing, Feng-Ling
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supporting information
p. 10136 - 10139
(2017/09/23)
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- Development of new scaffolds as reversible tissue transglutaminase inhibitors, with improved potency or resistance to glutathione addition
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Previous studies within our group have yielded a class of cinnamoyl-based competitive reversible inhibitors for tissue transglutaminase (TG2), with Ki values as low as 1.0 μM (compound CP4d). However, due to the electrophilic nature of their al
- Apperley, Kim Y. P.,Roy, Isabelle,Saucier, Vincent,Brunet-Filion, Nicholas,Piscopo, Sara-Pier,Pardin, Christophe,De Francesco, élise,Hao, Catherine,Keillor, Jeffrey W.
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p. 338 - 345
(2017/03/08)
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- A Schiff base-modified silver catalyst for efficient fixation of CO2 as carboxylic acid at ambient pressure
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The fixation of CO2 as a carboxylic acid is a significant reaction for C-C bond formation in organic synthesis. So far, besides C-H carboxylations using stoichiometric amounts of metals or organometallic reagents, great efforts have been devoted to develop new heterogeneous catalyst, while the catalytic performance of supported metal catalysts is not satisfactory. Herein, a Schiff base-modified silver catalyst was developed for the direct carboxylation of terminal alkynes with CO2, enabling an efficient and green synthesis of valuable alkynyl carboxylic acids. The reaction can smoothly proceed under atmospheric pressure and low temperature (60 °C) conditions. Moreover, a silver-based catalyst, which was prepared by an in situ reduction route, can be easily prepared, recovered, and reused five times without significant loss of activity due to the stability promoted by the Schiff-base on the support surface. In addition, the markedly negative influence of H2O and solvent effect on this reaction system has also been discussed.
- Wu, Zhilian,Sun, Lei,Liu, Qinggang,Yang, Xiaofeng,Ye, Xue,Hu, Yancheng,Huang, Yanqiang
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supporting information
p. 2080 - 2085
(2017/07/24)
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- Cis -1,2-Bis(diphenylphosphino)ethylene copper(i) catalyzed C-H activation and carboxylation of terminal alkynes
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The reaction of cis-1,2-bis(diphenylphosphino)ethylene (dppet) with CuX (X = CN, SCN) in 1:1 M molar ratio in DCM-MeOH (50:50 V/V) under refluxing conditions gave two dimeric Cu(i) complexes, viz. [Cu2(μ-CN)2(κ2-P,P-dppet)2] (1) and [Cu2(μ2-SCN)2(κ2-P,P-dppet)2] (2). These complexes have been characterized by elemental analyses, IR, 1H and 31P NMR, and electronic absorption spectroscopies, and ESI-MS. The molecular structure of 2 was confirmed by single crystal X-ray diffraction, which indicated that 2 exists as a centrosymmetric dimer in which the two copper centers are bonded to two dppet ligands and two bridging thiocyanate groups in a μ2-manner. The electrochemical properties of 1 and 2 were studied by cyclic voltammetry. Both the complexes exhibited strong luminescence properties in the solution state at ambient temperature. Both the complexes were found to be efficient catalysts for the conversion of terminal alkynes into propiolic acids with CO2. Owing to their excellent catalytic activity, the reactions proceed at atmospheric pressure and ambient temperature (25 °C). The catalytic products were obtained in excellent yields (90-97%) by using the complex loading of 1 mol%.
- Trivedi, Manoj,Smreker, Jacob R.,Singh, Gurmeet,Kumar, Abhinav,Rath, Nigam P.
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p. 14145 - 14151
(2017/11/28)
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- Carboxylation of Terminal Alkynes with Carbon Dioxide Catalyzed by an In Situ Ag2O/N-Heterocyclic Carbene Precursor System
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A carboxylation of terminal alkynes with carbon dioxide (CO2) at ambient conditions was developed in situ using a series of N-heterocyclic carbene (NHC) precursors and Ag2O. The unique structure of NHCs largely increases the solubility of active Ag species and meanwhile activates CO2 by forming the NHC–CO2 adduct. This novel catalytic system demonstrated quite low Ag loading, very high activities, wide substrate generality and excellent tolerance for a variety of functionalities. In addition, avoiding cumbersome synthesis procedures, processing, and reserving of the photosensitive Ag complex, this system could be stored and operated as straightforward as the inorganic Ag salt catalysts.
- Yuan, Ye,Chen, Cheng,Zeng, Cheng,Mousavi, Bibimaryam,Chaemchuen, Somboon,Verpoort, Francis
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p. 882 - 887
(2017/03/13)
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- CsF-promoted carboxylation of aryl(hetaryl) terminal alkynes with atmospheric CO2 at room temperature
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A CsF-promoted carboxylation of aryl(hetaryl) terminal alkynes with atmospheric CO2 in the presence of trimethylsilylacetylene was developed to give functionalized propiolic acid products at room temperature. A wide range of propiolic acids bearing functional groups was successfully obtained in good to excellent yields. Mechanistic studies demonstrate that in the carboxylation process the alkynylsilane intermediate was first in situ generated, which was then trapped by CO2, giving rise to the corresponding functionalized propiolic acids after acidification. The advantages of this approach include avoiding use of transition-metal catalysts, wide substrate scope together with excellent functional group tolerance, ambient conditions and a facile work-up procedure.
- Yu,Yang,Gao,Yang,Zhao,Zhang,Liu
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supporting information
p. 9250 - 9255
(2017/08/29)
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- Iodine-catalyzed Sulfonylation of Arylacetylenic Acids and Arylacetylenes with Sodium Sulfinates: Synthesis of Arylacetylenic Sulfones
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A highly efficient and generally applicable iodine-catalyzed reaction of arylacetylenic acids and arylacetylenes with sodium sulfinates for the synthesis of arylacetylenic sulfones was developed. The methodology has the advantages of a metal-free strategy, easy to handle reagents, functional group tolerance, a wide range of arylacetylenic acids and arylacetylenes, and easy access to arylacetylenic sulfones. (Chemical Equation Presented).
- Meesin, Jatuporn,Katrun, Praewpan,Pareseecharoen, Chayaporn,Pohmakotr, Manat,Reutrakul, Vichai,Soorukram, Darunee,Kuhakarn, Chutima
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p. 2744 - 2752
(2016/04/26)
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- A bridged bis-amide-based rare earth amine compound and its preparation method and application
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The invention discloses bridged bisamido rare-earth amide compounds, and a preparation method and catalytic application thereof. The general formula of the rare-earth compounds is {LLn[N(SiMe3)2].THF}2, and the chemical structural formula is disclosed in the specification. In the general formula, L represents a bridged bisamido ligand, and the ligand LH2 is N,N'-(cyclohexane-1,2-diyl)bis(4-tert-butylbenzamide); and Ln is a rare-earth metal selected from lanthanum, neodymium, samarium, yttrium or ytterbium. The bridged bisamido rare-earth amide compounds have the advantages of simple synthesis process, definite structure and high yield. The invention also discloses a preparation method of the compounds and an application method of the compounds as a catalyst for catalyzing carboxylation reaction between alkynyl terminal group and carbon dioxide. The application method has the advantages of mild conditions, high activity, favorable selectivity and wide substrate application range.
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Paragraph 0123; 0124
(2017/04/21)
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- Method for preparing propiolic acid compounds
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The invention discloses a method for preparing propiolic acid compounds. An ionic type iron (III) complex containing monoimide functionalized imidazolium cations is taken as the single-component catalyst, carbon dioxide is taken as the carboxylation reagent, and various propiolic acid compounds are prepared through carboxylation reaction of terminal alkyne under normal pressure. The terminal alkyne substrate relates to phenylacetylene, substituted phenylacetylene, heterocyclic aryne, aromatic diyne or aliphatic series terminal alkyne. The method for preparing the propiolic acid compounds through carboxylation reaction of terminal alkyne and carbon dioxide under the catalysis of the iron-based catalyst is provided for the first time. Compared with the prior art, the method has the advantages that the catalyst is more environmentally friendly, synthesis is easier, reaction conditions are mild, and catalytic activity and functional group tolerance are unchanged or improved.
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Paragraph 0052; 0053
(2016/10/10)
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- Carboxylation of terminal alkynes with CO2 using novel silver N-heterocyclic carbene complexes
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Four novel N-heterocyclic carbene (NHC) silver complexes, I-IV, have been synthesized and characterized. The single X-ray crystal diffraction data indicate a dinuclear solid-state structure for I and III and a mononuclear structure for II and IV. These complexes have been successfully used as efficient catalysts for the C-H activating carboxylation of terminal alkynes with CO2. A wide range of substrates with various functional groups afforded the corresponding aryl or alkyl substituted propiolic acids in good yields under mild conditions. Moreover, the role of bases and the reaction mechanism is thoroughly discussed.
- Li, Shanshan,Sun, Jing,Zhang, Zhizhi,Xie, Ruixia,Fang, Xiangchen,Zhou, Mingdong
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p. 10577 - 10584
(2016/07/07)
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- Carboxylation of terminal alkynes with CO2 catalyzed by bis(amidate) rare-earth metal amides
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Three novel bis(amidate) rare-earth metal amides {LRE[N(SiMe3)2]·THF}2 (H2L = N,N′-(cyclohexane-1,2-diyl)bis(4-tert-butylbenzamide); RE = La(1), Nd(2), Y(3)), which were prepared by the treatment of the bridged amide proligand H2L with RE[N(SiMe3)2]3 in tetrahydrofuran, have been characterized by single-crystal X-ray diffraction, elemental analyses, and NMR for complexes 1 and 3. All the complexes were found, for the first time, to be efficient catalysts for the direct carboxylation of terminal alkynes with CO2 at ambient pressure. And the Nd-based catalyst 2 showed the highest reactivity. Various propiolic acids with a good functional group tolerance were successfully synthesized in high-to-excellent yields under mild conditions. This journal is
- Cheng, Hao,Zhao, Bei,Yao, Yingming,Lu, Chengrong
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p. 1675 - 1682
(2015/03/18)
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- Design, synthesis and evaluation of novel diaryl urea derivatives as potential antitumor agents
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A novel series of diaryl ureas containing different linker groups were designed and synthesized. Their in vitro antitumor activity against MX-1, A375, HepG2, Ketr3 and HT-29 was evaluated using the standard MTT assay. Compounds having a rigid linker group such as vinyl, ethynyl and phenyl showed significant inhibitory activity against a variety of cancer cell lines. Specifically, compound 23 with a phenyl linker group demonstrated broad-spectrum antitumor activity with IC50 values of 5.17-6.46 μM against five tested tumor cell lines. Compound 23 is more potent than reference drug sorafenib (8.27-15.2 μM), representing a promising lead for further optimization.
- Lu, Chenshu,Tang, Ke,Li, Yan,Li, Peng,Lin, Ziyun,Yin, Dali,Chen, Xiaoguang,Huang, Haihong
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p. 351 - 360
(2014/04/17)
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- Carboxylation of alkynylsilanes with carbon dioxide mediated by cesium fluoride in DMSO
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The facile syntheses of a variety functionalized propiolic acids were achieved by carboxylation of alkynylsilanes with carbon dioxide mediated by cesium fluoride under ambient conditions. This journal is The Royal Society of Chemistry 2013.
- Yonemoto-Kobayashi, Misato,Inamoto, Kiyofumi,Tanaka, Yoshiyuki,Kondo, Yoshinori
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supporting information
p. 3773 - 3775
(2014/03/21)
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- CHEMICAL COMPOUNDS
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The invention is directed to substituted heteroaryl derivatives. Specifically, the invention is directed to compounds according to Formula Q: wherein D, L, M, W, X, Y, and Z are defined herein. The compounds of the invention are inhibitors of DNA methyltransferase (DNMT) activity - including DNMT1, DNMT3a, or DNMT3b- and are useful in the treatment of cancer and hyperproliferative diseases. Accordingly, the invention is further directed to pharmaceutical compositions comprising a compound of the invention. The invention is still further directed to methods of inhibiting DNMT activity and treatment of disorders associated therewith using a compound of the invention or a pharmaceutical composition comprising a compound of the invention
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- Palladium-catalyzed sonogashira reaction for the synthesis of arylalkynecarboxylic acids from aryl bromides at low temperature
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A variety of aryl bromides were coupled with propiolic acid in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and catalyst Pd(PPh 3)4 to afford the corresponding arylalkynecarboxylic acids in good yields at low temperature. This method showed good tolerance toward functional groups such as alkoxy, ketone, ester, aldehyde, cyano, nitro, and hydroxy. Under these conditions, propiolic acid showed higher reactivity than any other compound containing terminal alkyne groups. According to the mechanistic studies, the key reaction step for the high reactivity of propiolic acid might be ligand exchange between the acetylide and bromide at palladium, and/or reductive elimination, but not the oxidative addition step. A variety of aryl bromides were coupled with propiolic acid in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and catalyst Pd(PPh3) 4 to afford the corresponding arylpropiolic acids in good yields at low temperature.
- Park, Kyungho,You, Jung-Min,Jeon, Seungwon,Lee, Sunwoo
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p. 1973 - 1978
(2013/05/09)
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- Copper catalysed domino decarboxylative cross coupling-cyclisation reactions: Synthesis of 2-arylindoles
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The efficient synthesis of 2-arylindoles and 6H-isoindolo[2,1-a]indol-6-one through copper catalysed domino sp-sp2 decarboxylative cross-coupling and subsequent cyclisation reactions of arylpropiolic acids with 2-iodotrifluoroacetanilide has been described. This methodology also demonstrates that indolo[1,2-c]quinazolin-6(5H)-one can be obtained with the elimination of trifluoromethyl anion.
- Ponpandian, Thanasekaran,Muthusubramanian, Shanmugam
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supporting information; experimental part
p. 4248 - 4252
(2012/08/28)
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- Carboxylation of terminal alkynes with carbon dioxide catalyzed by Poly(N-Heterocyclic Carbene)-supported silver nanoparticles
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An N-heterocyclic carbene (NHC) polymer supported silver nanoparticle catalyst system was developed. The novel nano-composite catalyst demonstrated very high activity and excellent stability and reusability in the carboxylation of terminal alkynes with carbon dioxide at ambient conditions. The unique N-heterocyclic carbene polymer and silver nanoparticle composite structure provided a synergistic effect on activation of terminal alkynes and carbon dioxide that contributed to the high catalytic activity. The poly-NHC-silver catalyst exhibited excellent substrate generality and tolerance to various functionalities. In addition, the catalyst is stable to air and moisture and can be easily recovered and reused. Copyright
- Yu, Dingyi,Tan, Mei Xuan,Zhang, Yugen
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supporting information; experimental part
p. 969 - 974
(2012/05/31)
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- The direct carboxylation of terminal alkynes with carbon dioxide
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A simple and straight-forward method has been developed for direct carboxylation of terminal alkynes using CO2 as the C1 carbon feedstock. The direct C-H bond functionalization is achieved with Cs 2CO3 as the base and in the absence of transition metal catalyst. Various propiolic acids were synthesized in good to excellent yields with a wide substrate scope and a good functional groups tolerance. This is a more atom- and step-economic protocol with great potential in practical application.
- Dingyi, Yu,Yugen, Zhang
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experimental part
p. 1275 - 1279
(2011/06/26)
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- Ligand-free Ag(I)-catalyzed carboxylation of terminal alkynes with CO 2
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Chemical equations presented. A convenient approach to selectively prepare a wide range of functionalized propiolic acids was developed by AgI-catalyzed carboxylation of terminal alkynes using carbon dioxide as carboxylative agent under ligand-free conditions.
- Zhang, Xiao,Zhang, Wen-Zhen,Ren, Xiang,Zhang, Lin-Lin,Lu, Xiao-Bing
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supporting information; experimental part
p. 2402 - 2405
(2011/06/25)
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- CARBOXYLATION OF TERMINAL ALKYNES
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The present invention describes a process for converting a terminal alkyne into an alkynoic acid. In this process the alkyne is exposed to carbon dioxide in the presence of a copper (I) species, a base and a complexing agent capable of complexing copper (I).
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Page/Page column 20; 26
(2011/07/07)
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- Palladium (II/IV) catalyzed cyclopropanation reactions: scope and mechanism
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This report describes detailed studies of the scope and mechanism of a new Pd-catalyzed oxidation reaction for the stereospecific conversion of enynes into cyclopropyl ketones. Unlike related PdII/0, Au, and Pt-catalyzed cyclopropane-forming reactions, these transformations proceed with net inversion of geometry with respect to the starting alkene. This result, along with other mechanistic data, is consistent with a PdII/IV mechanism in which the key cyclopropane-forming step involves nucleophilic attack of a tethered olefin onto a PdIV-C bond.
- Lyons, Thomas W.,Sanford, Melanie S.
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experimental part
p. 3211 - 3221
(2009/09/05)
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- Protonation of 3-arylpropynoic acid derivatives in superacids
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According to the 1H and 13C NMR data, 3-arylpropynoic acids and their esters XC6Hn-C≡C-CO2R (R = H, Me, Et) having electron-withdrawing substituents in the benzene ring (X = NO2, CN, COMe,
- Walspurger,Vasil'ev,Sommer,Pale,Savechenkov,Rudenko
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p. 1485 - 1492
(2007/10/03)
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- (Ethoxycarbonyliodomethyl)triphenylphosphonium Iodide: A Convenient Reagent for the Direct Synthesis of β-Substituted Propiolic Acids via the Corresponding Esters
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Reaction between (ethoxycarbonyliodomethyl)triphenylphosphonium iodide, potassium carbonate, and various aromatic or aliphatic aldehydes in a liquid solid two phases system gives β-substituted propiolic esters.The corresponding acids are obtained in good yield by hydrolysis.
- Chenault, Jaques,Dupin, Jean-Francois E.
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p. 498 - 499
(2007/10/02)
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- Substitution and Elimination Reactions in Chloroolefins: Effect of Solvents
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The rates of elimination of some (Z)-methyl-β-chloro-p-substituted cinnamates with sodium methoxide in methanol containing 0 to 40 mol percent of dimethyl sulphoxide (DMSO) have been determined.Significant rate increase occurs even at low DMSO concentration.The increase in rate is attributed to a large reduction in both the enthalpie and entropie of activation as the medium is made less protic by the addition of DMSO.In contrast to the effect on rate, the Hammett reaction constant (ρ) is not changed appreciably by adding DMSO.
- Youssef, Abdel-Hamid A.,Sharaf, Saber M.,El-Sadany, Samir K.,Hamed, Ezzat A.
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p. 359 - 361
(2007/10/02)
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