cas 3218-36-8, 4-Biphenylcarboxaldehyde | Articles data

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Highly efficient polymer-based nanoreactors for selective oxidation of alcohols in water
In this study, we demonstrate the fabrication of thermo-responsive polymer-based TEMPO nanoreactors and their application in the catalytic selective oxidation of alcohols as a highly efficient and recoverable catalyst in aqueous media. First, a diblock amphiphilic copolymer NHS-P(MMA25-b-OEGMA75) consisting of poly(methyl methacrylate) (PMMA) and poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA300) with a terminal N-hydroxysuccinimide (NHS) activated ester was synthesized utilizing reversible addition–fragmentation chain transfer polymerization (RAFT) techniques. Free radical 2,2,6,6,-tetramethyipiperidinooxy (TEMPO) was then introduced into the end of the copolymer based on activated ester functionalization to afford the temperature responsive polymer-supported catalyst TEMPO-P(MMA25-b-OEGMA75). Next, core-shell TEMPO nanoreactors were formed through self-assembly of the amphiphilic block polymers in deionized water. The morphology of the nanoreactors was well characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The nanoreactors were then successfully applied in the selective oxidative of alcohols in water. A variety of aldehydes and ketones were achieved in excellent yields and selectivities in high reaction rates with low catalyst loading. The high efficiency in catalysis of the nanoreactors may attributed to the ideal environment where enhancing the interactions between the catalyst and the alcohol substrate, mimicking the environment of enzymes. The thermo-responsive polymer-based nanoreactors could be conveniently recovered in the temperature above the LCST of the polymer after extraction of product from the reaction mixture. This strategy provides an effective and cleaner way for the selective oxidative of alcohols in organic synthesis and industrial application.
Chen, Tao,Xu, Zhenkai,Zhou, Lei,Qiu, Jiaqi,Wang, Maolin,Wang, Jiping
(2019)
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Azo-azomethine based palladium(II) complexes as catalysts for the Suzuki-Miyaura cross-coupling reaction
Seven azo-azomethine ligands (2-8) have been synthesized from the reaction of (E)-5-((4-chlorophenyl)diazenyl)-2-hydroxybenzaldehyde with different aniline derivatives. Ligand structures were characterized by the combination of IR, UV–Visible spectroscopy
Da?, Ay?e Kazanc?,Evren, Enes,Gürbüz, Nevin,Ikiz, Mesut,Inan, Ay?e,Ispir, Esin,K?se, Muhammet,Ozdemir, ?smail,Sünbül, Ali Burak
(2020)
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Synthesis, characterization and theoretical and fluorescence emission microscopy studies of new Pd/Pt–cyclopropa[60]fullerene complexes: Application of Taguchi method for optimization of parameters in Suzuki–Miyaura reaction
The reactions of unsymmetric phosphorus ylides of the type [Ph2P(CH2)nPPh2?C(H)C(O)C6H4-p-CN] (n?=?1 (Y1); n?=?2 (Y2)) with C60 and M(dba)2 (M?=?Pd or Pt; dba?=?dibenzylideneacetone) are reported. Based on the various coordination modes of these ylides in complexation, the following new Pd/Pt–cyclopropa[60]fullerene complexes were obtained: P,C-coordinated [(η2-C60)Pd(κ2-Y1)] (1) and [(η2-C60)Pt(κ2-Y1)] (2) complexes and P-coordinated [(η2-C60)Pd(Y2)2] (3) and [(η2-C60)Pt(Y2)2] (4) complexes. These compounds were characterized using Fourier transform infrared, UV–visible and NMR (1H, 13C and 31P) spectroscopies and scanning electron microscopy. Furthermore, cytotoxicity studies showed that nanoparticles of these complexes can be used as non-toxic labels for cellular imaging application. Also energy decomposition analysis results revealed that the percentage contribution of ΔEelec in total interaction energy is considerably larger than that of ΔEorb. Thus, in all complexes the (η2-C60)M?(Y1) bond is considerably more electrostatic in nature than the (η2-C60)?M(Y1) bond. Finally, by application of the Taguchi method for optimization of parameters in Suzuki–Miyaura reaction, the catalytic activity of Pd complexes 1 and 3 was investigated in the cross-coupling reaction of various aryl chlorides with phenylboronic acid. According to analysis of variance results, solvent has the highest F value and it has high contribution percentage (36.75%) to the yield of Suzuki–Miyaura reaction.
Sabounchei, Seyyed Javad,Badpa, Khadijeh,Hashemi, Ali,Salehzadeh, Sadegh,Maleki, Farahnaz,Hosseinzadeh, Leila
(2018)
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Fluoride-triggered indium-mediated synthesis of (hetero)biaryls
A simple method for the preparation of triorganoindium reagents under mild conditions based in indium-silicon exchange is described.
Font-Sanchis, Enrique,Sastre-Santos, Angela,Fernandez-Lazaro, Fernando
p. 2470 - 2473
(2009)
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Palladium(II) catalyzed Suzuki C–C coupling reactions with imino- and amino-phosphine ligands
A new series of bidentate PN type imino- (1–3) and amino-phosphine ligands (4–6) and their palladium(II) complexes [Pd(PN)Cl2] (1a–6a) have been synthesized and fully characterized using spectroscopic and analytical methods, including 31P, 1H, 13C NMR and FTIR spectroscopy and high resolution mass spectroscopy. The catalytic activities of the Pd(II) complexes were investigated for the Suzuki C–C coupling reactions of phenylboronic acid with aryl bromides using a substrate to catalyst ratio of 500/1. The effect of base, temperature and solvent has been investigated, and the highest reaction rates were observed at 80 °C in dimethylformamide (DMF) with K2CO3 as the base in 12 h. Under optimized reaction conditions, generally higher coupled product was obtained with substituted aryl bromides, including both electron-withdrawing (-formyl and -aceto) or -donating groups (-methyl and -methoxy) at -ortho or -para positions, except 2-bromoacetophenone which has bulkier -aceto group compared to the other aryl bromides.
Kemal Y?lmaz, Mustafa,?nce, Simay,Y?lmaz, Sevilay,Kele?, Mustafa
p. 252 - 258
(2018)
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Polymer supported palladium complex as a reusable catalyst for Suzuki coupling
Novel, simple and efficient catalytic system based on a polymer supported Pd complex of 2,6-bis(benzimidazolyl)pyridine, Pd(PS–BBP)Cl2, was found to be highly active for Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acids under mild conditions. The catalyst was characterized by CHN analyses, thermogravimetric analyses, BET surface area measurements, ICP-OES, FT-IR and electronic spectral studies. The effect of solvent, base, temperature and catalyst concentration on the coupling reaction of iodobenzene with phenylboronic acid was also investigated. A variety of functional groups are tolerated. The novel catalyst could be recovered in a facile manner from the reaction mixture and could be reused up to seven times without significant loss of catalytic activity.
Renuka,Gayathri
p. 26 - 31
(2018)
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Nitrogen-rich porous covalent imine network (CIN) material as an efficient catalytic support for C-C coupling reactions
In an effort to expand the realm of possibilities of nitrogen-rich porous materials that could be used in catalysis, herein we report the synthesis of a new highly nitrogen rich (ca. 45%) porous covalent imine network (CIN-1) material employing simple Schiff base chemistry and further grafting its surface with palladium. Pd-loaded CIN-1 support acts as a truly heterogeneous catalyst towards Suzuki C-C coupling reaction between aryl halides with arylboronic acids. High surface area and excellent accessibility of the catalytic sites make it very efficient for heterogeneous catalysis. The stability of the catalyst due to intimate contact between nitrogen-rich organic support and metal allows several reuses with only a minor loss in catalytic activity.
Bhunia, Manas K.,Das, Swapan K.,Pachfule, Pradip,Banerjee, Rahul,Bhaumik, Asim
p. 1304 - 1311
(2012)
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Pd nanoparticles embedded in mesoporous carbon: A highly efficient catalyst for Suzuki-Miyaura reaction
Mesoporous carbon functionalized with Pd nanoparticles (Pd@MC) was synthesized via one-pot method using SBA-15, furfuryl alcohol and PdCl2 as a template, a carbon source and a palladium source, respectively. The HRTEM image shows that Pd nanoparticles are homogeneously distributed on the surface of nanoporous carbon whereas the XPS spectrum of the catalyst indicates that Pd exists in the form of Pd (0). With a low loading of the catalyst (2 mol% Pd), Pd@MC shows a high conversion (100%) and selectivity for the desired product (>95%) in the Suzuki-Miyaura reactions of acyl halides with phenylboronic acid under a mild reaction condition. The catalyst was found to be highly active and no leaching in the reaction is observed. The catalyst can further be recycled for up to three times without loss of reactivity.
Zhong, Lin,Chokkalingam, Anand,Cha, Wang S.,Lakhi, Kripal S.,Su, Xiangyang,Lawrence, Geoffrey,Vinu, Ajayan
p. 195 - 198
(2015)
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Synthesis and characterization of a supported Pd complex on volcanic pumice laminates textured by cellulose for facilitating Suzuki-Miyaura cross-coupling reactions
Herein, a novel high-performance heterogeneous catalytic system made of volcanic pumice magnetic particles (VPMP), cellulose (CLS) natural polymeric texture, and palladium nanoparticles (Pd NPs) is presented. The introduced VPMP@CLS-Pd composite has been designed based on the principles of green chemistry, and suitably applied in the Suzuki-Miyaura cross-coupling reactions, as an efficient heterogeneous catalytic system. Concisely, the inherent magnetic property of VPMP (30 emu g-1) provides a great possibility for separation of the catalyst particles from the reaction mixture with great ease. In addition, high heterogeneity and high structural stability are obtained by this composition resulting in remarkable recyclability (ten times successive use). As the main catalytic sites, palladium nanoparticles (Pd NPs) are finely distributed onto the VPMP@CLS structure. To catalyze the Suzuki-Miyaura cross-coupling reactions producing biphenyl pharmaceutical derivatives, the present Pd NPs were reduced from chemical state Pd2+ to Pd0. In this regard, a plausible mechanism is submitted in the context as well. As the main result of the performed analytical methods (including FT-IR, EDX, VSM, TGA, FESEM, TEM, BTE, and XPS), it is shown that the spherical-shaped nanoscale Pd particles have been well distributed onto the surfaces of the porous laminate-shaped VPMP. However, the novel designed VPMP@CLS-Pd catalyst is used for facilitating the synthetic reactions of biphenyls, and high reaction yields (～98percent) are obtained in a short reaction time (10 min) by using a small amount of catalytic system (0.01 g), under mild conditions (room temperature).
Soltani, Siavash Salek,Taheri-Ledari, Reza,Farnia, S. Morteza F.,Maleki, Ali,Foroumadi, Alireza
p. 23359 - 23371
(2020)
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Palladium-catalyzed Suzuki-Miyaura reaction of aryl chlorides in aqueous media using tetrahydrodiazepinium salts as carbene ligands
A highly effective, easy to handle, and environmentally benign process for palladium-mediated Suzuki cross-coupling was developed. The in situ prepared three-component system of Pd(OAc)2, 1,3-dialkyltetrahydrodiazepinium chlorides (2a-e), and K
?zdemir, Ismail,Gürbüz, Nevin,G?k, Yetkin,?etinkaya, Engin,?etinkaya, Bekir
p. 2394 - 2396
(2005)
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In situ preparation of palladium / N-heterocyclic carbene complexes and use for Suzuki reaction
The in situ prepared three component system Pd(OAc)2, 1,3-dialkylbenzimidazolium halides (1a-e) and t-BuOK catalyses quantitatively the Suzuki cross-coupling of deactivated aryl chloride substrates. 1,3-Dialkylbenzimidazolium salts (1a-e) were
Oezdemir, Ismail,Goek, Yetkin,Guerbuez, Nevin,Cetinkaya, Engin,Cetinkaya, Bekir
p. 303 - 306
(2005)
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Phosphotungstic acid supported on magnetic nanoparticle used as selective and reusable photocatalyst for aerobic oxidation of benzylic alcohols
An efficient and selective photochemical method for the oxidation of benzylic alcohols has been achieved using phosphotungstic acid supported on imidazole functionalized silica coated cobalt ferrite nanoparticles as a magnetically photocatalyst in acetonitrile with O2. The photocatalyst has been reused several times, without observable loss of activity and selectivity. Results showed this heterogeneous photocatalyst is more active than the unsupported H3PW12O40.
Afshari, Mozhgan,Gorjizadeh, Maryam,Afshar, Ghazal
p. 1675 - 1681
(2013)
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Pd(II)-Metalated and l-Proline-Decorated Multivariate UiO-67 as Bifunctional Catalyst for Asymmetric Sequential Reactions
The construction of a multifunctional catalyst for multistep sequentialtandem reactions at the molecular level faces a formidable challenge. Multivariate (MTV)-MOFs can provide a facile and tunable platform for rationally designing such multifunctional catalysts via grafting different catalytic groups on the bridging ligands. However, the related investigations are still limited. Here, Pd(II) and l-proline are metalated and decorated to organic linkers, respectively, to build a MTV-MOF, which is then successfully applied to sequential Suzuki Coupling/asymmetric Aldol reactions with satisfied coupling performance (yields up to 99%) and good enantioselectivities (eeanti up to 98%). Inductively coupled plasma optical emission spectrometer (ICP-OES) measurements of the supernatant and hot leaching test suggest the heterogeneous nature of the catalyst. Macrosubstrate tests verify that the reaction occurs inside the pores of the MOF. The heterogeneous catalyst can maintain structural stability and catalytic activity within three cycles. Graphic Abstract: Versatile Pd(II) and l-proline were metalated and decorated, respectively, into stable UiO-67 to construct bifunctional and heterogeneous multivariate MOF catalyst, which displayed efficient and recyclable catalytic activity in sequential Suzuki Coupling/asymmetric Aldol reactions.[Figure not available: see fulltext.]
Cheng, Lin,Cao, Liumei,Ren, Hao,Guo, Qiaoqiao,Deng, Huifang,Li, Yiming
p. 1160 - 1169
(2022)
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New bisbenzimidazolin-2-ylidene salts as N-heterocyclic dicarbene precursors: Synthesis, characterization, and involvement in palladium-catalyzed Suzuki reactions
A new series of bis-N-heterocyclic carbene precursors, LHX (3a-d), have been synthesized and characterized by appropriate spectroscopic techniques and microanalyses. In situ prepared Pd(OAc)2/bis-N-heterocyclic carbene precursors catalysts have catalyzed unactivated aryl chlorides on the Suzuki cross-coupling reaction under mild reaction conditions in aqueous media.
Yasar, Sedat,Cekirdek, Suzan,Oezdemir, Ismail
p. 157 - 162
(2014)
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Bipyridyl palladium embedded porous organic polymer as highly efficient and reusable heterogeneous catalyst for Suzuki-Miyaura coupling reaction
Two robust porous organic polymers embedded with bipyridyl ligand (Bpy-POP) were obtained via a bottom-up strategy. After a simple post-treatment, a Pd(ii)-containing POP (Bpy-Pd-POP) was used as highly efficient and reusable heterogeneous catalyst for the Suzuki-Miyaura coupling reaction. It could be reused at least 15 times without significant loss of the catalytic activity (97-99% yield).
Wang, Chang-An,Han, Yin-Feng,Li, Yan-Wei,Nie, Kun,Cheng, Xue-Li,Zhang, Jian-Ping
p. 34866 - 34871
(2016)
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Two metal-organic frameworks based on a double azolium derivative: Post-modification and catalytic activity
A new bifunctional N-heterocyclic carbene (NHC) precursor was used to construct two metal-organic frameworks, which can anchor palladium(ii) sites by post-modification, presenting remarkable framework dependent catalytic activities.
Kong, Guo-Qiang,Xu, Xuan,Zou, Chao,Wu, Chuan-De
p. 11005 - 11007
(2011)
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Syntheses, structural aspects, solution behavior, and catalytic utility of cyclopalladated N,N′,N″-triarylguanidines [κ2(C,N))Pd(Pyrazole)2X] (X = Br, OC(O)CF3, and PF6) in Suzuki-Miyaura coupling reactions of a
The reactions of six-membered cyclopalladated N,N′,N″-triarylguanidines [κ2(C,N)Pd(μ-X)]2 (3-7) with 2 equiv of pyrazole (pzH) and 3,5-dimethylpyrazole (3,5-dmpzH) in CH2Cl2 at RT for 24 h afforded a new class o
Agarwal, Pallavi,Thirupathi, Natesan,Nethaji, Munirathinam
p. 3112 - 3123
(2016)
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Suzuki coupling reactions in pure water catalyzed by supported palladium -relevance of the surface polarity of the support
Heterogeneous (supported) palladium catalysts like palladium on carbon and a variety of metal oxides have been shown to be highly active for Suzuki coupling reactions in neat water under mild reaction conditions (T=65°C). It has been demonstrated for the first time that hydrophobic effects of the catalyst surface play an important role for the catalyst activity in water. Catalysts possessing hydrophobic surfaces (e.g., palladium on carbon) show higher activity for Suzuki coupling reactions in water than their hydrophilic counterparts (palladium on metal oxides). Tuning of the surface polarity of metal oxide supports (by silylation) results in higher activity under these conditions. Stronger alkaline conditions (three-fold excess of base) compensate the effect of hydrophobic supports and result in high activity of the catalysts also with hydrophilic supports. The addition of tetrabutylammonium bromide to generate, activate and stabilize the catalytic species (dissolved palladium complexes) is necessary for the conversion of more demanding substrates. The reaction is considered to be homogeneous taking place near the catalyst surface inside a droplet or layer of the reactant. Copyright
Soomro, Saeeda S.,Roehlich, Christoph,Koehler, Klaus
p. 767 - 775
(2011)
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Palladium nanoparticles encapsulated in MIL-101-NH2 catalyzed one-pot reaction of Suzuki-Knoevenagel reaction
Bifunctional Cr-MOF catalysts containing palladium nanoparticles (NPs) have been prepared. Combining the high activity of Pd NPs and base sites in MIL-101-NH2, the catalysts (Pd?MIL-101-NH2) exhibited distinct catalytic activity in a
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On the photophysical and photochemical behavior of fenbufen: A study in homogeneous media and micellar environments
The photochemistry of fenbufen, γ-oxo-[1,1′-biphenyl]-4-butanoic acid (FB), has been investigated in homogeneous solutions and in micellar environments. The photochemical and photophysical properties of the drug are mediated by its lowest excited triplet states. The presence of a low-lying π,π* triplet is responsible for the inefficient Norrish Type I photocleavage, whereas an upper n,π* triplet promotes a large intersystem crossing yield. FB interacts with both anionic and cationic micelles. The different binding mode of the drug with the microheterogeneous environments can significantly change its photoreactivity. These changes are rationalized on the basis of "micellar cage effects".
Sortino,Martinez,Marconi
p. 975 - 980
(2001)
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PdCuCeO-TPAB: A new catalytic system for quasi-heterogeneous Suzuki-Miyaura cross-coupling reactions under ligand-free conditions in water
In this contribution, we report a simple and clean method for preparation of a single-phase Pd0.04Cu0.04Ce0.92O2-δ (PdCuCeO) solid-solution oxide and its application in quasi-heterogeneous Suzuki-Miyaura cross-coupling reactions. The catalyst was characterised fully and all the characterisation techniques strongly suggest that the Pd2+ and Cu2+ ions were successfully incorporated into the lattice of ceria. The as-prepared PdCuCeO solid-solution oxide was tested on Suzuki-Miyaura cross-coupling reactions under ligand free conditions using water as a sole solvent and tetrapropylammonium bromide (TPAB) as a phase transfer catalyst. It was discovered that TPAB acts as scavenger of Pd and the resulting material (Pd/TPAB) is able to catalyse the Suzuki-Miyaura coupling reaction. The Suzuki-Miyaura coupling of aryl iodides, bromides as well as activated aryl chlorides was efficiently performed by this PdCuCeO-TPAB catalytic system. The PdCuCeO-TPAB catalytic system also displayed good functional group tolerance and good to excellent isolated yields were obtained. Catalyst leaching and recyclability studies revealed that PdCuCeO acts as a Pd reservoir and that the reactions are essentially quasi-heterogeneous occurring over the recoverable Pd/TPAB aggregates. Only a negligible amount of palladium (0.1 ppm) was detected by ICP-OES in the product solution.
Mpungose, Philani P.,Sehloko, Neo I.,Maguire, Glenn E. M.,Friedrich, Holger B.
p. 13560 - 13566
(2017)
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Palladium-decorated o-phenylenediamine-functionalized Fe3O4/SiO2 magnetic nanoparticles: A promising solid-state catalytic system used for Suzuki–Miyaura coupling reactions
Palladium-supported o-phenylenediamine-functionalized Fe3O4 magnetic nanoparticles are presented. A convenient synthetic route for the nanocatalyst and also its application in Suzuki–Miyaura coupling of various aryl halides with phenylboronic acids are described. A high reaction yield (98%) was been obtained in a short reaction time (10 min) through use of this highly efficient nanocatalyst. From a mechanistic aspect, firstly, effective electronic interactions between heteroatoms such as oxygen and Pd(II) provide a suitable condition for covalent bonding by the ingredients in the Suzuki–Miyaura coupling reaction. Secondly, Pd(II) is converted to Pd(0) by use of sodium borohydride in the presence of triphenylphosphine in basic conditions, and then it plays a main role in the catalytic process. However, the most distinguished properties of this catalytic system are the ease of catalyst separation and great reusability. The palladium-supported o-phenylenediamine-functionalized Fe3O4 nanoparticles can be easily recovered by use of an external magnet and can reused at least ten times with no significant decline in catalytic activity. This novel system was structurally characterized by various analytical methods, and the results obtained are well interpreted in the context.
Maleki, Ali,Taheri-Ledari, Reza,Ghalavand, Reza,Firouzi-Haji, Razieh
(2020)
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Suzuki-Miyaura reaction of unactivated aryl chlorides using benzimidazol-2-ylidene ligands
Four functionalized bis(benzimidazolium) salts (2a-d) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle, and environmentally bengin process for palladium-mediated Suzuki cross-coupling was developed. The in situ prepared three-component system Pd(OAc)2/bis(benzimidazolium) bromides (2a-d) and Cs2CO3 catalyzes quantitatively the Suzuki cross-coupling of deactivated aryl chloride in aqueous media.
Oezdemir, Ismail,Goek, Yetkin,Guerbuez, Nevin,Cetinkaya, Engin,Cetinkaya, Bekir
p. 4135 - 4144
(2004)
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"Click" dendrimers as efficient nanoreactors in aqueous solvent: Pd nanoparticle stabilization for sub-ppm Pd catalysis of Suzuki-Miyaura reactions of aryl bromides
Palladium nanoparticles (PdNPs) with a size of 1.4 nm are stabilized by dendritic nanoreactors containing 1,2,3-triazole ligands with hydrophilic triethylene glycol (TEG) termini. These PdNPs are stable for months under air and are extremely active for the Suzuki-Miyaura reactions of aryl bromides down to sub-ppm levels.
Deraedt, Christophe,Salmon, Lionel,Etienne, Laetitia,Ruiz, Jaime,Astruc, Didier
p. 8169 - 8171
(2013)
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Generation of Polyphenylene Radical Cations and Their Cosensitization Ability in the 9,10-Dicyanoanthracene-Sensitized Photochemical Chain Reactions of 1,2-Bis(4-methoxyphenyl)cyclopropane
Cosensitization effects of polyphenylene compounds (PP) such as biphenyl (BP), terphenyls (o-, m-, p-TP), and phenanthrene (Phen) in photoinduced electron-transfer reactions were examined. The 9,10-dicyanoanthracene (DCA)-sensitized cis-trans photoisomerization of 1,2-bis(4-methoxyphenyl)-cyclopropane (CP), which proceeds in a chain reaction via free radical cation of CP (CP.+) as a chain carrier, was accelerated by adding PP, particularly by TP. A similar accelerating effect was observed in the DCA-sensitized photooxygenation of CP as another example. BP and TP were more stable under the oxygenation condition than phenanthrene and naphthalene, which also accelerate the photooxygenation CP. CP.+ is generated by the direct electron transfer from CP to the excited singlet state of DCA (1DCA*) and also by the secondary electron transfer from CP to PP.+, which is generated by the primary electron transfer from PP to 1DCA*. The laser flash photolysis study revealed that the quantum yield for the formation of free CP.+ in the direct electron transfer from CP to 1DCA* (ΦCP.+ ≈ 0.1) was smaller than that in the presence of PP. This is due to the high yield of free PP.+ generation by the primary electron transfer and the efficient secondary electron transfer from CP to PP.+. The secondary electron transfers were found to take place in nearly diffusion-controlled rates (0.9-1.5 × 1010 M-1 s-1). The high yield of PP.+ as free radical ions does not seem to be the sole factor of the cosensitization of PP for the DCA-sensitized photoreactions of CP. The ratio of the quantum yields of the photoreactions to that of the initial CP.+ formation (turnover) also increased by the addition of PP from 3 (isomerization) and 15 (oxygenation) to 32-90 for both reactions. The second-order rate constant for the decay of CP.+ in aerated acetonitrile was decreased by a factor of 0.5-0.8 by the addition of PP. We concluded that the cosensitization effect in the photoreaction involves a π-complex formation between CP.+ and PP assisting the chain reaction as well as initial CP.+ formation.
Tamai, Toshiyuki,Ichinose, Nobuyuki,Tanaka, Tomoko,Sasuga, Tsuneo,Hashida, Isao,Mizuno, Kazuhiko
p. 3204 - 3212
(1998)
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Palladium-catalyzed suzuki reaction using 1,3-Dialkylbenzimidazol-2-ylidene ligands in aqueous media
From readily available starting compounds, six functionalized 1,3-dialkylbenzimidazolium salts (2a-c and 4a-c) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle, and environmentally benign process for palladium-mediated Suzuki cross-coupling was developed. The in situ prepared three-component systems Pd(OAc)2/1,3-dialkylbenzimidazolium chlorides and Cs2CO3 catalyze quantitatively the Suzuki cross-coupling of deactivated aryl chlorides.
Oezdemir, Ismail,Goek, Yetkin,Guerbuez, Nevin,Cetinkaya, Engin,Cetinkaya, Bekir
p. 419 - 423
(2004)
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Multifunctional redox polymers: Electrochrome, polyelectrolyte, sensor, electrode modifier, nanoparticle stabilizer, and catalyst template
Simple "click" polycondensation metallopolymers of redox-robust bis(ethynyl)biferrocene (biFc) and di(azido) poly(ethylene glycol) (PEG400 and PEG1000) were designed for multiple functions including improvement of water solubility and biocompatibility, the introduction of mixed valency and sensing capabilities, and as nanoparticle stabilizers for catalysis.
Deraedt, Christophe,Rapakousiou, Amalia,Wang, Yanlan,Salmon, Lionel,Bousquet, Melanie,Astruc, Didier
p. 8445 - 8449
(2014)
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Base-Controlled One-Pot Chemoselective Suzuki-Miyaura Reactions for the Synthesis of Unsymmetrical Terphenyls
We report a chemoselective Suzuki-Miyaura reaction protocol of using bromophenyl fluorosulfonate as building block for the preparation of unsymmetrical terphenyls. The chemoselective cross-coupling of bromophenyl fluorosulfonate and arylboronic acids can be achieved by controlling base species without using any ligands. Under this methodology, various of m - and p -unsymmetrical terphenyls were obtained in moderate to good yields.
Feng, Fangfang,Hu, Qinghong,Li, Xinmin,Ren, Changyue,Teng, Yong,Yuan, Zeli
p. 2131 - 2135
(2019)
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Polymeric microsphere-loaded palladium-iminodiacetic acid complex as an efficient and easily recycled catalyst for Suzuki reaction in ionic liquid
Core-crosslinked shelled-core microspheres of poly(styrene-co-methyl acrylic acid) (PS-co-PMAA), with cores rich in PS and the shell rich in PMAA, were synthesized by one-stage soap-free emulsion polymerization. A palladium (Pd)-iminodiacetic acid (IDA) complex catalyst is loaded on the shell of the PS-co-PMAA microsphere, which results in the advantage of high dispersion degree and, therefore, high activity. The resultant polymeric microspheres catalyst systems are then applied to catalyze the Suzuki reaction of aryl halides with phenylboronic acid in an ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]). Our catalyst systems are proved to be efficient and active for both aryl bromides and aryl iodides. Compared to traditional Pd(Ph3)4 catalyst, the PS-co-PMAA-IDA-Pd catalyst used here affords higher yield of Suzuki reaction at even lower catalyst concentration. In addition, our polymeric-microsphere based catalytic system can be easily recycled at least four times with high activity in ionic [bmim][BF4] liquid.
Zhang, Jianzheng,Chen, Jingshuai,Zhang, Qiuyu,Wang, Rumin,Wu, Songhua
p. 2503 - 2514
(2019)
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Facile, mild and selective silica sulfuric acid catalyzed oxidation of benzylalcohols to benzaldehyde derivatives by potassium peroxodisulfate
An efficient, facile, and mild oxidation of a variety of primary benzylic alcohols to the corresponding aldehydes with potassium peroxodisulfate in the presence of a catalytic amount of sodium chloride and silica sulfuric acid (SSA) in acetonitrile as solvent is reported. It is a renowned fact that potassium peroxodisulfate acts as a powerful oxidizing agent and the control of conditions is difficult. For this purpose, SSA as a mild, efficient and reusable solid acid catalyst was used to afford the carbonyl compounds in excellent yields and short time. The structure of all of the resulting products was confirmed by FT-IR spectroscopy.
Badri, Rashid,Alizadeh-haddad, Alireza,Adlu, Maryam,Mohammadi, Mohammad Kazem
p. 131 - 136
(2013)
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Knowles
p. 896
(1921)
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Highly uniform Pd nanoparticles supported on g-C3N4 for efficiently catalytic suzuki-miyaura reactions
Pd nanoparticles were supported on the surface of g-C3N4 by a facile method assisted by ultrasonication. The Pd/g-C3N4 catalyst was characterized by N2-adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The XRD and TEM analyses reveal that the Pd nanoparticles are evenly distributed on the surface of g-C3N4 with an average size of 4 nm. The XPS results indicate that the Pd interacts with the N of g-C3N4. The supported catalyst shows high efficiencies in Suzuki- Miyaura reactions with up to 99% isolated yield under mild reaction conditions. The catalyst can be easily recycled at least 3 times without any loss of activity and selectivity. The excellent performance of the catalyst in activity and reusability may be attributed to the strong interaction between g-C3N4 and Pd nanoparticles, and the robust nature of the CN framework, respectively.
Su, Xiangyang,Vinu, Ajayan,Aldeyab, Salem S.,Zhong, Lin
p. 1388 - 1395
(2015)
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New strategy by a two-component heterogeneous catalytic system composed of Pd–PVP–Fe and heteropoly acid as co-catalyst for Suzuki coupling reaction
We have developed a simple and efficient catalytic protocol composed of hollow palladium-poly(N-vinylpyrrolidone)-nano zero valent iron and H5PMo10V2O40 (Mo10V2) supported on Fe2O3@SiO2 core–shell nano particles, as reusable catalytic system for Suzuki coupling reaction under ligand- and base-free conditions. These reusable solid catalysts exhibited excellent activity and the methodology is applicable to diverse substrates providing good-to-excellent yields of desired products. This method has advantages of high yields, low reaction times, elimination of ligand and base, heterogeneous catalysts, and simple methodology. In order to study the role of Fe@Si–Mo10V2 in the Suzuki coupling reaction, electron transfer property of Fe@Si–Mo10V2 and Pd–PVP–Fe by means of cyclic voltammetry measurements were investigated. Moreover, this catalytic system could be recovered in a facile manner from the reaction mixture and recycled several times without any significant loss in activity. In this study, the heterogeneity of both component of our catalytic system was investigated and the content of palladium (Pd) and Mo10V2 into filtrates was evaluated quantitatively by inductively coupled plasma atomic emission spectroscopy (ICP-AES). According to the obtained results from the ICP-AES measurements, the small amount of Pd and Mo10V2 leach have been obtained.
Rafiee, Ezzat,Kahrizi, Masoud,Joshaghani, Mohammad,Ghaderi-Sheikhi Abadi, Parvaneh
p. 5573 - 5585
(2016)
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Palladium supported on aminopropyl-functionalized polymethylsiloxane microspheres: Simple and effective catalyst for the Suzuki-Miyaura C-C coupling
Abstract A palladium catalyst, obtained in the reaction of PdCl2(MeCN)2 with microspheric aminopropyl polymethylsiloxane, was used in the Suzuki-Miyaura cross-coupling of various aryl bromides with phenylboronic acids. Catalytic reactions, performed at 80°C in a 2-propanol/water mixture, led to high yields of non-symmetric biphenyls. In recycling experiments, excellent results (up to 100%) were obtained in ten subsequent runs. Efficient separation of the catalyst from organic products was achieved by simple filtration due to the properties of microspheres.
Zawartka, Wojciech,P?piech, Piotr,Cypryk, Marek,Trzeciak, Anna M.
p. 230 - 235
(2015)
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Facilitating a high-performance photocatalyst for Suzuki reaction: Palladium nanoparticles immobilized on reduced graphene oxide-doped graphitic carbon nitride
We prepared a non-covalently coupled hybrid of reduced graphene oxide (rGO)-doped graphitic carbon nitride (g-C3N4) by freezing-assisted assembly and calcination. Fourier transform infrared, Raman and X-ray photoelectron spectroscopies and transmission electron microscopy confirmed that rGO was incorporated into the bulk g-C3N4, which was an ideal support for loading Pd nanoparticles. The Pd nanoparticles with an average size of 4.57?nm were uniformly dispersed on the rGO-doped g-C3N4 surface. The layered structure provided large contact area of g-C3N4 with rGO, further accelerating the electron transfer rate and inhibiting electron–hole recombination. Consequently, compared with Pd/rGO/g-C3N4 and Pd/g-C3N4, the Pd/rGO-doped g-C3N4 showed a prominent catalytic activity for visible-light-driven photocatalytic Suzuki–Miyaura coupling at ambient temperature. The Pd/rGO-doped g-C3N4 exhibited very high stability after six consecutive cycles with minimal loss of catalytic activity.
Zhao, Xiaohua,Xie, Jiateng,Liu, Xin,Liu, Xiang
(2019)
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Efficient photocatalytic Suzuki cross-coupling reactions on Au-Pd alloy nanoparticles under visible light irradiation
We report herein highly efficient photocatalysts comprising supported nanoparticles (NPs) of gold (Au) and palladium (Pd) alloys, which utilize visible light to catalyse the Suzuki cross-coupling reactions at ambient temperature. The alloy NPs strongly absorb visible light, energizing the conduction electrons of NPs which produce highly energetic electrons at the surface sites. The surface of the energized NPs activates the substrates and these particles exhibit good activity on a range of typical Suzuki reaction combinations. The photocatalytic efficiencies strongly depend on the Au:Pd ratio of the alloy NPs, irradiation light intensity and wavelength. The results show that the alloy nanoparticles efficiently couple thermal and photonic energy sources to drive Suzuki reactions. Results of the density functional theory (DFT) calculations indicate that transfer of the light-excited electrons from the nanoparticle surface to the reactant molecules adsorbed on the nanoparticle surface activates the reactants. The knowledge acquired in this study may inspire further studies of new efficient photocatalysts and a wide range of organic syntheses driven by sunlight. the Partner Organisations 2014.
Xiao, Qi,Sarina, Sarina,Jaatinen, Esa,Jia, Jianfeng,Arnold, Dennis P.,Liu, Hongwei,Zhu, Huaiyong
p. 4272 - 4285
(2014)
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Nano NiFe2O4 supported phenanthroline Cu(II) complex as a retrievable catalyst for selective and environmentally friendly oxidation of benzylic alcohols
A new magnetically recoverable catalyst consisting of phenanthroline Cu(II) complex supported on nickel ferrite nanoparticles was prepared. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission and scanning electron microscopes, thermogravimetry, energy dispersive X-ray spectroscopy, vibrating sample magnetometry and inductively coupled plasma. Supported copper complex used for solvent free oxidation of 1- phenyl ethanol as a model. Influence of the reaction parameters (kind of oxidant, amount of the catalyst, reaction time, solvent and reaction temperature) were studied. Because of the immobilized complex has been shown to be an efficient heterogeneous catalyst for the selective oxidation of 1-phenyl ethanol to acetophenone (94% yield) by hydrogen peroxide so this green approach extended to other benzylic alcohols. The catalyst had been reused 10 times with no significant loss of catalytic activity. SEM, EDX, XRD, and ICP analysis of reused catalyst indicated that the catalyst was stable after the reaction.
Mehrjoyan, Forouzan,Afshari, Mozhgan
(2021)
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Lanthanide and asymmetric catalyzed syntheses of sterically hindered 4-isoxazolyl-1,4-dihydropyridines and 4-isoxazolyl-quinolones
The Ytterbium (III) triflate catalyzed Hantzsch synthesis allows for the preparation of sterically hindered 4-isoxazolyl-1,4-dihydropyridines in moderate to good yields. Asymmetric organocatalysis with (R)-4-Oxo-2,6-bis-(2,4,6-triisopropyl-phenyl)-3,5-dioxa-4l5-phospha-cyclohepta[2,1-a;3,4-a']dinaphthalen-4-ol (R-TRIP) produces moderate yields of chiral 4-isoxazolyl-quinolones with high enantioselectivity.
Steiger, Scott A.,Li, Chun,Campana, Charles F.,Natale, Nicholas R.
p. 423 - 425
(2016)
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Ultrafine and Highly Dispersed Pd/SiO2 for Suzuki?Miyaura Cross-coupling Reactions
Abstract: Construction of heterogeneous Pd/SiO2 catalyst via the pollution-free strategy marked strong electrostatic adsorption has been reported for the application to Suzuki–Miyaura cross-coupling reactions. The exposed negatively charged oxygen groups, which were converted from the hydroxyl groups on the surface of silica under the alkaline atmosphere, could effectively anchor palladium species to form ultrafine Pd nanoparticles (Pd NPs) with an average particle size of 1.3?nm and high dispersion (43%). Pd/SiO2 catalyst was endowed with the excellent catalytic performance which was that the yield of the Suzuki–Miyaura reaction between bromobenzene and phenylboronic acid at 40?°C was > 99% for 30?min and the TOF was ~ 80,000?h?1. The catalyst could be easily recovered and recycled by facile procedure without a significant decrease in catalytic activity, which was able to maintain the 90% yield after repeated for 8 times. In addition, a continuous flow reaction device was designed using the Pd/SiO2 catalyst to effectively improve the production efficiency of biphenyl. Graphic Abstract: Pd/SiO2 catalyst constructed with the strategy of strong electrostatic adsorption (SEA) possesses uniformly dispersed and highly exposed Pd sites which can be easily transformed into electron-deficient Pdδ+ and strengthened stability for itself due to its strong interaction with the front surface of the carrier, and has been endowed the outstanding catalytic performance for Suzuki?Miyaura cross-coupling reaction. [Figure not available: see fulltext.]
Fan, Xizheng,Yang, Jingyi,Pang, Qingqing,Liu, Zhongyi,Zhang, Panke,Yang, Jing-He
p. 2291 - 2301
(2021)
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Construction of heterometallic M2Pd3 supramolecular cages via a metalloligand strategy as heterogeneous catalyst for Suzuki–Miyaura coupling reaction
On the basis of hard soft acid base theory, two neutral heterometallic M2Pd3 supramolecular cages, [Al2Pd3(L)6Cl6] (1) and [Fe2Pd3(L)6Cl6] (2) (where HL is 1-(4-(1H-imidazol-1-yl)phenyl)butane-1,3-dione), have been constructed by using the tripodal M(L)3 as metalloligands in combination with PdCl2 or Pd(MeCN)2Cl2. The supramolecular cage can be described as a trigonal bipyramid with two M3+ ions occupying at the two axial sites in ΔΔ or ΛΛ configurations and three Pd2+ ions sitting in the three equatorial positions with square planar geometry in trans configuration. The supramolecular cages exhibit high catalytic activity for the Suzuki–Miyaura coupling with arylbromide or arylchrolide and phenylboronic acid in biorenewable solvent glycerol under mild conditions. Moreover, the catalyst can be readily recycled and reused at least five times without loss of catalytic activity. The high catalytic performance may be attributed to the distinct properties of the cage structure with uniformly distributive and well-defined Pd active centres on the cage surfaces. The high stability in the cage structure also prevents Pd leaching out and agglomeration.
Wu, Xi-Ren,Yao, Su-Yang,Wei, Lian-Qiang,Li, Li-Ping,Ye, Bao-Hui
p. 605 - 611
(2018)
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Synthesis and catalytic application of cyclopentadienyl nickel(II) N-heterocyclic carbene complexes
A series of ester-functionalized benzimidazolium salts 2a–c were prepared by quaternization of 1-{(ethoxycarbonyl)methyl}benzimidazole (1) with 3,5-dimethylbenzyl bromide, 2,5-dimethylbenzyl chloride and 3-methoxybenzyl chloride, respectively. Refluxing 2a–c with nickelocene in THF yielded the neutral cyclopentadienyl NHC nickel(II) complexes 3a–c. Their structures were defined by NMR, IR and elemental analysis techniques. Molecular weights of 3a–c were affirmed by MALDI-TOF mass spectrometry. Catalytic tests of 3a–c were performed in Kumada coupling of some aryl chlorides with phenylmagnesium bromide at 25 °C.
Demir Atli, Deniz
p. 1530 - 1537
(2020)
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Pd-N-Heterocyclic carbene catalysed Suzuki-Miyaura coupling reactions in aqueous medium
A new series of methyl substituted imidazole-based N-heterocyclic carbene (NHC) palladium complexes (PdCl2(L1)NHC(L1 =pyridine) is reported. Structural definitions of Pd-PEPPSI complexes were determined by NMR spectroscopy, elemental analysis and LC-MS sp
Karaca, Emine ?zge,Akko?, Mitat,Yasar, Sedat,?zdemir, Ismail
p. 230 - 239
(2018)
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Resin-trapped gold nanoparticles: An efficient catalyst for reduction of nitro compounds and Suzuki-Miyaura coupling
Gold in nanoparticle form shows good catalytic activity in contrast to bulk form and is finding applications in a variety of organic reactions. The present investigation describes direct deposition of gold nanoparticles onto commercially available resin by sorption reduction method. Uniformly dispersed nanoparticles of 3-8 nm dimensions were characterized by UV-visible spectroscopy, XRD, SEM and TEM, etc. The AuNPs were found to be remarkably stable and active catalysts for the selective reduction of nitro group under mild reaction conditions and microwave-assisted ligand-free Suzuki-Miyaura cross-coupling reaction between aryl halides and phenylboronic acid. Calculated rate constant (2.5 × 10-2 s-1) for the reduction of 4-nitrophenol is among the best reported in the literature. The versatility of both the protocols is demonstrated by taking a number of substrates.
Shah, Dipen,Kaur, Harjinder
p. 70 - 76
(2014)
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Optimized dispersion and stability of hybrid Fe3O4/Pd catalysts in water for Suzuki coupling reactions: Impact of organic capping agents
Pd nanoparticles were easily immobilized on Fe3O4 microspheres without any treatment such as functionalization with organic groups. The Fe3O4 microspheres were synthesized by using different capping agents, and the effect of the capping agents on the dispersion stability and catalytic activity of the Fe3O4/Pd composite for Suzuki coupling reactions in water were evaluated. The catalytic activity varied depending on the dispersion stability of Fe3O 4/Pd catalysts in water. The Pd nanoparticles immobilized onto Fe3O4 microspheres capped with trisodium citrate showed strong dispersion stability in water over the reaction duration of seven days (at pH 7), high catalytic activity, and recyclability under mild conditions. Lemon boost: Immobilized Pd nanoparticles onto Fe3O4 microspheres synthesized with different capping agents exhibit different catalytic activities for Suzuki coupling reactions depending on the dispersion stability in water. Capping by trisodium citrate leads to the highest yield and recyclability with strong and long-term dispersion stability in water. Cit= citrate, PEG= poly- (ethylene glycol), PVP=poly(vinylpyrrolidone).
Woo, Hyunje,Lee, Kyoungho,Park, Kang Hyun
p. 1635 - 1640
(2014)
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1,4,5,6-tetrahydropyrimidinium halides ligands for Suzuki-Miyaura cross-coupling of unactivated aryl chlorides
Four functionalized bis(1,4,5,6-tetrahyropyrimidinium) salts (2a-d) have been prepared and characterized by conventional spectroscopic methods and elemental analyses. A highly effective, easy to handle and environmentally benign process for palladium mediated Suzuki cross-coupling was developed. The in situ prepared three component system Pd(OAc)2 / bis(1,4,5,6-tetrahyropyrimidinium) bromides (2a-d) and Cs2CO 3 catalyses quantitatively the Suzuki cross-coupling of deactivated aryl chloride.
Alici, Buelent,Oezdemir, Ismail,Guerbuez, Nevin,Cetinkaya, Engin,Cetinkaya, Bekir
p. 1439 - 1445
(2005)
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Palladium catalyzed Suzuki coupling reactions using cobalt-containing bulky phosphine ligands
Three bulky mono-dentate alkyne-bridged dicobalt-phosphine complexes [(μ-PPh2CH2PPh2)Co2(CO) 4](μ,η-PhC≡CPPh2) 4a, [(μ-PPh 2CH2PPh2)Co2(CO)4
Hong, Fung-E.,Ho, Yi-Jung,Chang, Yu-Chang,Lai, Yi-Chun
p. 2639 - 2645
(2004)
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Catalytic comparison of Pd-C60 complex and its non-fullerene form bearing phosphorus ylide in C–C coupling reactions
The new fullerene-based Pd complex [(η2-C60) Pd(Y)2] (1) and its non-fullerene form [(Y)PdCl2] (2) bearing unsymmetrical phosphorus ylide [Ph2P(CH2)2PPh2 = C(H)C(O)Cs
Fatahi, Somayeh,Javad Sabounchei, Seyyed,Panahimehr, Mohammad,William Gable, Robert,Yousefi, Abed
(2022/01/08)

A comparative study of catalytic activity on iron-based carbon nanostructured catalysts with Pd loading: Using the Box–Behnken design (BBD) method in the Suzuki–Miyaura coupling
Highly dispersed palladium nanoparticles immobilized on surface-modified Fe3O4 NPs and magnetic carbon nanostructures (CNSs; carbon nanotubes/graphene oxide) were synthesized and applied as a recyclable and reusable nanocatalyst to achieve palladium (II)-catalyzed Suzuki–Miyaura reaction of arylboronic acid with aryl bromides. Carbon nanostructures with immobilized hydantoin (PH)-Pd complex display excellent stability, including a high performance at low catalyst loading. Magnetic separation prevents catalyst centrifuge or filtration and also contributes to practical techniques for recovery. Next, a response surface method based on a three-level Box–Behnken design was used, which involved three factors: catalyst loading, reaction time, and solvent. The Box–Behnken method was advantageous to parameters optimization for obtaining a yield, with high efficiency and accuracy. As a result of catalytic tests, the TONs and TOFs were calculated from all coupling reactions. The prepared nano-magnetic catalysts, after the catalysis reaction, can be easily recovered through the magnetic field. Evaluated catalytic performance indicates that these types of catalysts can function as effective recyclable catalysts at least five times without losing the initial level of catalytic activity.
Moniriyan, Faezeh,Sabounchei, Seyyed Javad
(2021/09/13)

Synthesis of new adamantyl-imine palladium(II) complexes and their application in Mizoroki-Heck and Suzuki-Miyaura C[sbnd]C cross-coupling reactions
Improving carbon–carbon cross-coupling reactions is an ongoing process and finding the most versatile and stable catalyst precursors has been of great interest. Ligand design has been proven to be important since it is responsible for providing electron density and steric saturation around the metal centre, thus contributing towards the stereo-electronic properties. The adamantyl moiety has been used to generate highly bulky and electron-rich ligands for application in palladium-catalysed cross-coupling reactions. Accordingly, we have prepared some Schiff-base adamantyl ligands (L1-L3) and complexed them with [PdCl2(MeCN)2] to afford the (pre)catalysts C1-C3, which were successfully applied in Mizoroki-Heck and Suzuki-Miyaura carbon–carbon cross-coupling reactions. The cross-coupling reaction products were obtained in good yields using 0.5 mol % Pd catalyst loading. C2 and C3 showed remarkable activity in the Mizoroki-Heck coupling reactions involving substrates with substituents on the olefin and aryl halide (including 4-Cl, 4-CH3, -CO2Me and -CO2Et). We also, observed that the Suzuki-Miyaura cross-coupling system was active towards challenging activated and deactivated aryl chlorides, with to up 70% conversions recorded. The mercury poisoning tests conducted revealed that the catalysts act as homogenous molecular active species in the Mizoroki-Heck reactions and act as both homogenous and heterogeneous catalysts in the Suzuki-Miyaura cross-coupling reactions.
Makhubela, Banothile C. E.,Matsheku, Asanda C.,Maumela, Munaka C.
(2021/06/18)

A tryptophan-based copper(ii) coordination polymer: catalytic activity towards Suzuki-Miyaura cross-coupling reactions
Herein, we report the synthesis and crystal structure determination of a new Cu(ii) coordination polymer (CP) with the formula [Cu(l-tryp)(azpy)1/2(H2O)(NO3)]∝ (CP1), which exhibits an unusual tryptophan coordination mode with copper(ii) via carboxylate monodentate binding as well as chelation via Namino and Ocarbonyl groups. CP1 was prepared using the ligand l-tryptophan (l-tryp) and the co-ligand 4,4′-azopyridine (azpy), adapting the mixed-ligand approach and a solvothermal protocol. Single crystal X-ray structural analysis revealed that in CP1, Cu(ii) sites show a distorted octahedral geometry, wherein the ligand l-tryp is coordinated through the carboxylate and amine groups, whereas the co-ligand azpy is coordinated to Cu(ii) ions through the Npyridyl atom and thus maintains a distorted octahedral geometry around the Cu(ii) ions. FT-IR and EPR spectra were also recorded to corroborate the structural analysis. Finally, CP1 was employed as a heterogeneous catalyst for the Suzuki cross-coupling reaction and afforded ～98% yield under normal reaction conditions. This journal is
Bhasin, K. K.,Husain, Ahmad,Kumar, Girijesh,Kumar, Rakesh,Nar, Kuldeep Kaur,Rani, Pooja,Singh, Amit Pratap
p. 7855 - 7864
(2021/12/02)

Fe3O4-SAHPG-Pd0 nanoparticles: A ligand-free and low Pd loading quasiheterogeneous catalyst active for mild Suzuki–Miyaura coupling and C-H activation of pyrimidine cores
This paper reports a green magnetic quasiheterogeneous efficient palladium catalyst in which Pd0 nanoparticles have been immobilized in self-assembled hyperbranched polyglycidole (SAHPG)-coated magnetic Fe3O4 nanoparticles (Fe3O4-SAHPG-Pd0). This catalyst has been used for effective ligandless Pd catalyzed Suzuki–Miyaura coupling reactions of different aryl halides with substituted boronic acids at room temperature and in aqueous media. Herein, SAHPG is used as support; it also acts as a reducing agent and stabilizer to promote the transformation of PdII to Pd0 nanoparticles. Also, this environmental friendly quasiheterogeneous catalyst is employed for the first time in the synthesis of new pyrimido[4,5-b]indoles via oxidative addition/C-H activation reactions on the pyrimidine rings, which were obtained with higher yield and faster than when Pd(OAc)2 was used as the catalyst. Interestingly, the above-mentioned catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device and recycled several times with no significant decrease in the catalytic activity.
Azizollahi, Hamid,Eshghi, Hossein,García-López, José-Antonio
(2020/09/17)

Suzuki coupling reactions catalyzed by Schiff base supported palladium complexes bearing the vitamin B6 cofactor
Novel Schiff bases were synthesized by condensing aromatic amines with pyridoxal-5’-phosphate and characterized by using FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The resulting Schiff bases were utilized as bidentate ligands, coordinating via imine nitrogen and phenolate oxygen atoms, to stabilize palladium ions. Aryl substituents on imine nitrogen allowed for fine tuning of the stereoelectronic properties of the Schiff bases. The catalytic activity of the selected palladium complexes was investigated in the Suzuki cross-coupling reaction of a series of aryl halides with boronic acids in H2O/EtOH (1:1). Out of four complexes investigated in the cross-coupling reactions, Pd(L8)2, bearing a methoxy substituent on aryl imine, showed the highest activity at low catalyst loading. The scope of the reaction was also investigated with 26 samples.
Neshat, Abdollah,Gholinejad, Mohammad,?zcan, Hafize,Khosravi, Faezeh,Mobarakeh, Ali Mousavizadeh,Zaim, ?mer
(2021/03/29)

Magnetic covalently immobilized nickel complex: A new and efficient method for the Suzuki cross-coupling reaction
In this study, an efficient procedure was reported to prepare Fe3O4@SiO2 magnetic nanoparticles (MNPs) with immobilized nickel NPs. In order to increase the activity of this catalyst, creatine as a ligand with high content of nitrogen atoms was linked onto the magnetic core–shell structure. Then, Ni(II) ions were coordinated on the surface of the silica-coated MNPs and reduced to Ni(0) NPs to obtain the final catalyst. The catalytic activity of the prepared catalyst was studied for the synthesis of biaryl derivatives via the Suzuki–Miyaura cross-coupling reaction in high yields. The catalyst could also be recovered and reused with no loss of activity over five successful runs.
Keyhaniyan, Mahdi,Khojastehnezhad, Amir,Eshghi, Hossein,Shiri, Ali
(2021/01/12)

Coordination from Heteroscorpionate Ligand Towards Pd(II) via Pd???Hδ?C(sp3) Interaction: Structural and Catalytic Studies
The coordination ability of the heteroscorpionate ligand 2,2-bis(3,5-dimethylpyrazol-1-yl)-1-p-tolylethanol (1) towards palladium (II) dihalides was evaluated. The structures of the respective palladium complexes (2 and 3) were elucidated in solution by NMR spectroscopy, and their molecular structures were established by single crystal X-ray diffraction analyses. Both studies revealed the existence of Pd???Hδ?C(sp3) anagostic interactions. The molecular structure of complexes 2 and 3 displays coordination of ligand 1 to palladium in a κ3-NNH tridentate fashion via two nitrogen atoms and one δ-anagostic H???Pd interaction. The metal center exhibits a square pyramidal geometry. The distances of anagostic Hδ???Pd interactions ranged from 2.566 to 2.576 ?. The δ-anagostic H???Pd interactions in complexes 2 and 3 were also identified by Bader's quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analysis. The catalytic efficiencies of complexes 2 and 3 in the Suzuki-Miyaura cross-coupling reactions were evaluated and the results showed that palladium (II) dibromide complex is the most efficient of the series. Complex 3 was also evaluated in Mizoroki-Heck cross-coupling reactions.
Castillo-Moreno, Miguel ángel,Cruz-Borbolla, Julián,González-Montiel, Simplicio,Ignacio Sandoval-Chávez, César,Manuel Vásquez-Pérez, José,Mendoza-Espinosa, Daniel,Salazar-Pereda, Verónica
supporting information
p. 2661 - 2668
(2021/07/06)

Pd salen complex@CPGO as a convenient, effective heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions
A Pd(II) Schiff base complex supported on graphene oxide nanosheets (Pd(II) salen@CPGO) has been synthesized and characterized by FT-IR, ICP-AES, XRD, SEM/EDX and TEM. The synthesized nanocatalyst has been found to be an efficient heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki coupling reactions. Pd(II) salen@CPGO could be separated and recovered easily from the reaction mixture and recycled several times without a discernible decrease in its catalytic activity. The construction of a solid sheet-supported Pd catalyst would be expected to be a promising system to perform heterogeneous catalytic reactions.
Ghabdian, Mahdieh,Nasseri, Mohammad Ali,Allahresani, Ali,Motavallizadehkakhky, Alireza
p. 1713 - 1728
(2018/05/25)

NiFe2O4@SiO2@ZrO2/SO42-/Cu/Co nanoparticles: A novel, efficient, magnetically recyclable and bimetallic catalyst for Pd-free Suzuki, Heck and C-N cross-coupling reactions in aqueous media
The novel heterogeneous bimetallic nanoparticles of Cu-Co were synthesized based on magnetic nanoparticles, and the magnetic nanocatalyst was characterized by XRD, FE-SEM, EDX mapping, BET, TEM, HRTEM, FTIR, TGA, and VSM. This catalyst was successfully applied as a recyclable magnetically catalyst in Heck, Suzuki, and C-N cross-coupling reactions with various aryl halides (iodides, bromides, and chlorides as challengeable substrates), with olefins, phenylboronic acid, and amines, respectively. We considered the rise of synergetic effects from the different Lewis acid and Br?nsted acid sites present in the catalyst. The catalyst was synthesized with cheap, available materials and a simple synthesis method. The catalyst can be separated easily using an external magnet. It was recycled for more than ten runs without a sensible loss of its catalytic activity, and no significant leaching of the Cu and Co quantity was observed. The significant benefits of the method are high-level generality, simple operation, and there are no heavy metals and toxic solvents. This is a quick, easy, efficacious and environmentally friendly protocol, and no by-products are formed in the reaction. These features make it an appropriate practical alternative protocol. In comparison with recent works, the other advantage of this catalyst is the synthesis of a wide variety of C-C and C-N bond derivatives (more than 40 derivatives). The other significant advantage is the low temperature of the reaction and the use of the least possible amount of the catalyst (0.003 g). The efficiency was good to excellent and the catalyst selectivity has been high. We aspire that our study inspires more interest to design novel catalysts based on using low-cost metal ions (such as cobalt and copper) in the cross-coupling reactions. This journal is
Alavi G., Seyyedeh Ameneh,Nasseri, Mohammad Ali,Kazemnejadi, Milad,Allahresani, Ali,Hussainzadeh, Mahdi
p. 7741 - 7757
(2021/05/13)

New Nickel-Based Catalytic System with Pincer Pyrrole-Functionalized N-Heterocyclic Carbene as Ligand for Suzuki-Miyaura Cross-Coupling Reactions
A new catalytic system with Ni(NO3)2·6H2O as the catalyst and a pincer pyrrole-functionalized N-heterocyclic carbene as the ligand was employed in the Suzuki-Miyaura cross-coupling reactions of aryl iodides with arylboronic acids. With 5 mol% catalyst, the catalytic reactions proceeded at 160 °C, giving coupling products in isolated yields of up to 94% in short reaction times (1-4 h). The system worked efficiently with aryl iodides bearing electron-donating or electron-withdrawing groups and arylboronic acids with electron-donating groups. Steric effects were observed for both aryl iodides and arylboronic acids. It is proposed that the reactions underwent a Ni(I)/Ni(III) catalytic cycle.
Guo, Zhifo,Lei, Xiangyang
supporting information

(2021/09/11)

Highly efficient photocatalytic Suzuki coupling reaction by Pd3P/CdS catalyst under visible-light irradiation
Monodispersed palladium phosphide (Pd3P) (5.2 ± 0.5 nm) was firstly applied to photocatalytic Suzuki coupling reaction under visible light irradiation with CdS nanoflake as a photosensitizer. This heterogeneous system exhibited high yields to corresponding products and excellent stability in alcohol solvent at room temperature.
Yang, Huai-Qing,Chen, Qian-Qian,Liu, Fulai,Shi, Rui,Chen, Yong
p. 676 - 680
(2020/07/06)

Supported phosphine free bis-NHC palladium pincer complex: An efficient reusable nanocatalyst for Suzuki-Miyaura coupling reaction
A periodic mesoporous organosilica material functionalized with a bis-NHC palladium pincer complex was synthesized by sol-gel process. The resulting organic-inorganic hybrid nano material was characterized by XRD, TEM, SEM, TGA analysis, and BET measurements. The hybrid nanomaterial act as highly active catalysts for the Suzuki–Miyaura cross-coupling between deactivated aryl chlorides and phenylboronic acid under heterogeneous and aerobic conditions. The supported catalyst exhibited excellent activity and stability and it could be reused at least ten times without any significant loss of activity. Furthermore, the SEM image revealed that high order mesostructure of the recycled nanocatalyst. After ninth run, catalyst showed almost similar structure as compared to the fresh catalyst. ICP-AES detected no Pd contamination in the products, and leaching tests verified that the reaction was truly heterogeneous.
Burange, Anand S.,Luque, Rafael,Rajabi, Fatemeh,Voskressensky, Leonid G.
(2021/10/07)

Samarium-based Grignard-type addition of organohalides to carbonyl compounds under catalysis of CuI
Grignard-type additions were readily achieved under the mediation of CuI (10 mol%) and samarium (2 equiv.) by employing various organohalides,e.g.benzyl, aryl, heterocyclic and aliphatic halides (Cl, Br or I), and diverse carbonyl compounds (e.g.carbonic esters, carboxylic esters, acid anhydrides, acyl chlorides, ketones, aldehydes, propylene epoxides and formamides) to afford alcohols, ketones and aldehydes, respectively, with high efficiency and chemoselectivity, in which the organosamarium intermediate might be involved.
Liu, Chen,Liu, Yongjun,Qi, Yan,Song, Bin,Wang, Liang,Xiao, Shuhuan
supporting information
p. 6169 - 6172
(2021/06/30)

Easily synthesizable benzothiazole based designers palladium complexes for catalysis of Suzuki coupling: Controlling effect of aryl substituent of ligand on role and composition of insitu generated binary nanomaterial (PdS or Pd16S7)
The present report is based on straightforward synthesis of molecular palladium complexes of benzothiazole based bulky ligands. Catalytic potential of 1[Pd(L1)2Cl2] and 2[Pd(L2)2Cl2] has been screened for Suzuki coupling. Due to structural difference between 1 and 2 (anthracen-9-yl in 1, and pyren-1-yl in 2), they behave as designers pre-catalysts and show different catalytic behaviour and nature by dispensing the nanoparticles of different materials (PdS by 1 and Pd16S7 by 2). This is an unprecedented observation as the size of the aryl substituent controls the efficiency (efficiency: 1 > 2) through determining the composition and nature of insitu generated nanoparticles.
Arora, Aayushi,Kumar, Arun,Kumar, Sushil,Oswal, Preeti,Rao, Gyandshwar Kumar,Singh, Ajai K.,Singh, Siddhant
(2020/12/14)

Aerobic Cu and amine free Sonogashira and Stille couplings of aryl bromides/chlorides with a magnetically recoverable Fe3O4@SiO2 immobilized Pd(II)-thioether containing NHC
Two value added C–C cross coupling reactions; Sonogashira and Stille couplings were achieved at milder conditions in the catalytic presence of a magnetically recoverable heterogeneous catalyst Fe3O4@SiO2@NHC^SPh-Pd(II). The catalyst was earlier reported for Suzuki-Miyaura reaction, and as an extension of its catalytic efficiency, the Stille and Sonogashira cross coupling reactions under aerobic condition has been explored in present report. The Sonogashira coupling of aryl bromides and terminal alkynes produced an excellent yield (~96% at 0.25 mol% Pd) of the desired coupling product under copper and amines free conditions. Moreover, an excellent Stille coupling of readily available and more latent aryl chlorides and trialkylstannane was obtained (yields up to 95% at 0.25 mol% Pd) in absence of toxic fluorides additives. The broad substrate scope of the catalyst for both the coupling reactions and the magnetically recoverable feature of catalyst make this reaction highly desirable for industrial applications of present heterogeneous catalysis.
Khandaka, Himanshu,Sharma, Kamal Nayan,Joshi, Raj Kumar
supporting information

(2021/02/20)

Polydopamine-Encapsulated Dendritic Organosilica Nanoparticles as Amphiphilic Platforms for Highly Efficient Heterogeneous Catalysis in Water
Aqueous heterogeneous catalysis is a green, sustainable catalytic process that attracts increasing attention, but it often suffers from poor mass transfer, substrate adsorption and catalyst dispersion. Herein, we synthesized a type of amphiphilic core-shell catalysts with a hydrophilic polydopamine (PDA) shell and a hydrophobic dendritic organosilica nanoparticle (DON) core for heterogeneous catalysis in water. The hydrophilic shell allowed the catalyst dispersing well in water, and the hydrophobic core facilitated the absorption of organic reactants. The hierarchical core-shell structure facilitated rational arrangement of the location of catalytic species to match the reaction sequence. The obtained metal, enzyme and metal-enzyme amphiphilic catalysts demonstrated improved stability, selectivity and activity in aqueous reactions, including Pd-catalyzed cross-couplings (Suzuki, Liebeskind-Srogl, Heck and Sonogashira), enzymatic enantioselective reduction, chemoenzymatic cascade synthesis of chiral compounds and chemoenzymatic cascade degradation of organophosphates. The amphiphilic catalysts could be easily in situ recovered, and their high catalytic performance was sustained for five cycles.
Gao, Jing,Guo, Na,Jiang, Yanjun,Liu, Guanhua,Liu, Pengbo,Liu, Yunting,Wang, Zihan,Zhang, Lei
supporting information
p. 1975 - 1982
(2021/06/09)

Aerobic Alcohol Oxidation by a Zeolitic Octahedral Metal Oxide based on Iron Vanadomolybdates Under Mild Conditions
Zeolitic octahedral metal oxides are fully-inorganic crystalline materials with the multi-component redox property and the intrinsic microporosity. The redox active zeolitic iron vanadomolybdate acts as a catalyst for aerobic oxidation of primary aromatic alcohols. Molecular oxygen is able to be activated in the material due to the confinement effect of the micropore and the unique redox property of the framework. Different primary aromatic alcohols are oxidized by the material, and high alcohol conversion and aldehyde selectivity are achieved. The material is stable and able to be reused for 5 times without loss of activity.
Zhu, Qianqian,Yin, Shanshan,Zhou, Mengyuan,Wang, Jie,Chen, Chaomin,Hu, Panpan,Jiang, Xizhuo,Zhang, Zhenxin,Li, Yanshuo,Ueda, Wataru
p. 1763 - 1771
(2021/02/26)

Highly ordered mesoporous hybrid silica functionalized with ionic liquid framework supported copper and its application in the oxidation of alcohols
A highly ordered organic-inorganic hybrid nanomaterial containing copper N-heterocyclic carbene complex (Cu-NHC@Pyrm-OMS) was synthesized and characterized using various techniques including FTIR, MAS NMR, XRD, TGA, SEM, and TEM. Cu-NHC@Pyrm-OMS nanomaterial is highly efficient heterogeneous system towards the selective oxidation of primary and secondary alcohols to corresponding aldehydes and ketones under mild conditions. Moreover, the supported copper nanocatalyst exhibited outstanding stability and could be reused at least ten times, remaining almost unchanged from initial activity. This work has focused on sustainable and green chemistry that use recoverable nanocatalyst, clean oxidant and aqueous media.
Rajabi, Fatemeh,Bahrami, Nazli,Vessally, Esmail,Luque, Rafael
(2021/10/27)

A novel two-dimensional metal-organic framework as a recyclable heterogeneous catalyst for the dehydrogenative oxidation of alcohol and theN-arylation of azole compounds
A novel metal-organic framework (MOF) with two-dimensional (2D) crystal structure was developed using Cu(NO3)2·3H2O and 2,2′,5,5′-tetramethoxy-[1,1′-biphenyl]-4,4′-dicarboxylic acid. Further, its structure was characterized using infrared spectroscopy, thermogravimetry, X-ray diffraction, and X-ray crystallography. The activated Cu-MOF was used to catalyze the dehydrogenative oxidation of alcohol andN-arylation of azole compounds. Furthermore, it could be easily recovered and reused.
Liu, Chengxin,Cui, Jin,Wang, Yufang,Zhang, Mingjie
p. 11739 - 11744
(2021/03/31)

Fe(III) superoxide radicals in halloysite nanotubes for visible-light-assisted benzyl alcohol oxidation and oxidative C[sbnd]C coupling of 2-naphthol
Selective oxidation of benzyl alcohols to aldehydes and 2-naphthol to BINOL was achieved by activation of molecular oxygen (O2) and hydrogen peroxide (H2O2) over an iron-oxide catalyst embedded in halloysite nanotube. Electron spin resonance spectroscopy (ESR), Raman and in situ FTIR spectroscopic analysis provided direct evidence for the involvement of superoxide radical bound FeIII species in the oxidation reaction. Both the analysis suggested the end-on binding of superoxide radical with FeIII-centre. The stability of such radical bound FeIII-species in halloysite nanotube was analyzed through density functional theory (DFT) calculations. Results suggested that end-on (η1) binding was favourable by 13.5 kcal/ mol than the side-on (η2) binding mode. The formation of such reactive species was believed to play the crucial role in bringing the high selectivity in the catalytic oxidation of benzyl alcohol and oxidative C[sbnd]C coupling of 2-naphthol. UV–Vis spectroscopic studies on the oxidation of benzyl alcohol suggested for the initial adsorption of substrate molecule on the catalyst surface followed by its interaction with FeIII -superoxide/hydroperoxide species generated upon photoirradiation with visible light in presence of O2. The presence of a suitable band gap ～2.14 eV enabled the catalyst to catalyze the reaction under visible light irradiation. Both the reactions (benzyl alcohol and 2-naphthol oxidation) were tested in presence of both O2 and H2O2 as oxidants at ambient temperature. The influence of different parameters like rate of oxygen flow, amount of peroxide, nature of solvent, and catalyst amount on the conversion and selectivity of the reactions were studied to understand their role in the catalytic reactions. Successful oxidation of 2-naphthol with H2O2 as oxidant was a real success to overcome the limitations associated with this reaction using H2O2 as oxidant.
Bania, Kusum K.,Baruah, Manash J.,Bora, Tonmoy J.,Dutta, Rupjyoti,Guha, Ankur Kanti,Roy, Subhasish
(2021/09/20)

4CzIPN catalyzed photochemical oxidation of benzylic alcohols
A green photoredox oxidation of benzylic primary and secondary alcohols to aldehydes and ketones with air as an oxidant was reported. The oxidation shows broad substrate scope and excellent selectivity over benzylic alcohols to the aliphatic alcohols. Further mechanistic studies revealed a quinuclidine mediated HAT process, and blue LEDs promoted 4CzlPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) photoredox cycle were involved in our oxidation.
Zhang, Heng,Guo, Tianyun,Wu, Mingzhong,Huo, Xing,Tang, Shouchu,Wang, Xiaolei,Liu, Jian
supporting information

(2021/02/20)

Visible-light photocatalytic selective oxidation of C(sp3)-H bonds by anion-cation dual-metal-site nanoscale localized carbon nitride
Selective oxidation of C(sp3)-H bonds to carbonyl groups by abstracting H with a photoinduced highly active oxygen radical is an effective method used to give high value products. Here, we report a heterogeneous photocatalytic alkanes C-H bonds oxidation method under the irradiation of visible light (λ= 425 nm) at ambient temperature using an anion-cation dual-metal-site modulated carbon nitride. The optimized cation (C) of Fe3+or Ni2+, with an anion (A) of phosphotungstate (PW123?) constitutes the nanoscale dual-metal-site (DMS). With a Fe-PW12dual-metal-site as a model (FePW), we demonstrate a A-C DMS nanoscale localized carbon nitride (A-C/g-C3N4) exhibiting a highly enhanced photocatalytic activity with a high product yield (86% conversion), selectivity (up to 99%), and a wide functional group tolerance (52 examples). The carbon nitride performs the roles of both the visible light response, and improves the selectivity for the oxidation of C(sp3)-H bonds to carbonyl groups, along with the function of A-C DMS in promoting product yield. Mechanistic studies indicate that this reaction follows a radical pathway catalyzed by a photogenerated electron and hole on A-C/g-C3N4that is mediated by thetBuO˙ andtBuOO˙ radicals. Notably, a 10 g scale reaction was successfully achieved for alkane photocatalytic oxidation to the corresponding product with a good yield (80% conversion), and high selectivity (95%) under natural sunlight at ambient temperature. In addition, this A-C/g-C3N4photocatalyst is highly robust and can be reused at least six times and the activity is maintained.
Duan, Limei,Li, Peihe,Li, Wanfei,Liu, Jinghai,Liu, Ying,Liu, Zhifei,Lu, Ye,Sarina, Sarina,Wang, Jinghui,Wang, Yin,Wang, Yingying,Zhu, Huaiyong
p. 4429 - 4438
(2021/07/12)

Oxidation of alcohols to aldehydes with bromoisobutyrate and dimethyl sulfoxide
We have developed an efficient oxidation of primary alcohols to aldehydes with ethyl bromoisobutyrate and dimethyl sulfoxide. Diaryl ketone can also be prepared under this reaction system.
Wu, Fei-Yue,Chen, Xiao-Hui,Zhou, Hai-Mei,Li, Jia-Qin,Cui, Hai-Lei
supporting information

(2021/09/29)

Mild oxidation of benzyl alcohols to benzyl aldehydes or ketones catalyzed by visible light
Induced by visible light, mild oxidation condition to prepare benzyl aldehydes or ketones have been developed by using bromotrichloromethane as photochemical oxidant. This method avoids high temperature, pressure and peroxidation with only visible light as the green driving force.
Cheng, Dongping,Li, Xiaonian,Ren, Shujian,Xu, Xiaoliang
supporting information

(2021/07/02)

Three-Dimensional Radical Covalent Organic Frameworks as Highly Efficient and Stable Catalysts for Selective Oxidation of Alcohols
With excellent designability, large accessible inner surface, and high chemical stability, covalent organic frameworks (COFs) are promising candidates as metal-free heterogeneous catalysts. Here, we report two 3D radical-based COFs (JUC-565 and JUC-566) in which radical moieties (TEMPO) are uniformly decorated on the channel walls via a bottom-up approach. Based on grafted functional groups and suitable regular channels, these materials open up the application of COFs as highly efficient and selective metal-free redox catalysts in aerobic oxidation of alcohols to relevant aldehydes or ketones with outstanding turn over frequency (TOF) up to 132 h?1, which has exceeded other TEMPO-modified catalytic materials tested under similar conditions. These stable COF-based catalysts could be easily recovered and reused for multiple runs. This study promotes potential applications of 3D functional COFs anchored with stable radicals in organic synthesis and material science.
Chen, Fengqian,Ding, Jiehua,Fang, Qianrong,Guan, Xinyu,Li, Hui,Qiu, Shilun,Tang, Bin,Valtchev, Valentin,Yan, Yushan,Zhu, Liangkui
supporting information
p. 22230 - 22235
(2021/09/03)

An aerobic oxidation of alcohols into carbonyl synthons using bipyridyl-cinchona based palladium catalyst
We have reported an aerobic oxidation of primary and secondary alcohols to respective aldehydes and ketones using a bipyridyl-cinchona alkaloid based palladium catalytic system (PdAc-5) using oxygen at moderate pressure. ThePdAc-5catalyst was analysed using SEM, EDAX, and XPS analysis. The above catalytic system is used in experiments for different oxidation systems which include different solvents, additives, and bases which are cheap, robust, non-toxic, and commercially available on the industrial bench. The obtained products are quite appreciable in both yield and selectivity (70-85%). In addition, numerous important studies, such as comparisons with various commercial catalysts, solvent systems, mixture of solvents, and catalyst mole%, were conducted usingPdAc-5. The synthetic strategy of oxidation of alcohol into carbonyl compounds was well established and all the products were analysed using1H NMR,13CNMR and GC-mass analyses.
Cheedarala, Ravi Kumar,Chidambaram, Ramasamy R.,Siva, Ayyanar,Song, Jung Il
p. 32942 - 32954
(2021/12/02)

Facile synthesis of NC(sp3)O pincer palladium complexes and their use as efficient catalysts for Suzuki-Miyaura reaction of aryl bromides in aqueous medium
Two NC(sp3)O pincer palladium(II) complexes 3a-3b were readily prepared in high yields in only two steps. Of the first step, catalytic hydrophosphination of 2-alkenoylpyridines and subsequent in situ phosphine oxidation produced the NC(sp3)O pincer preligands 2a-2b. The second step is palladation of the preligands 2a-2b where PdCl2 was used as the Pd source to afford the desired Pd pincers 3a-3b via C(sp3)-H bond activation. Single crystal X-ray diffraction analysis of complex 3a unambiguously confirmed the NCO tridentate coordination mode of the complexes. The two complexes 3a-3b were applied to catalyze the Suzuki-Miyaura reaction. Complex 3b was found to be more efficient and exhibited very high activity in the Suzuki reaction of structurally diverse aryl bromides with arylboronic acids in aqueous ethanol under air. At a reaction temperature of 70 °C, a TON of up to 1.9 × 105 and a TOF of up to 9800 h?1 were achieved. At lower temperatures 3b was still very active, giving a TON of up to 9.5 × 103 and a TOF of up to 3900 h?1 at room temperature.
Gong, Jun-Fang,Li, Nan,Pan, Ya-Ping,Song, Mao-Ping,Yang, Jing-Jing,Zhu, Zhi-Wu
(2020/12/15)

One-Pot Direct Oxidation of Primary Amines to Carboxylic Acids through Tandem ortho-Naphthoquinone-Catalyzed and TBHP-Promoted Oxidation Sequence
Biomimetic oxidation of primary amines to carboxylic acids has been developed where the copper-containing amine oxidase (CuAO)-like o-NQ-catalyzed aerobic oxidation was combined with the aldehyde dehydrogenase (ALDH)-like TBHP-mediated imine oxidation protocol. Notably, the current tandem oxidation strategy provides a new mechanistic insight into the imine intermediate and the seemingly simple TBHP-mediated oxidation pathways of imines. The developed metal-free amine oxidation protocol allows the use of molecular oxygen and TBHP, safe forms of oxidant that may appeal to the industrial application.
Kim, Hun Young,Oh, Kyungsoo,Si, Tengda
supporting information
p. 18150 - 18155
(2021/12/09)

Selective oxidation of alkenes to carbonyls under mild conditions
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
supporting information
p. 5549 - 5555
(2021/08/16)

Aryl aldiketone and synthesis method thereof
The invention discloses an aryl aldehyde ketone and a synthesis method thereof, wherein an aryl aldehyde is synthesized from cheap olefin as a raw material. A commercially available inexpensive olefin is used as a raw material, ether is used as an additive, molecular oxygen serves as a sole oxidizing agent, water is used as a solvent, and the aldehyde and ketone are synthesized by column chromatography under a photocatalytic condition. The invention has the advantages of mild reaction conditions, green and environmental protection, simple experimental operation, good reaction selectivity, high product yield and the like.
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Paragraph 0015

(2021/09/26)

V2O5@TiO2 Catalyzed Green and Selective Oxidation of Alcohols, Alkylbenzenes and Styrenes to Carbonyls
The versatile application of different functional groups such as alcohols (1° and 2°), alkyl arenes, and (aryl)olefins to construct carbon-oxygen bond via oxidation is an area of intense research. Here, we report a reusable heterogeneous V2O5@TiO2 catalyzed selective oxidation of various functionalities utilizing different mild and eco-compatible oxidants under greener reaction conditions. The method was successfully applied for the alcohol oxidation, oxidative scission of styrenes, and benzylic C?H oxidation to their corresponding aldehydes and ketones. The utilization of mild and eco-friendly oxidizing reagents such as K2S2O8, H2O2 (30 % aq.), TBHP (70 % aq.), broad substrate scope, gram-scale synthesis, and catalyst recyclability are notable features of the developed protocol.
Upadhyay, Rahul,Kumar, Shashi,Maurya, Sushil K.
p. 3594 - 3600
(2021/07/02)

Hydroxyl radical-mediated oxidative cleavage of CC bonds and further esterification reaction by heterogeneous semiconductor photocatalysis
A hydroxyl radical-mediated aerobic cleavage of alkenes and further sequence esterification reaction for the preparation of carbonyl compounds have been developed by using tubular carbon nitride (TCN) as a general heterogeneous photocatalyst under an oxygen atmosphere with visible light irradiation. This protocol has an excellent substrate scope and gives the desired aldehydes, ketones and esters in moderate to high yields. Importantly, this metal-free procedure employed photogenerated hydroxyl radicals in situ as green oxidation active species, avoiding the present additional initiators. The reaction could be carried out under solar light irradiation and was applicable to large-scale reactions. Furthermore, the recyclable TCN catalyst could be used several times without a significant loss of activities.
Hong, Mei,Jia, Rui,Miao, Hongyan,Ni, Bangqing,Niu, Tengfei,Wang, Hui
p. 6591 - 6597
(2021/09/10)

Method for preparing aldehyde compounds by oxidative cleavage of carbon-carbon bonds of terminal alkene compounds
The invention discloses a method for preparing aldehyde compounds by oxidizing and breaking carbon-carbon bonds of terminal alkene compounds. The method comprises the following steps: adding an alkene-terminated compound, an additive and a nitrogen-doped mesoporous carbon-loaded monatomic catalyst into a fatty primary alcohol solvent, putting into a pressure container, sealing, introducing oxygen source gas with a certain pressure, controlling the pressure of the oxygen source gas to be 0.1-1MPa and the reaction temperature to be 80-150 DEG C, and obtaining a reaction product, namely the aldehyde compound. The nitrogen-doped mesoporous carbon-loaded monatomic catalyst adopted by the invention is high in activity, the highest separation yield of the aldehyde compound as a reaction product reaches 99%, the method is wide in application range, the reaction conditions are easy to control, the catalyst can be recycled, the post-treatment is simple, and the method is suitable for industrial production.
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Paragraph 0061-0062; 0089-0090

(2021/06/06)

Synthesis of biaryl ketones and biaryl diketones via carbonylative Suzuki-Miyaura coupling reactions catalyzed by bridged bis(N-heterocyclic carbene)palladium(II) catalysts
This disclosure relates to bridged bis(N-heterocyclic carbene)palladium(II) complexes, methods of preparing the complexes, and methods of using the complexes in Suzuki-Miyaura coupling reactions.
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Page/Page column 20; 25-30

(2021/12/23)

METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst; wherein, the catalyst is represented by Formula (II): M(O)mL1yL2z??(II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):
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Paragraph 0071; 0077

(2021/07/10)

METHOD FOR OXIDATIVE CLEAVAGE OF COMPOUNDS WITH UNSATURATED DOUBLE BOND
A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method comprises the following step: (A) providing a compound (I) with an unsaturated double bond, a reagent with trifluoromethyl, and a catalyst; wherein the catalyst is represented by the following formula (II): M(O)mL1yL2z (II); wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and (B) mixing the compound with an unsaturated double bond and the reagent with a trifluoromethyl to perform an oxidation of the compound with the unsaturated double bond by using the catalyst at air or an oxygen condition to get a compound presented as formula (III):
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Paragraph 0053-0054; 0062-0063

(2021/03/19)

Gold Catalysts Can Generate Nitrone Intermediates from a Nitrosoarene/Alkene Mixture, Enabling Two Distinct Catalytic Reactions: A Nitroso-Activated Cycloheptatriene/Benzylidene Rearrangement
Gold-catalyzed reactions of cycloheptatrienes with nitrosoarenes yield nitrone derivatives efficiently. This reaction sequence enables us to develop gold-catalyzed aerobic oxidations of cycloheptatrienes to afford benzaldehyde derivatives using CuCl and nitrosoarenes as co-catalysts (10-30 mol %). Our density functional theory calculations support a novel nitroso-activated rearrangement, tropylium → benzylidene. With the same nitrosoarenes, we developed their gold-catalyzed [2 + 2 + 1]-annulations between nitrosobenzene and two enol ethers to yield 5-alkoxyisoxazolidines using 1,4-cyclohexadienes as hydrogen donors.
Cheng, Mu-Jeng,Kardile, Rahul Dadabhau,Kuo, Tung-Chun,Liu, Rai-Shung,More, Sayaji Arjun
supporting information
p. 5506 - 5511
(2021/07/31)

Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.
Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
(2021/01/11)

Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
supporting information
p. 10632 - 10636
(2021/04/09)

Photo-induced deep aerobic oxidation of alkyl aromatics
Oxidation is a major chemical process to produce oxygenated chemicals in both nature and the chemical industry. Presently, the industrial manufacture of benzoic acids and benzene polycarboxylic acids (BPCAs) is mainly based on the deep oxidation of polyalkyl benzene, which is somewhat suffering from environmental and economical disadvantage due to the formation of ozone-depleting MeBr and corrosion hazards of production equipment. In this report, photo-induced deep aerobic oxidation of (poly)alkyl benzene to benzene (poly)carboxylic acids was developed. CeCl3 was proved to be an efficient HAT (hydrogen atom transfer) catalyst in the presence of alcohol as both hydrogen and electron shuttle. Dioxygen (O2) was found as a sole terminal oxidant. In most cases, pure products were easily isolated by simple filtration, implying large-scale implementation advantages. The reaction provides an ideal protocol to produce valuable fine chemicals from naturally abundant petroleum feedstocks. [Figure not available: see fulltext.].
Wang, Chang-Cheng,Zhang, Guo-Xiang,Zuo, Zhi-Wei,Zeng, Rong,Zhai, Dan-Dan,Liu, Feng,Shi, Zhang-Jie
p. 1487 - 1492
(2021/07/10)

Potent Inhibition of Nicotinamide N-Methyltransferase by Alkene-Linked Bisubstrate Mimics Bearing Electron Deficient Aromatics
Nicotinamide N-methyltransferase (NNMT) methylates nicotinamide (vitamin B3) to generate 1-methylnicotinamide (MNA). NNMT overexpression has been linked to a variety of diseases, most prominently human cancers, indicating its potential as a therapeutic target. The development of small-molecule NNMT inhibitors has gained interest in recent years, with the most potent inhibitors sharing structural features based on elements of the nicotinamide substrate and the S-adenosyl-l-methionine (SAM) cofactor. We here report the development of new bisubstrate inhibitors that include electron-deficient aromatic groups to mimic the nicotinamide moiety. In addition, a trans-alkene linker was found to be optimal for connecting the substrate and cofactor mimics in these inhibitors. The most potent NNMT inhibitor identified exhibits an IC50 value of 3.7 nM, placing it among the most active NNMT inhibitors reported to date. Complementary analytical techniques, modeling studies, and cell-based assays provide insights into the binding mode, affinity, and selectivity of these inhibitors.
Buijs, Ned,Campagna, Roberto,Emanuelli, Monica,Gao, Yongzhi,Gutiérrez-De-Terán, Hugo,Innocenti, Paolo,Jespers, Willem,Martin, Nathaniel I.,Parsons, Richard B.,Sartini, Davide,Van Haren, Matthijs J.,Van Westen, Gerard J. P.,Zhang, Yurui
p. 12938 - 12963
(2021/09/11)

Controlling Multiple Active Sites on Pd?CeO2 for Sequential C?C Cross-coupling and Alcohol Oxidation in One Reaction System
Ceria (CeO2)-supported metal catalysts have been widely utilized for various single-step chemical transformations. However, using such catalysts for a multistep organic reaction in one reaction system has rarely been achieved. Here, we investigate multiple active sites on Pd?CeO2 catalysts and optimize them for a multistep reaction of C?C cross-coupling and alcohol oxidation. Atomic-level imaging and spectroscopic studies reveal that metallic Pd0 and Pd?CeO2 interface are active sites on Pd?CeO2 for C?C cross-coupling and oxidation, respectively. These active sites are controlled under the structural evolution of Pd?CeO2 during reductive heat-treatments. Accordingly, we found that optimally reduced Pd?CeO2 catalysts containing ～1.5 nm-sized Pd nanoclusters with both sites in balance are ideal for multistep chemical transformations in one reaction system. Our strategy to design supported metal catalysts leads to one-pot sequential synthetic protocols for pharmaceutical building blocks.
Antink, Wytse Hooch,Bok, Jinsol,Cho, Sung-Pyo,Choi, Hyunwoo,Hyeon, Taeghwan,Jung, Yoon,Kim, Do Heui,Kim, Jiheon,Kim, Jongchan,Kim, Ju Hee,Kim, Sumin,Kim, Young Gyu,Ko, Wonjae,Kwak, Minjoon,Lee, Byoung-Hoon,Lee, Chan Woo,Lee, Eunwon,Lee, Kug-Seung,Lee, Seong Chan,Yim, Guk Hee,Yoo, Dongwon
(2022/01/22)

Pd@COF-QA: A phase transfer composite catalyst for aqueous Suzuki-Miyaura coupling reaction
A Pd NP-loaded and paraffin-chain quaternary ammonium salt-decorated covalent organic framework, Pd@COF-QA, and its chitosan aerogel-based continuous flow-through reactor, which could be an excellent phase transfer catalyst to promote the aqueous Suzuki-Miyaura coupling reaction, is reported.
Wang, Jian-Cheng,Liu, Cong-Xue,Kan, Xuan,Wu, Xiao-Wei,Kan, Jing-Lan,Dong, Yu-Bin
p. 1150 - 1155
(2020/03/11)

C-C coupling formation using nitron complexes
A series of RuII (1), RhIII (2), IrIII (3, 4), IrI (5) and PdII (6-9) complexes of the 'instant carbene' nitron were prepared and characterized by 1H- and 13C-NMR, FT-IR and elemental analysis. The molecular structures of complexes 1-4 and 6 were determined by X-ray diffraction studies. The catalytic activity of the complexes (1-9) was evaluated in alpha(α)-alkylation reactions of ketones with alcohol via the borrowing hydrogen strategy under mild conditions. These complexes were able to perform this catalytic transformation in a short time with low catalyst and base amounts under an air atmosphere. Also, the PdII-nitron complexes (6-9) were applied in the Suzuki-Miyaura C-C coupling reaction and these complexes successfully initiated this reaction in a short time (30 minutes) using the H2O/2-propanol (1.5?:?0.5) solvent system. The DFT calculations revealed that the Pd0/II/0 pathway was more preferable for the mechanism
Sevim, Mehmet,Kavukcu, Serdar Batikan,Kinal, Arma?an,?ahin, Onur,Türkmen, Hayati
supporting information
p. 16903 - 16915
(2020/12/18)

FeCl3-catalyzed oxidative decarboxylation of aryl/heteroaryl acetic acids: Preparation of selected API impurities
There is an ever-increasing demand for impurity compounds for use in impurity profiling as regulatory agencies seek information during registration. Herein, we report the FeCl3-catalyzed oxidative decarboxylation of aryl- and heteroaryl acetic acids to the corresponding carbonyl compounds. A variety of useful aldehydes and ketones were prepared in a simple one-pot transformation by employing an environmentally benign, low-cost, and readily available iron salt. The utility of this method has been demonstrated by preparing five valuable API impurities including a multi-gram-scale synthesis of ketorolac impurity B for the first time. This journal is
Gangadurai, Chinnakuzhanthai,Illa, Giri Teja,Reddy, D. Srinivasa
p. 8459 - 8466
(2020/11/05)

Amino-Induced 2D Cu-Based Metal–Organic Framework as an Efficient Heterogeneous Catalyst for Aerobic Oxidation of Olefins
With the assistance of hydrogen bonds of the o-amino group, we have successfully tuned a coordination structure from a metal–organic polyhedron (MOP) to a two-dimensional (2D) metal–organic framework (MOF). The amino group forms hydrogen bonds with the two vicinal carboxylic groups, and induces the ligand to coordinate with copper ions to form the 2D structure. The obtained 2D Cu-based MOF (Cu-AIA) has been applied as an efficient heterogeneous catalyst in the aerobic epoxidation of olefins by using air as oxygen source. Without the aggregation problem of active sites in MOPs, Cu-AIA possesses much higher reactivity than MOP-1. Furthermore, the amino group of the framework has been used as a modifiable site through post-synthetic metalation (PSMet) to prepare a 2D MOF-supported Pd single-site heterogeneous catalyst, which shows excellent catalytic performance for the Suzuki reaction. It indicates that Cu-AIA can also work as a good 2D MOF carrier for the derivation of other heterogeneous catalysts.
Bao, Shixiong,Cai, Mengke,Ding, Shujiang,Li, Guangqin,Tang, Jia,Tao, Jinzhang,Wang, Xiaoxia,Xie, Guanqun
supporting information

(2020/03/13)