- Nickel-Catalyzed Regiodivergent Reductive Hydroarylation of Styrenes
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We report a ligand-controlled nickel-catalyzed reductive hydroarylation of styrenes with predictable and controllable regioselectivity. With a diamine ligand, the reaction produces selective linear hydroarylation products. Alternatively, with a chiral PyrOx ligand, branch-selective enantioenriched 1,1-diarylalkane products are obtained. Preliminary mechanistic results are consistent with a reductive Heck process.
- Xue, Yuhang,Chen, Jian,Song, Peihong,He, Yuli,Zhu, Shaolin
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p. 1647 - 1651
(2021/07/02)
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- Photoredox-Catalyzed α-Aminomethyl Carboxylation of Styrenes with Sodium Glycinates: Synthesis of γ-Amino Acids and γ-Lactams
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A visible-light photoredox-catalyzed reductive α-aminomethyl carboxylation of styrenes with sodium glycinates and CO2 has been developed to synthesize a series of α,α-disubstituted γ-amino acids and γ-lactams with high efficiency and regioselectivity. Notably, CO2 released from the decarboxylation step can be reused for the subsequent carboxylation. Distinct from the previous reactions with the same type of substrates leading to simple decarboxylation and olefin hydroalkylation, this process involves additional CO2 sequestration, thus leading to olefin α-aminomethyl carboxylation. These findings not only provide new access to α,α-disubstituted γ-amino acids and γ-lactams but also serve as a proof of concept for CO2 reutilization in decarboxylation reactions.
- Zhou, Cong,Li, Miao,Sun, Jianwei,Cheng, Jiang,Sun, Song
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supporting information
p. 2895 - 2899
(2021/05/05)
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- The Concept of Photozymes: Short Peptides with Photoredox Catalytic Activity for Nucleophilic Additions to α-Phenyl Styrenes
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Conventional photoredox catalytic additions of alcohols to olefins require additives, like thiophenol, to promote back electron transfer. The concept of “photozymes” assumes that forward and backward electron transfer steps in a photoredox catalytic cycle
- Sack, Daniel,Wagenknecht, Hans-Achim
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p. 6400 - 6407
(2021/11/18)
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- TMSOTf-mediated synthesis of skipped dienes through the addition of olefins to imines and semicyclicN,O-acetals
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A novel approach to skipped dienes has been developed through the TMSOTf-mediated one-pot addition-substitution of olefins2a,2fand2gwith imines1a-1g, and a series of aryl substituted skipped dienes3aa-3gfwere accordingly obtained in 62%-94% yields. Moreov
- Feng, Yi-Man,Nie, Xiao-Di,Sun, Jian-Ting,Wei, Bang-Guo,Xu, Wen-Ke
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p. 7883 - 7893
(2021/09/28)
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- Deaminative carbonylative coupling of alkylamines with styrenes under transition-metal-free conditions
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A transition-metal-free deaminative carbonylation of alkylamines with styrenes has been developed. The reaction shows good functional group compatibility and various α,β-unsaturated ketones were obtained in moderate to good yields. The alkyl radical generated from Katritzky salts via base-promoted C-N bond cleavage is one of the key intermediates in this reaction. This journal is
- Zhao, Fengqian,Li, Chong-Liang,Wu, Xiao-Feng
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supporting information
p. 9182 - 9185
(2020/08/26)
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- Regiodivergent DH or HD Addition to Alkenes: Deuterohydrogenation versus Hydrodeuterogenation
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The regioselective and regiodivergent addition of H-D to a variety of 1,1-diarylalkenes was realized utilizing selectively deuterated dihydroaromatic compounds, which were generated by cobalt catalysis. The reaction was initiated by catalytic amounts of B
- Hilt, Gerhard,Li, Luomo
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supporting information
(2020/03/03)
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- Enantioselective Radical-Polar Crossover Reactions of Indanonecarboxamides with Alkenes
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Highly efficient asymmetric intermolecular radical-polar crossover reactions were realized by combining a chiral N,N′-dioxide/NiII complex catalyst with Ag2O under mild reaction conditions. Various terminal alkenes and indanonecarboxamides/esters underwent radical addition/cyclization reactions to afford spiro-iminolactones and spirolactones with good to excellent yields (up to 99 %) and enantioselectivities (up to 97 % ee). Furthermore, a range of different radical-mediated oxidation/elimination or epoxide ring-opening products were obtained under mild reaction conditions. The Lewis acid catalysts exhibited excellent performance and precluded the strong background reaction.
- Cao, Weidi,Feng, Xiaoming,Liu, Xiaohua,Wu, Wangbin,Xu, Xi,Yu, Han,Zhang, Xiying
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supporting information
p. 4846 - 4850
(2020/02/11)
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- New poly-imidazolium-triazole particles by CuAAC cross-linking of calix[4]arene bis-azide/alkyne amphiphiles - a prospective support for Pd in the Mizoroki-Heck reaction
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A new imidazolium amphiphilic calix[4]arene with terminal acetylene fragments in the polar region was synthesized according to a two step scheme including regioselective chloromethylation of distal di-O-butyl calix[4]arene and subsequent interaction with 1-(hex-5-yn-1-yl)-1H-imidazole. The aggregation properties (CAC, the size and zeta potential of aggregates) of alkynyl calix[4]arene as well as of previously synthesized azidopropyl calix[4]arene and their 1?:?1 mixture were disclosed. Macrocycles with azide and alkyne fragments in the polar region were covalently cross-linked under CuAAC conditions in water. Successful cross-linking of molecules has been proven by IR spectroscopy and MALDI-TOF spectrometry. The obtained polymeric particles were studied both in solution and the solid state and the presence of submicron (~200 nm) and micron (~1-5 μm) particles with the prevalence of the latter was found. The average molecular weight of the polymer according to the static light scattering data was found to be 639 ± 44 kDa. The obtained polymeric imidazolium-triazole particles were tested as a support for Pd(OAc)2in the Mizoroki-Heck reaction carried out in both organic and water media. In both solvents (especially in water) the addition of imidazolium-triazole particles to Pd(OAc)2increased the conversion of 4-iodanisole. It was found that the ratio between the products (1,1 and 1,2-substituted ethylenes) changes drastically on going from DMF to water from 1?:?5 to 1?:?40 when using supported Pd(OAc)2
- Burilov, Vladimir,Garipova, Ramilya,Mironova, Diana,Sultanova, Elza,Bogdanov, Ilshat,Ocherednyuk, Evgeny,Evtugyn, Vladimir,Osin, Yuri,Rizvanov, Ildar,Solovieva, Svetlana,Antipin, Igor
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p. 584 - 591
(2021/02/09)
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- The role of phosphine ligands in the catalytic systems of the Heck reaction with aromatic carboxylic anhydrides
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The results of a comparative study of phosphine-containing and phosphine-free catalytic systems of the Heck reaction using aromatic carboxylic anhydrides as arylating agents are presented. It was demonstrated that the patterns of diff erential selectivity of the reaction under competition of two aromatic anhydrides or two alkenes are independent of the presence of a tertiary phosphine additive in the system. It was established that palladium complexes with no phosphine ligands in their coordination sphere are catalytically active at the step of activation of aromatic carboxylic anhydride and alkene. The patterns of diff erential selectivity for regioisomers of arylated products provide the evidence of the participation of phosphine-containing anionic palladium complexes in the regioselectivity-determining step of the catalytic cycle. The data obtained are in agreement with the phosphine involvement in the catalyst transformations proceeding outside the main catalytic cycle.
- Lagoda,Larina,Yarosh,Kurokhtina,Schmidt
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p. 817 - 824
(2019/06/03)
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- Toward a Greener Barluenga-Valdés Cross-Coupling: Microwave-Promoted C-C Bond Formation with a Pd/PEG/H2O Recyclable Catalytic System
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A green Barluenga-Valdés cross-coupling reaction for the synthesis of 1,1-diarylethylenes using palladium catalysis has been developed. The new catalytic system based on Pd/Xphos-SO3Na or Pd/MeDavephos-CF3SO3 in PEG/H2O under microwave irradiation was found to be the best conditions for this transformation. The recyclability of the palladium catalyst system was also studied, and it was found to be active over nine runs without significant loss in its activity.
- Lamaa, Diana,Messe, Estelle,Gandon, Vincent,Alami, Mouad,Hamze, Abdallah
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supporting information
p. 8708 - 8712
(2019/11/03)
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- Halogenation of 1,1-diarylethylenes by N-halosuccinimides
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An efficient method for the preparation of 2,2-diarylvinyl halides from the corresponding 1,1-diarylethylenes has been developed. N-Halosuccinimides (N-bromosuccinimide or N-chlorosuccinimide) were used as the halogenation reagents. The practicability of this method is highlighted by its simple operation, broad substrate scope and capability for large-scale reaction.
- Zhang, Ge,Bai, Rui-Xue,Li, Chu-Han,Feng, Chen-Guo,Lin, Guo-Qiang
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supporting information
p. 1658 - 1662
(2018/12/11)
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- Photocatalytic, Phosphoranyl Radical-Mediated N-O Cleavage of Strained Cycloketone Oximes
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A photoinduced, phosphoranyl radical-mediated protocol for the direct N-O cleavage of strained cycloketone oximes via a polar/SET crossover process was developed for the first time. This visible-light-driven direct N-O activation mode for oxime offers beneficial features such as streamlined synthetic process and versatile photochemical reactivities. Consequently, the alkenes and α-trifluoromethyl alkenes with varied electronic and structural features acted as competent radical receptors in this protocol, enabling facile accesses to a range of elongated cyano and/or gem-difluoroalkene-bearing compounds.
- Xia, Peng-Ju,Ye, Zhi-Peng,Hu, Yuan-Zhuo,Song, Dan,Xiang, Hao-Yue,Chen, Xiao-Qing,Yang, Hua
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supporting information
p. 2658 - 2662
(2019/04/25)
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- A convenient access to allylic triflones with allenes and triflyl chloride in the presence of (EtO)2P(O)H
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A simple method for the preparation of allylic triflones from allenes and triflyl chloride in the presence of (EtO)2P(O)H has been developed. The features of this reaction are catalyst-free and simple starting substrates. This method tolerates diverse functional groups and substituted allylic triflones are obtained in moderate to good yields.
- Ni, Jixiang,Jiang, Yong,An, Zhenyu,Lan, Jingfeng,Yan, Rulong
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supporting information
p. 7343 - 7345
(2019/06/27)
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- Oxidative [4+2] Cycloaddition of α-(N-Arylamino) Carbonyls with Aryl Alkenes by Multiple C-H Functionalizations and [1,2]-Aryl Shifts
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A new, general copper-catalyzed oxidative tandem [4+2] cycloaddition of α-(N-arylamino) carbonyl compounds with aryl alkenes to produce highly substituted quinolines has been developed, which allows the formation of three new C-C bonds through a sequence of multiple C-H functionalizations, annulation, and [1,2]-aryl shifts.
- Wei, Wen-Ting,Teng, Fan,Li, Yang,Song, Ren-Jie,Li, Jin-Heng
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supporting information
p. 6285 - 6288
(2019/09/06)
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- Radical C?H Bond Trifluoromethylation of Alkenes by High-Valent Copper(III) Trifluoromethyl Compounds
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A general and selective method is developed that allows direct vinylic C?H bond trifluoromethylation of 1,1-diarylalkenes by a high-valent copper(III) trifluoromethyl complex, producing biologically active trifluoromethylated alkenes (as well as trifluoro
- Zhang, Hao-Ran,Xiao, Chang,Zhang, Song-Lin,Zhang, Xiaoming
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supporting information
p. 5305 - 5310
(2019/11/22)
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- A tailored polymeric cationic tag-anionic Pd(ii) complex as a catalyst for the low-leaching Heck-Mizoroki coupling in flow and in biomass-derived GVL
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The [PdCl4]2- palladium complex has been immobilized on a polystyrene-type resin loaded with pincer-type imidazolium ionic tag binding sites. The catalytic system (Pd(ii)-POLI-TAG) has proved to be highly active in the definition of an efficient protocol for the Heck-Mizoroki coupling reaction under batch and flow conditions. Importantly, it is shown to be highly robust in combination with a safe non-toxic reaction medium, i.e. biomass-derived GVL, since it could be reused for multiple runs without significantly losing its activity.
- Mahmoudi, Hamed,Valentini, Federica,Ferlin, Francesco,Bivona, Lucia Anna,Anastasiou, Ioannis,Fusaro, Luca,Aprile, Carmela,Marrocchi, Assunta,Vaccaro, Luigi
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supporting information
p. 355 - 360
(2019/01/28)
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- SBA-15/POSS-Imidazolium Hybrid as Catalytic Nanoreactor: the role of the Support in the Stabilization of Palladium Species for C?C Cross Coupling Reactions.
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Supported imidazolium modified polyhedral oligomeric silsesquioxanes (POSS) on SBA-15 have been used as platform for Pd(II) species. The so-obtained material was firstly characterized by means of TGA, solid state NMR, TEM, XPS, SAXS, porosimetry and ICP-OES and it was successfully tested as pre-catalyst in C?C cross couplings, namely Suzuki-Miyaura and Heck reactions. In both cases, the solid proved to be highly efficient and easily recoverable from the reaction mixture. The recyclability was verified for up to seven cycles without showing any activity decrease. Interestingly, only Pd(II) was detected in the reused catalyst in the Heck reaction. Therefore, the versatility of the material was investigated by using various aryl halides. Our palladium nanocomposite was able to promote both Suzuki and Heck reactions down to 0.0007 mol% showing outstanding turnover frequency (TOF) values of 114,286 and 32,381 h?1, respectively. Comparison with the palladium catalyst on SiO2-POSS-imidazolium support showed interesting differences in terms of stabilization of Pd species and recyclability. The excellent outcome of the reactions could be ascribed to the textural properties of the SBA-15 support and the presence of the imidazolium-POSS nanocage within the pores of SBA-15, that worked as a sort of nanoreactor. (Figure presented.).
- Calabrese, Carla,Campisciano, Vincenzo,Siragusa, Fabiana,Liotta, Leonarda F.,Aprile, Carmela,Gruttadauria, Michelangelo,Giacalone, Francesco
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p. 3758 - 3767
(2019/05/15)
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- Spherical hollow mesoporous silica supported phosphotungstic acid as a promising catalyst for α-arylstyrenes synthesis via Friedel-Crafts alkenylation
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In this work, a spherical hollow mesoporous silica (SHMS) with high surface area (902 m2/g) and large mesopore volume (1.31 cm3/g) was prepared via a facile and scalable two-step soft-hard dual template-assisted sol-gel approach (OSD
- Wang, Xianhui,Zhao, Zhongkui
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p. 729 - 734
(2018/09/21)
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- Synthesis and characterization of a new zwitterionic palladium complex as an environmentally friendly catalyst for the Heck-Mizoroki coupling reaction in GVL
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A new zwitterionic Palladium (II) complex has been synthesized by the one-pot mixing of Pd(OAc)2, 2-aminophenol and (3-formyl-4-hydroxy-5-methylbenzyl) triphenylphosphonium chloride, in refluxing ethanol. The metal complex formed was characterized by 1H NMR, 13C NMR, 31P NMR and X-ray crystallographic technique and its efficiency tested as a homogeneous pre-catalyst in Heck-Mizoroki cross coupling reaction using γ-Valerolactone (GVL) as a biomass-derived green medium. All the products were obtained in good to excellent yields.
- Bagherzadeh, Mojtaba,Mahmoudi, Hamed,Ataie, Saeed,Bahjati, Mohammad,Kia, Reza,Raithby, Paul R.,Vaccaro, Luigi
-
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- Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ under Acidic Conditions
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A dehydrative cross-coupling of 1-phenylethanol catalysed by sugar derived, in situ formed palladium(0) nanoparticles under acidic conditions is realised. The acidic conditions allow for use of alcohols as a feedstock in metal-mediated coupling reactions via their in situ dehydration and subsequent cross-coupling. Extensive analysis of the size and morphology of the palladium nanoparticles formed in situ showed that the zero-valent metal was surrounded by hydrophilic hydroxyl groups. EDX-TEM imaging studies using a prototype silicon drift detector provided insight into the problematic role of molecular oxygen in the system. This increased understanding of the catalyst deactivation allowed for the development of the cross-coupling methodology. A 250-12,000 fold increase in molar efficiency was observed when compared to related two-step protocols that use alternative feedstocks for the palladium-mediated synthesis of stilbenes. This work opens up a new research area in which the active catalyst is formed, stabilised and regenerated by a renewable sugar.
- Camp, Jason E.,Bousfield, Thomas W.,Dunsford, Jay J.,Adams, James,Britton, Joshua,Fay, Michael W.,Angelis-Dimakis, Athanasios
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supporting information
p. 3862 - 3874
(2018/09/29)
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- Synthetic method of 1,1-diarylethenes derivative
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The invention discloses a synthetic method of a 1,1-diarylethenes derivative. The synthetic method comprises the following steps: with cinnamic acid derivatives and aryltriethoxysilane as raw materials, mixing the raw materials with a catalyst, an oxidizing agent, a ligand, an additive and alkali; carrying out reaction for 2 to 24 hours at 100 to 160 DEG C under argon protection in a reaction solvent so as to prepare a target compound. Because cinnamic acid is common unsaturated carboxylic acid, the preparation is convenient, cinnamic acid is cheap and easy to obtain; because aryltriethoxysilane is common organosilane in organic chemistry, aryltriethoxysilane is cheap and easy to obtain, is higher in stability and has little impact on an environment; therefore, the 1,1-diarylethenes derivative is synthesized by carrying out coupled reaction between the selected aryltriethoxysilane and the cinnamic acid derivatives. The synthetic method has the advantages of cheap and easy availabilityof the raw materials and low production cost; meanwhile, an experiment is easy to operate, and the synthetic method can be developed as an industrialized production method. According to the syntheticmethod disclosed by the invention, synthetic conditions are also screened and optimized, so that the reaction yield is further improved.
- -
-
Paragraph 0043; 0048; 0056; 0068; 0071; 0079; 0094; 0095
(2018/10/11)
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- A Palladium NNC-Pincer Complex as an Efficient Catalyst Precursor for the Mizoroki?Heck Reaction
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The Mizoroki?Heck reaction of aryl halides (iodides, bromides, or chlorides) with activated alkenes in the presence of a palladium NNC-pincer complex at ppb to ppm loadings gave the corresponding internal alkenes in excellent yields. The total turnover number and turnover frequency reached up to 8.70×108 and 1.21×107 h?1 (3.36×103 s?1), respectively. The catalyst was applied in a ten-gram-scale synthesis of the UV-B sunscreen agent octinoxate (2-ethylhexyl 4-methoxycinnamate). Reaction-rate analyses, transmission electron microscopic examination of the reaction mixture, and poisoning tests suggested that a monomeric palladium species is the catalytically active species in the catalytic cycle. (Figure presented.).
- Hamasaka, Go,Ichii, Shun,Uozumi, Yasuhiro
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supporting information
p. 1833 - 1840
(2018/04/05)
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- Stilbene synthesis through decarboxylative cross-coupling of substituted cinnamic acids with aryl halides
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The Pd-catalyzed decarboxylative cross-coupling reaction between cinnamic acid and aryl iodide derivatives was studied using both homogeneous and heterogeneous Pd-catalysts. It was demonstrated that simple Pd(OAc)2 can catalyze this reaction wi
- Rameau, Nelly,Russo, Baptiste,Mangematin, Stéphane,Pinel, Catherine,Djakovitch, Laurent
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p. 132 - 143
(2018/05/22)
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- Palladium nanoparticles immobilized on halloysite nanotubes covered by a multilayer network for catalytic applications
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The synthesis of pure fine chemicals for industrial purposes is one of the most attractive challenges of chemical research. The use of catalytic pathways mediated by palladium nanoparticles (PdNPs) for C-C bond formation is a useful way to obtain these kinds of compounds. To achieve this objective, the PdNPs can be efficiently loaded on a functionalized natural nanostructured support such as halloysite nanotubes (HNTs). Hybrid materials based on thiol functionalized halloysite nanotubes and highly cross-linked imidazolium salts were successfully developed and used for the stabilization of PdNPs. The HNT/Pd hybrids were thoroughly characterized from a physico-chemical point of view and tested as a catalyst in the Suzuki and Heck C-C coupling reactions under microwave irradiation to obtain innovative materials for fine chemicals synthesis. Catalytic tests highlighted the fact that the HNT/Pd hybrids show high performance and full recyclability (up to ten cycles) in both reactions. Regarding the Suzuki reaction, under the best experimental conditions, the remarkable values of a turnover number of 194?000 and a turnover frequency of 3?880?000 h-1 were achieved without metal contamination in the final products.
- Massaro, Marina,Colletti, Carmelo G.,Buscemi, Gabriella,Cataldo, Salvatore,Guernelli, Susanna,Lazzara, Giuseppe,Liotta, Leonarda F.,Parisi, Filippo,Pettignano, Alberto,Riela, Serena
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supporting information
p. 13938 - 13947
(2018/08/21)
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- Mn(OAc)3-Mediated Synthesis of 3-Phosphonyldihydrofurans from β-Ketophosphonates and Alkenes
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A new, general method for the synthesis of 3-phosphonyldihydrofuran derivatives has been achieved through Mn(OAc)3-mediated radical cyclization between β-ketophosphonates and alkenes. This transformation allows the direct formation of C-C/C-O bonds and the construction of a dihydrofuran ring in one reaction with operational simplicity and excellent functional-group compatibility.
- Lu, Guozhang,Lin, Binzhou,Gao, Yuzhen,Ying, Jianxi,Tang, Guo,Zhao, Yufen
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p. 724 - 728
(2017/03/21)
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- α,α-Diarylethylene Glycols as Valuable Precursor for Synthesis of 1,1-Diarylethenes and α,α-Diaryl Acetaldehydes
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Towards assembling of diarylmethine unit present in biologically important molecules, we have developed a new Weinreb Amide (WA) based building block derived from glycolic acid. The WA functionality present in this building block permits the sequential addition of various arylmagnesium bromide reagents in a controlled manner that enables assembly of a diarylmethine unit. The developed synthetic route provides easy access to important diarylethenes and α,α-diarylethylene glycols. The synthesized α,α-diarylethylene glycols provide access to synthetically important symmetrical and unsymmetrical α,α-diaryl acetaldehydes as valuable intermediates.
- Tiwari, Praveen Kumar,Sivaraman, Balasubramaniam,Aidhen, Indrapal Singh
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p. 3594 - 3605
(2017/07/22)
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- Nickel-Catalyzed Direct Synthesis of Aryl Olefins from Ketones and Organoboron Reagents under Neutral Conditions
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Nickel-catalyzed addition of arylboron reagents to ketones results in aryl olefins directly. The neutral condition allows acidic protons of alcohols, phenols, and malonates to be present, and fragile structures are also tolerated.
- Lei, Chuanhu,Yip, Yong Jie,Zhou, Jianrong Steve
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supporting information
p. 6086 - 6089
(2017/05/08)
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- Iodine-catalyzed transformation of aryl-substituted alcohols under solvent-free and highly concentrated reaction conditions
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Iodine-catalyzed transformations of alcohols under solvent-free reaction conditions (SFRC) and under highly concentrated reaction conditions (HCRC) in the presence of various solvents were studied in order to gain insight into the behavior of the reaction intermediates under these conditions. Dimerization, dehydration and substitution were the three types of transformations observed with benzylic alcohols. Dimerization and substitution reactions were predominant in the case of primary- and secondary alcohols, whereas dehydration prevailed in the case of tertiary alcohols. The relative reactivity of substituted 1-phenylethanols in I2-catalyzed dimerization under SFRC provided a good Hammett plot ρ+ = -2.8 (r2 = 0.98), suggesting the presence of electron-deficient intermediates with a certain degree of developed charge in the rate-determining step.
- Jereb, Marjan,Vra?i?, Dejan
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p. 747 - 762
(2018/01/17)
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- Well-defined palladium(0) complexes bearing N-heterocyclic carbene and phosphine moieties: Efficient catalytic applications in the Mizoroki-Heck reaction and direct C-H functionalization
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Two series of well-defined palladium(0) complexes with phosphine-functionalized N-heterocyclic carbene ligands were prepared. These complexes featured six- and seven-membered chelate rings in the two series. Among the seven-membered chelate complexes, those featuring the PCy2 moiety exhibited observable fluxional behavior on the NMR time scale, corresponding to the interchange between two sets of conformations. Most of these novel complexes were successfully structurally characterized by single-crystal X-ray diffraction studies. These two series of palladium(0) complexes were tested for their potential catalytic applications in two mechanistically distinct reactions, namely, Mizoroki-Heck coupling and direct C-H functionalization reactions. One of the six-membered chelate complexes was found to be an efficient pre-catalyst for mediating the coupling reactions between aryl chlorides and alkenes. The palladium(0) complex could also be effectively applied in the direct C-H functionalization reactions of aryl bromides with 1,2-dimethylimidazole.
- Lee, Jhen-Yi,Shen, Jiun-Shian,Tzeng, Ru-Jiun,Lu, I-Chen,Lii, Jenn-Huei,Hu, Ching-Han,Lee, Hon Man
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p. 10375 - 10388
(2016/07/06)
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- Efficient Catalyst for Both Suzuki and Heck Cross-Coupling Reactions: Synthesis and Catalytic Behaviour of Geometry- Constrained Iminopyridylpalladium Chlorides
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A series of geometry-constrained iminopyridyl-palladium chlorides were synthesized and characterized. These phosphine-free palladium complexes were explored for their catalytic activities in both Suzuki and Heck cross-coupling reactions, achieving turnover numbers as high as 106towards various aryl bromides, even those containing various functionalities. In addition, the influence of substituents with steric and electronic factors was reflected by the differences observed in their activities. (Figure presented.).
- Tang, Yujie,Zeng, Yanning,Hu, Qingxia,Huang, Fang,Jin, Liqun,Mo, Weimin,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan,Sun, Wen-Hua
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p. 2642 - 2651
(2016/08/31)
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- Branched Arylalkenes from Cinnamates: Selectivity Inversion in Heck Reactions by Carboxylates as Deciduous Directing Groups
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A decarboxylative Mizoroki–Heck coupling of aryl halides with cinnamic acids has been developed in which the carboxylate group directs the arylation into its β-position before being tracelessly removed through protodecarboxylation. In the presence of a copper/palladium catalyst, both electron-rich and electron-deficient aryl bromides and chlorides bearing numerous functionalities were successfully coupled with broadly available cinnamates, with selective formation of 1,1-disubstituted alkenes. This reaction concept, in which the carboxylate acts as a deciduous directing group, ideally complements traditional 1,2-selective Heck reactions of styrenes.
- Tang, Jie,Hackenberger, Dagmar,Goossen, Lukas J.
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supporting information
p. 11296 - 11299
(2016/10/13)
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- Traceless directing group mediated branched selective alkenylation of unbiased arenes
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Owing to the synthetic importance of branched olefinated products, we report palladium catalyzed formation of branched olefins facilitated by a C-H activation based protocol. This involves selective insertion of olefins and subsequent decarboxylation using a completely unbiased benzene ring as the starting precursor. The significance of the protocol has been further highlighted by exhibition of functionality tolerance along with a late-stage modification of the branched olefinated products leading to the formation of other functionalized molecules.
- Agasti, Soumitra,Dey, Aniruddha,Maiti, Debabrata
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supporting information
p. 12191 - 12194
(2016/10/21)
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- METHOD FOR COUPLING A FIRST COMPOUND TO A SECOND COMPOUND
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The present disclosure describes a method of coupling a first compound to a second compound, the method comprising: providing the first compound having a fluorosulfonate substituent; providing the second compound comprising an alkene; and reacting the first compound and the second compound in a reaction mixture, the reaction mixture including a catalyst having at least one group 10 atom, the reaction mixture under conditions effective to couple the first compound to the second compound.
- -
-
Paragraph 0054; 0055; 0056
(2016/05/02)
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- Olefin synthesis by the Pd-catalyzed cross coupling on sulfonylhydrazones with aromatic sulfinates
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This Letter describes the synthesis of olefins by coupling of electron deficient sulfonylhydrazones with aryl sulfinate salts in the presence of a palladium(II) catalyst under aerobic conditions. This methodology obviates the need for preparation of an organometallic and separate activation of the ketone starting material via a vinyl halide or triflate. The oxidant, reagent stoichiometry, and the electronics of the sulfinate coupling partner are reported.
- Tan, Hongyu,Houpis, Ioannis,Li, Yunfei,Wang, Youchu,Liu, Renmao,Chen, Zhilong
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p. 2336 - 2340
(2016/05/10)
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- Metal-free oxidative cross-coupling of diazirines with arylboronic acids
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We report herein a metal-free cross-coupling of diazirines with arylboronic acids under oxidative conditions. The reaction affords a series of substituted olefins. It is proposed that the interaction between the nitrogen on diazirine with arylboronic acid plays a key role in this transformation.
- Wu, Guojiao,Zhao, Xia,Ji, Wenzhi,Zhang, Yan,Wang, Jianbo
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p. 1961 - 1963
(2016/02/05)
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- Al(OTf)3: An efficient lewis acid additive for domino addition-elimination of Grignard reagents to activated ketones
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It has been demonstrated that aluminium triflate in either stoichiometric or catalytic quantities facilitates the addition-elimination of Grignard reagents to electron-rich ketones, such as methoxy substituted acetophenones, propiophenone and chromanone in a one-pot process, and that it has an enhancing effect on the addition of these reagents to the ketones. It has also been found that the reactions are highly stereoselective towards one regioisomer of the alkene in the case of oxygenated aryl-alkyl substituted substrates, but not when the elimination originates from a double benzylic alcohol intermediate.
- Pieterse, Tanya,Visser, Melanie,Marais, Charlene,Bezuidenhoudt, Barend C. B.
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supporting information
p. 1541 - 1546
(2016/06/14)
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- Preparations of Saturated N-P-N Type Secondary Phosphine Oxides and their Applications in Cross-Coupling Reactions
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A series of cyclohexane-1,2-diamine (3a-3d) and benzene-1,2-diamine derivatives (3e-3h) were pre- pared. Followed by hydrolysis, the reaction of 3a-3c with PCl3 successfully led to the formation of cor- responding metastable saturated heteroato
- Chang, Yu-Chang,Liang, Ya-Han,Hong, Fung-E
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p. 353 - 367
(2016/05/09)
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- Synthesis of 1,3-Substituted Cyclobutanes by Allenoate-Alkene [2 + 2] Cycloaddition
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A method for the [2 + 2] cycloaddition of terminal alkenes with allenoates is presented. This process allows for the rapid synthesis of 1,3-substituted cyclobutanes in high yield under simple and robust reaction conditions.
- Conner, Michael L.,Brown, M. Kevin
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p. 8050 - 8060
(2016/09/09)
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- Tuning of the textural features and acidic properties of sulfated mesoporous lanthana-zirconia solid acid catalysts for alkenylation of diverse aromatics to their corresponding α-arylstyrenes
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The textural features and acidic properties of sulfated mesoporous lanthana-zirconia solid acids (SO42?/meso-La0.1Zr0.9Oδ) were efficiently tuned by modifying the conditions used to prepare the meso-La0.1Zr0.9Oδ composites, such as the molar ratio of the template to La and Zr metal ions (Nt/m), molar ratio of ammonia to La and Zr metal ions (Na/m), hydrothermal temperature (Thydro), and hydrothermal time (thydro). The effect of the textural features and acidic properties on the catalytic performance of solid acid catalysts for alkenylation of p-xylene with phenylacetylene was investigated. Various characterization techniques such as N2 physisorption, X-ray diffraction, NH3 temperature-programmed desorption, and thermogravimetric analysis were employed to reveal the relationship between the nature of catalyst and its catalytic performance. It was found that the catalytic performance significantly depended on the textural features and acidic properties, which were strongly affected by preparation conditions of the meso-La0.1Zr0.9Oδ composite. Appropriate acidic sites and high accessibility were required to obtain satisfactory catalytic reactions for this reaction. It was also found that the average crystallite size of t-ZrO2 affected by the preparation conditions had significant influence on the ultrastrong acidic sites of the catalysts. The optimized SO42?/meso-La0.1Zr0.9Oδ catalyst exhibited much superior catalytic activity and coke-resistant stability. Moreover, the developed SO42?/meso-La0.1Zr0.9Oδ catalyst demonstrated excellent catalytic performance for alkenylation of diverse aromatics with phenylacetylene to their corresponding α-arylstyrenes. Combining the previously established complete regeneration of used catalysts by a facile calcination process with the improved catalytic properties, the developed SO42?/meso-La0.1Zr0.9Oδ solid acid could be a potential catalyst for industrial production of α-arylstyrenes through clean and atom efficient solid-acid-mediated Friedel-Crafts alkenylation of diverse aromatics with phenylacetylene.
- Zhao, Zhongkui,Ran, Jinfeng,Guo, Yongle,Miao, Boyuan,Wang, Guiru
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p. 1303 - 1313
(2016/09/07)
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- Supported phosphotungstic acid catalyst on mesoporous carbon with bimodal pores: A superior catalyst for Friedel-Crafts alkenylation of aromatics with phenylacetylene
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Supported phosphotungstic acid (PTA) catalysts on diverse carriers containing the modified commercially available activated carbon (AC), classical mesoporous carbon via SBA-15 hard template method (CMK-3), and the mesoporous carbon with high surface area and bimodal pores through evaporation-induced tri-constituent co-assembly approach (MC) by using a facile wet impregnation method were employed as solid acid catalysts for Friedel-Crafts alkenylation of p-xylene with phenylacetylene. N2 adsorption–desorption, X-ray diffraction (XRD), and NH3 temperature-programmed desorption (NH3-TPD) characterization techniques were employed to reveal the structure-performance relationship. PTA/MC exhibits much superior catalytic performance to the previously reported PTA/AC, and even to PTA/CMK-3. The PTA/MC catalysts were optimized by varying the PTA loading, and the optimum PTA loading is 35%. The close to 100% of conversion towards phenylacetylene can be achieved in the presence of 2.67% of the 35% PTA/MC solid acid catalyst. It is also found that catalytic properties of the solid acids are strongly depended on acidic properties that affected by the textural properties of supports and PTA loading, as well as the accessibility of active sites affected by specific surface area and pore structure of catalyst. Moreover, the 35?wt.% PTA/MC catalyst has demonstrated outstanding catalytic performance for the Friedel-Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes.
- Zhao, Zhongkui,Wang, Xianhui
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p. 139 - 146
(2016/09/02)
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- A macrocyclic Pd(II)-Ni(II) complex in Heck and Suzuki reactions
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A heterodinuclear Pd(II)-Ni(II) macrocyclic Schiff base complex was applied as a catalyst for Heck and Suzuki cross-coupling reactions. In reaction of 4-bromoanisole with styrene, 4-methoxy-trans-stilbene was formed as the main product with a yield of up to 87%. In the Suzuki coupling of 4-bromoanisole with PhB(OH)2in a 2-propanol/water solution, up to 96% of the product was obtained. Analyses of the post-reaction mixtures confirmed the high stability of the macrocyclic Pd(II)-Ni(II) complex under the reaction conditions. The partial decomposition of the complex started at the Ni(II) site.
- Mieczyńska, Ewa,Lisowski, Jerzy,Trzeciak, Anna M.
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p. 145 - 149
(2015/02/19)
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- Catalytic nucleophilic addition of olefinic C-H bond to α,β-unsaturated-γ-lactams
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A novel catalytic nucleophilic addition of olefins to α,β-unsaturated-γ-lactams has been developed with a cyclic N-acyliminium ion as a key intermediate. It provides an efficient approach to 5-alkenyl-2-pyrrolidinones from simple and readily available starting materials and the desired products could be obtained in moderate to good yields (23-85%).
- Wang, Maorong,Gao, Bao,Huang, Hanmin
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supporting information
p. 5533 - 5536
(2015/09/21)
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- Olefin Preparation via Palladium-Catalyzed Oxidative De-Azotative and De-Sulfitative Internal Cross-Coupling of Sulfonylhydrazones
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A novel reactivity of sulfonylhydrazones under Pd catalysis is described, where SO2 and N2 are formally extruded to afford the product of an apparent internal coupling reaction. The reaction is effective with both carbocyclic and heterocyclic aromatic precursors.
- Tan, Hongyu,Houpis, Ioannis,Liu, Renmao,Wang, Youchu,Chen, Zhilong
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supporting information
p. 3548 - 3551
(2015/07/28)
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- Synthesis and isolation of an acyclic tridentate bis(pyridine)carbodicarbene and studies on its structural implications and reactivities
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The simple synthetic development of acyclic pincer bis(pyridine)carbodicarbene is depicted herein. Presented is the first isolated structural pincer carbodicarbene with a C-C-C angle of 143°, larger than the monodentate framework. More importantly, theore
- Hsu, Yu-Chen,Shen, Jiun-Shian,Lin, Bo-Chao,Chen, Wen-Ching,Chan, Yi-Tsu,Ching, Wei-Min,Yap, Glenn P. A.,Hsu, Chao-Ping,Ong, Tiow-Gan
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supporting information
p. 2420 - 2424
(2015/02/19)
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- Electrophilic Fluorophosphonium Cations in Frustrated Lewis Pair Hydrogen Activation and Catalytic Hydrogenation of Olefins
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The combination of phosphorus(V)-based Lewis acids with diaryl amines and diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal-free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair type activation mechanism. FLP hydrogenation: The combination of a phosphorus(V)-based Lewis acid with diaryl amines or diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal-free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair (FLP)-type activation mechanism.
- Vom Stein, Thorsten,Perz, Manuel,Dobrovetsky, Roman,Winkelhaus, Daniel,Caputo, Christopher B.,Stephan, Douglas W.
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supporting information
p. 10178 - 10182
(2015/09/01)
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- Supported phosphotungstic acid catalyst on modified activated carbon for Friedel-Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes
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Abstract The supported phosphotungstic acid catalysts on modified activated carbon (PTA/AC) prepared by a facile wet impregnation method were employed for Friedel-Crafts alkenylation of diverse aromatics with phenylacetylene to synthesize their corresponding α-arylstyrenes. Reaction results demonstrate that the fabricated PTA/AC catalyst with 30 wt.% PTA loading exhibits outstanding catalytic performance. The 100% conversion of phenylacetylene with 95.7% selectivity towards α-(2,5-dimethylphenyl) styrene can be achieved over the developed 30 wt.% PTA/AC catalyst under optimized reaction conditions, and no visible loss in catalytic performance can be observed after it suffers from several times recycling. The various characterization techniques including X-ray diffraction, N2 adsorption-desorption, Fourier transform infrared spectroscopy, and NH3 temperature-programmed desorption were employed to reveal the relationship between the catalysts nature and catalytic properties. Moreover, the results on the scope of aromatics for the Friedel-Crafts alkenylation illustrate that the developed PTA/AC alkenylation catalyst can be efficiently catalyze the diverse aromatics and even for the electron deficient chlorobenzene. The developed PTA/AC catalyst, using the modified low-cost and sustainable AC as support, may be a robust and promising candidate for highly-efficient and clean α-arylstyrenes production through Friedel-Crafts alkenylation of diverse aromatics including electron-donating and electron-withdrawing groups substituted benzene derivatives as well as heterocyclic and polypolycyclic arenes with phenylacetylene.
- Zhao, Zhongkui,Wang, Xianhui
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p. 103 - 110
(2015/08/06)
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- Immobilized palladium nanoparticles on potassium zirconium phosphate as an efficient recoverable heterogeneous catalyst for a clean Heck reaction in flow
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Palladium nanoparticles on layered potassium α-zirconium phosphate (PdNP/α-ZrPK) with high palladium loading (10.6 wt%) have been prepared and used as catalyst in low amount (0.1 mol% of Pd) in the Heck reaction of methyl acrylate and styrene with a series of aryl iodides in CH3CN/H2O azeotrope as a green medium. The procedure has been optimized under flow conditions obtaining an extremely low waste production (E-factor) and allowing to isolate the final product with very low residual palladium content without any purification step.
- Petrucci, Chiara,Cappelletti, Matteo,Piermatti, Oriana,Nocchetti, Morena,Pica, Monica,Pizzo, Ferdinando,Vaccaro, Luigi
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- Efficient synthesis of polysubstituted olefins using stable palladium nanocatalyst: Applications in synthesis of tamoxifen and isocombretastatin A4
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A phosphine-free stable palladium nanocatalyst was used for an efficient synthesis of polysubstituted olefins from N-tosylhydrazones and aryl iodides. This methodology was successfully utilized in the synthesis of biologically important tamoxifen and isocombretastatin A4. The nanocatalyst was easily recovered and reused without any apparent loss in size and catalytic activity.
- Ganapathy, Dhandapani,Sekar, Govindasamy
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supporting information
p. 3856 - 3859
(2014/08/18)
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- Metal-free Mizoroki-Heck type reaction: A radical oxidative coupling reaction of 2-chloro-dithiane with substituted olefins
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An efficient metal-free Mizoroki-Heck type reaction of di- and tri-substituted alkenes with 2-chloro-dithiane has been developed under ambient pressure of air or using a relatively low loading of BF3·Et2O. This study represents a new environmentally friendly method for the syntheses of dithianyl-substituted alkene derivatives via a radical oxidative coupling process.
- Du, Wenbin,Lai, Junshan,Tian, Lixia,Xie, Xingang,She, Xuegong,Tang, Shouchu
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p. 14017 - 14020
(2015/01/16)
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- AIBN-catalyzed oxidative cleavage of gem -disubstituted alkenes with O 2 as an oxidant
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A 2,2-azobis(isobutyronitrile) (AIBN) catalyzed oxidative cleavage of gem-disubstituted alkenes with molecular oxygen as the oxidant has been described. Carbonyl compounds were obtained as the desired products in high yield under mild conditions. Based on previous documents and current experimental results, a relatively reasonable mechanism is proposed.
- Wang, Guang-Zu,Li, Xing-Long,Dai, Jian-Jun,Xu, Hua-Jian
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p. 7220 - 7225
(2014/08/18)
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