103-65-1Relevant articles and documents
ZUR BILDUNGSWEISE VON 1-PHENYLPROPYLLITHIUM AUS BENZYLLITHIUM UND ETHYLEN IN TETRAHYDROFURAN
Maercker, Adalbert,Stoetzel, Reinhard
, p. 1 - 12 (1983)
3-Phenylpropyllithium primarily formed by the addition of benzyllithium to ethylene in THF does not undergo an intramolecular 1,3-proton shift to 1-phenylpropyllithium.Fast protonation by the solvent takes place instead, yielding n-propylbenzene and new ethylene.An equilibrium is then established between n-propylbenzene and additional benzyllithium, with the formation of toluene and 1-phenylpropyllithium; the equilibrium, however, strongly favours the starting materials (K293=1.1*10-4).As, on the other hand, 1-phenylpropyllithium reacts with ethylene much more rapidly than does benzyllithium, it is removed from the equilibrium and mainly branched secondary products are still obtained.
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Ipatieff,Pines,Schmerling
, p. 253,259 (1940)
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Salt-free preparation of trimethylsilyl ethers by B(C6F 5)3-catalyzed transfer silylation by using a Me 3SiH surrogate
Simonneau, Antoine,Friebel, Jonas,Oestreich, Martin
, p. 2077 - 2083 (2014)
An unprecedented transfer silylation of alcohols catalyzed by the strong Lewis acid B(C6F5)3 is described. Gaseous Me3SiH is released in situ by B(C6F5) 3-catalyzed decomposition of 3-trimethylsilylcyclohexa-1,4-diene and subsequently reacts with an alcohol in a dehydrogenative Si-O coupling promoted by the same boron catalyst. Benzene and dihydrogen are formed during the reaction, but no salt waste is. This expedient protocol is applicable to several silicon groups, and the preparation of trimethylsilyl ethers presented here is potentially useful for alcohol derivatization prior to GLC analysis. Copyright
Distribution of Metal Cations in Ni-Mo-W Sulfide Catalysts
Hein, Jennifer,Gutiérrez, Oliver Y.,Schachtl, Eva,Xu, Pinghong,Browning, Nigel D.,Jentys, Andreas,Lercher, Johannes A.
, p. 3692 - 3704 (2015)
The distribution of metal cations and the morphology of unsupported NiMo, NiW, and NiMoW sulfide catalysts were explored qualitatively and quantitatively. In the bi- and trimetallic catalysts, Mo(W)S2 nanoparticles are deposited on Ni sulfide particles of varying stoichiometry and sizes (crystalline Ni9S8, and Ni3S4 were identified). These nanoparticles are stacks of Mo(W)S2 slabs with varying size, degrees of bending and mismatch between the slabs. High resolution electron microscopy and X-ray absorption spectroscopy based on particle modeling revealed a statistical distribution of Mo and W within individual layers in sulfide NiMoW, forming intralayer mixed Mo1-xWxS2. Ni is associated with MoS2, WS2, and Mo1-xWxS2 creating Ni-promoted phases. The incorporation of Ni at the edges of the slabs was the highest for sulfide NiMoW. This high concentration of Ni in sulfide NiMoW, as well as its long bent Mo1-xWxS2 slabs, were paralleled by the highest activity for nitrogen and sulfur removal from model hydrocarbons such as o-propylaniline and dibenzothiophene.
Transfer hydrogenation of alkenes using Ni/Ru/Pt/Au heteroquatermetallic nanoparticle catalysts: Sequential cooperation of multiple nano-metal species
Ito, Yoshikazu,Ohta, Hidetoshi,Yamada, Yoichi M. A.,Enoki, Toshiaki,Uozumi, Yasuhiro
, p. 12123 - 12126 (2014)
Quatermetallic alloy nanoparticles of Ni/Ru/Pt/Au were prepared and found to promote the catalytic transfer hydrogenation of non-activated alkenes bearing conjugating units (e.g., 4-phenyl-1-butene) with 2-propanol, where the composition metals, Ni, Ru, Pt, and Au, act cooperatively to provide significant catalytic ability. This journal is
Pd nanoparticles confined in mesoporous N-doped carbon silica supports: A synergistic effect between catalyst and support
Kerstien, Julius,Oliveira, Rafael L.,Schom?cker, Reinhard,Thomas, Arne
, p. 1385 - 1394 (2020)
Palladium nanoparticles of similar size were deposited on different supports, layers of carbon materials (with and without nitrogen doping) on the surface of a MCF (mesocellular foam) silica. For the generation of the N-doped carbon coatings, three different N sources were used to also investigate a possible influence of the N-doped carbon precursor and thus the structure of the N-doped carbons on their performance as catalyst support. These catalysts were tested for the Suzuki coupling and hydrogenation reactions. For the Suzuki reaction, the carbon coatings showed to increase dramatically the stability of the MCF material. Furthermore, when N-doped carbon coatings were applied, strong improvement of the stability of the catalysts was observed due to an enhanced interaction between metal nanoparticles and the support, preventing metal particle growth. In hydrogenation reactions, the presence of the N-doped carbon coating on the silica support increases the adsorption of aromatic compounds causing an enhancement of the catalytic activity of Pd NPs when compared to the non-doped supports.
Convenient preparation of metals deposited on solid supports and their use in organic synthesis
Majkosza, Mieczyslaw,Nieczypor, Piotr,Grela, Karol
, p. 10827 - 10836 (1998)
'High-surface alkali metals' can be conveniently prepared via deposition of corresponding metals on various supports such as sodium chloride, polyethylene, polypropylene and cross-linked polystyrene from their solutions in liquid ammonia. Alkali metals deposited on polymeric supports can be stored in form of stable suspensions in inert solvents and used for the acyloin and Dieckmann condensations and for preparation of organolithiums. Addition of the suspension of supported alkali metal to a solution of zinc chloride gave an active zinc on polymeric support, which can be used for the Reformatski and Barbier reactions.
Reaction Calorimetry in Microreactor Environments - Measuring Heat of Reaction by Isothermal Heat Flux Calorimetry
Glotz, Gabriel,Knoechel, Donald J.,Podmore, Philip,Gruber-Woelfler, Heidrun,Kappe, C. Oliver
, p. 763 - 770 (2017)
A novel setup to analyze the heat of reaction of different single- and multiphase reactions carried out in continuous flow is presented. The measurement principle of the calorimetric system is based on true heat flow measurements and therefore ensures precise calorimetric data within 10 mW resolution. In addition to the investigation of simple mixing phenomena (ethylene glycol and water), a number of exothermic, industrially relevant chemical transformations including the nitration of phenol, the reduction of nitrobenzene, as well as several oxidation and reduction processes, were investigated as model systems. For these experiments a commercially available batch calorimeter (ChemiSens CPA202) was equipped with a glass static mixer (250 μL) optionally connected to a tubular microreactor (PFA coil) allowing overall reaction volumes of up to ca. 5.5 mL. Experiments were performed by feeding individual streams with syringe pumps (alternatively substituting one liquid feed with a gaseous feed controlled by a mass flow controller) and mixing the feeds inside the glass static mixer contained in the thermostatted reactor zone of the calorimeter. By adjusting the residence time, volume, and flow rates, chemical transformations were driven to full conversion in order to obtain meaningful calorimetric data. A comparison with literature data indicates that the calorimetric flow system described herein provides comparable data to those obtained by standard batch calorimetry.
Chromow et al.
, p. 1360,1361; engl. Ausg. S. 1343, 1344 (1954)
Novel reaction of the low valent cobalt reagent generated using CoCl2 and NaBH4/C2H5OH in the presence of carbon monoxide
Satyanarayana, Nistala,Periasamy, Mariappan
, p. C33 - C36 (1987)
Low valent co balt species, prepared in situ in tetrahydrofuran (THF) by the reduction of CoCl2 with NaBH4/C2H5OH under carbon monoxide, isomerize of alkenes, reduce alkenes, and carbonylate benzyl halides under appropriate conditions.
Nickel boosts ring-opening activity of iridium
Ziaei-Azad, Hessam,Semagina, Natalia
, p. 885 - 894 (2014)
A variety of bimetallic Ni-Ir catalysts were synthesised by preforming nanoparticles in the presence of polyvinylpyrrolidone, followed by deposition on γ-alumina and high-temperature polymer removal. The Ni-Ir (1:1 molar ratio) nanoparticles prepared by the hydrogen-sacrificial technique (Ir reduction on the preformed Ni nanoparticles with surface Ni hydride) allowed increasing indane ring opening activity per total amount of Ir as compared to monometallic Ir. The simultaneous reduction of Ni and Ir precursors was not as efficient. The catalysts were characterised with UV/Vis spectroscopy, TEM, temperature-programmed reduction, CO2 temperature-programmed desorption, CO diffuse reflectance Fourier transform spectroscopy, X-ray photoelectron spectroscopy and CHN analysis. The study only explored the catalyst's metal function and allows saving rare and expensive iridium without loss of its outstanding performance as a ring-opening catalyst. Save the rare: To avoid inefficient use of rare and expensive catalytic metals, iridium atoms are placed only in the outermost layer of the nanoparticles, with inexpensive metal (nickel) inside, which boosts the catalytic performance.
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Soffer,Soffer,Sherk
, p. 1435,1436 (1945)
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Ionic liquid-initiated polymerization of epoxides: A useful strategy for the preparation of Pd-doped polyether catalysts
Arnold, Ulrich,Altesleben, Christiane,Behrens, Silke,Essig, Sarah,Lautenschütz, Ludger,Schild, Dieter,Sauer, J?rg
, p. 116 - 124 (2015)
Palladium compounds (Pd(OAc)2 and Pd(acac)2) were dissolved in commercially available epoxy resins (glycidyl derivatives of bisphenol A and p-aminophenol) and the formulations were polymerized employing the ionic liquid 1-ethyl-2-methylimidazolium acetate (EMIM acetate) as polymerization initiator. Thus, palladium species could be incorporated in the network of the resulting polyether materials. Polymerization reactions were investigated by DSC and the curing behavior of different formulations was compared. High polymerization enthalpies were observed indicating high crosslinking in the materials. Accordingly, the materials exhibited high glass transition temperatures and thermogravimetric data revealed high thermal stability. Due to the good solubility of the palladium compounds in the epoxy resins, a widely homogeneous dispersion of palladium species in the polyether matrix could be realized. This was confirmed by SEM-EDX and TEM measurements. XPS measurements revealed that reduction of Pd(II) to Pd(0) species occurred during catalyst preparation and this was also proven by XRD. The materials were ground and successfully employed as catalysts for the hydrogenation of several alkenes under mild reaction conditions. High conversions and selectivities could be reached within a few hours at room temperature and moderate hydrogen pressure of 2.5 bar. Palladium leaching from the catalysts to reaction solutions was investigated. To determine very low quantities, metal concentrations were enriched by removal of volatile components. Subsequent ICP-AES measurements revealed low palladium contents in the range of a few μg. These amounts correspond to values around 0.007% with respect to palladium originally loaded on the polymer. Catalyst recycling experiments were also carried out and it was shown that the catalysts can be employed in numerous consecutive reactions without any catalyst treatment and without loss of activity. Within a series of reactions, palladium leaching decreased while catalytic activity was not affected.
Activation of Reducing Agents. Sodium Hydride Containing Complex Reducing Agents. 33. NiCRA's and NiCRAL's as New Efficient Desulfurizing Reagents
Becker, Sandrine,Fort, Yves,Vanderesse, Regis,Caubere. Paul
, p. 4848 - 4853 (1989)
It is shown that nickel-containing complex reducing agents alone or in the presence of 2,2'-bipyridine (NiCRA and NiCRAL-bpy, respectively) are very efficient in the desulfurization of sulfur containing organic compounds.A number of functional groups are resistant.Advantages of the inexpensive and nonpyrophoric CRA's are their easy preparation and handling.The mechanism of these desulfuryzations are discussed and compared to those with Ni(0) complexes.
Coupling of titanacyclopentadienes with a cp ligand and elimination of one substituent
Mizukami, Yuki,Li, Haijun,Nakajima, Kiyohiko,Song, Zhiyi,Takahashi, Tamotsu
, p. 8899 - 8903 (2014)
Titanacyclopentadienes, prepared from [Cp2TiBu2] and either two equivalents of an alkyne or a diyne, were treated with PMe 3 (3 equiv) at 50C for 3 h and then with azobenzene at room temperature for 12 h to give 4,5,6-trisubstituted indene derivatives with the loss of one substituent in good yields. This reaction contrasts sharply with our previously reported reaction for the formation of 4,5,6,7-tetrasubstituted indene derivatives without the loss of substituents by the treatment of titanacyclopentadienes with azobenzene without PMe3. 13C NMR spectroscopy of the product derived from a 13C-enriched complex revealed that the five carbon atoms originating from a Cp ligand were arranged linearly in the trisubstituted indene derivatives, in contrast to the 4,5,6,7-tetrasubsituted indene derivatives, in which the corresponding five carbon atoms are arranged in a ring.
Continuous flow reduction of artemisinic acid utilizing multi-injection strategies - Closing the gap towards a fully continuous synthesis of antimalarial drugs
Pieber, Bartholom?us,Glasnov, Toma,Kappe, C. Oliver
, p. 4368 - 4376 (2015)
One of the rare alternative reagents for the reduction of carbon-carbon double bonds is diimide (HN=NH), which can be generated in situ from hydrazine hydrate (N2H4·H2O) and O2. Although this selective method is extremely clean and powerful, it is rarely used, as the rate-determining oxidation of hydrazine in the absence of a catalyst is relatively slow using conventional batch protocols. A continuous high-temperature/high-pressure methodology dramatically enhances the initial oxidation step, at the same time allowing for a safe and scalable processing of the hazardous reaction mixture. Simple alkenes can be selectively reduced within 10-20 min at 100-120°C and 20 bar O2 pressure. The development of a multi-injection reactor platform for the periodic addition of N2H4·H2O enables the reduction of less reactive olefins even at lower reaction temperatures. This concept was utilized for the highly selective reduction of artemisinic acid to dihydroartemisinic acid, the precursor molecule for the semisynthesis of the antimalarial drug artemisinin. The industrially relevant reduction was achieved by using four consecutive liquid feeds (of N2H4·H2O) and residence time units resulting in a highly selective reduction within approximately 40 min at 60°C and 20 bar O2 pressure, providing dihydroartemisinic acid in ≥93% yield and ≥95% selectivity.
Effective hydrodeoxygenation of lignin-derived phenols using bimetallic RuRe catalysts: Effect of carbon supports
Jung, Kyung Bin,Lee, Jinho,Ha, Jeong-Myeong,Lee, Hyunjoo,Suh, Dong Jin,Jun, Chul-Ho,Jae, Jungho
, p. 191 - 199 (2018)
We have previously shown that an activated carbon-supported ruthenium catalyst promoted with ReOx (RuRe/AC) is highly active for the hydrodeoxygenation (HDO) of lignin-derived phenols (e.g., guaiacol). In this work, we have investigated the effect of carbon supports on the structure and HDO activity of bimetallic RuRe particles using three different carbon supports, i.e., activated carbon (AC), carbon black (Vulcan carbon, VC), multi-walled carbon nanotube (MWCNT). The MWCNT- and VC-supported catalysts show remarkably enhanced activity and hydrocarbon selectivity for the HDO of a range of phenolic molecules (i.e., guaiacol, eugenol, benzyl phenyl ether) compared to RuRe/AC. STEM-EDS and XPS analyses reveal that bimetallic RuRe particles are more common than monometallic Ru or Re particles in the VC- and MWCNT-supported catalysts, and hexavalent rhenium species are more easily reduced to tetravalent rhenium during the HDO reactions in these catalysts, suggesting that Ru and Re in close proximity are required for the efficient hydrogenolysis of phenols. The formation of bimetallic particles on the AC surface is likely hindered by high microporosity and high surface oxygen functionalities, both of which restrict the mobility of Re and Ru for assembly.
COMPARATIVE INVESTIGATION OF THE CATALYTIC PROPERTIES OF CRYSTALLINE ALUMOSILICATES OF VARIOUS TYPES. COMMUNICATION 3. SELECTIVITY OF THE CONVERSION OF METHANOL ON ZEOLITES OF VARIOUS TYPES
Stepanov, V. G.,Gonyshev, A. P.,Ione, K. G.
, p. 1567 - 1572 (1982)
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CATALYTIC PROPERTIES OF GROUP VIII METAL COMPOUNDS SUPPORTED ON A POLYMERIC CARREIR. 3. NICKEL AND COBALT COMPLEXES SUPPORTED ON CARRIERS CONTAINING COORDINATION GROUPS BASED ON PHOSPHORUS IN THE HYDROGENATION AND ISOMERIZATION REACTIONS OF ALLYLBENZENE
Sukhobok, L. N.,Potapov, G. P.,Polkovnikov, B. D.,Luksha, V. G.,Krutii, V. N.
, p. 763 - 764 (1983)
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Hydrocarbon-soluble nanocatalysts with no bulk phase: Coplanar, two-coordinate arrays of the base metals
Camacho-Bunquin, Jeffrey,Ferguson, Michael J.,Stryker, Jeffrey M.
, p. 5537 - 5540 (2013)
A structurally unique class of hydrocarbon-soluble, ancillary-ligand-free, tetrametallic Co(I) and Ni(I) clusters is reported. The highly unsaturated complexes are supported by simple, sterically bulky phosphoranimide ligands, one per metal. The electron-rich nitrogen centers are strongly bridging but sterically limited to bimetallic interactions. The hydrocarbon-soluble clusters consist of four coplanar metal centers, mutually bridged by single nitrogen atoms. Each metal center is monovalent, rigorously linear, and two-coordinate. The clusters are in essence two-dimensional atomic-scale "molecular squares," a structural motif adapted from supramolecular chemistry. Both clusters exhibit high solution-phase magnetic susceptibility at room temperature, suggesting the potential for applications in molecular electronics. Designed to be catalyst precursors, both clusters exhibit high activity for catalytic hydrogenation of unsaturated hydrocarbons at low pressure and temperature.
An unprecedented iron-catalyzed cross-coupling of primary and secondary alkyl Grignard reagents with non-activated aryl chlorides
Perry, Marc C.,Gillett, Amber N.,Law, Tyler C.
, p. 4436 - 4439 (2012)
The use of N-heterocyclic carbene ligands in the iron-catalyzed cross-coupling of alkyl Grignards has allowed, for the first time, coupling of non-activated, electron rich aryl chlorides. Surprisingly, the tetrahydrate of FeCl2 was found to be a better pre-catalyst than anhydrous FeCl 2. Primary Grignard reagents coupled in excellent yields while secondary Grignard reagents coupled in modest yields. The use of acyclic secondary Grignard reagents resulted in the formation of isomers in addition to the desired product. These isomeric products were formed via reversible β-hydrogen elimination, indicating that the cross-coupling proceeds through an ionic pathway.
STRUCTURE AND CATALYTIC ACTIVITY OF SUPPORTED METAL COMPLEXES: COMMUNICATION 2. SYNTHESIS OF RHODIUM COMPLEXES ON SILICA GEL MODIFIED BY PHOSPHORUS- AND NIROGEN-CONTAINING LIGANDS
Dovganyuk, V. F.,Lafer, L. I.,Isaeva, V. I.,Dykh, Zh. L.,Yakerson, V. I.,Sharf, V. Z.
, p. 2465 - 2470 (1987)
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Irwin,McQuillin
, p. 1937 (1968)
Heterolysis of Dihydrogen by Nucleophilic Calcium Alkyls
Wilson, Andrew S. S.,Dinoi, Chiara,Hill, Michael S.,Mahon, Mary F.,Maron, Laurent
, p. 15500 - 15504 (2018)
β-Diketiminato (BDI) calcium alkyl derivatives undergo hydrogenolysis with H2 to regenerate [(BDI)CaH]2, allowing the catalytic hydrogenation of a wide range of 1-alkenes and norbornene under very mild conditions (2 bar H2, 298 K). The reactions are deduced to take place with the retention of the dimeric structures of the calcium hydrido-alkyl and alkyl intermediates via a well-defined sequence of Ca?H/C=C insertion and Ca?C hydrogenation events. This latter deduction is strongly supported by DFT calculations (B3PW91) performed on the 1-hexene/H2 system, which also indicates that the hydrogenation transition states display features which discriminate them from a classical σ-bond metathesis mechanism. In particular, NBO analysis identifies a strong second order interaction between the filled α-methylene sp3 orbital of the n-hexyl chain and the σ* orbital of the H2 molecule, signifying that the H?H bond is broken by what is effectively the nucleophilic displacement of hydride by the organic substituent.
Size- and structure-controlled mono- and bimetallic Ir-Pd nanoparticles in selective ring opening of indan
Ziaei-Azad, Hessam,Yin, Cindy-Xing,Shen, Jing,Hu, Yongfeng,Karpuzov, Dimitre,Semagina, Natalia
, p. 113 - 124 (2013)
Nearly monodispersed 1.6 nm Ir, 2.3 nm Pd nanoparticles, 2.7 nm Pd(core)-Ir(shell) and 2.2 nm Pd-Ir alloys with mixed surface atoms were synthesised in the presence of polyvinylpyrrolidone (PVP) and studied in the atmospheric ring opening of indan. The na
One-Pot Deoxygenation and Substitution of Alcohols Mediated by Sulfuryl Fluoride
Epifanov, Maxim,Mo, Jia Yi,Dubois, Rudy,Yu, Hao,Sammis, Glenn M.
, p. 3768 - 3777 (2021/03/01)
Sulfuryl fluoride is a valuable reagent for the one-pot activation and derivatization of aliphatic alcohols, but the highly reactive alkyl fluorosulfate intermediates limit both the types of reactions that can be accessed as well as the scope. Herein, we report the SO2F2-mediated alcohol substitution and deoxygenation method that relies on the conversion of fluorosulfates to alkyl halide intermediates. This strategy allows the expansion of SO2F2-mediated one-pot processes to include radical reactions, where the alkyl halides can also be exploited in the one-pot deoxygenation of primary alcohols under mild conditions (52-95% yield). This strategy can also enhance the scope of substitutions to nucleophiles that are previously incompatible with one-pot SO2F2-mediated alcohol activation and enables substitution of primary and secondary alcohols in 54-95% yield. Chiral secondary alcohols undergo a highly stereospecific (90-98% ee) double nucleophilic displacement with an overall retention of configuration.
Room temperature iron catalyzed transfer hydrogenation usingn-butanol and poly(methylhydrosiloxane)
Coles, Nathan T.,Linford-Wood, Thomas G.,Webster, Ruth L.
supporting information, p. 2703 - 2709 (2021/04/21)
Reduction of carbon-carbon double bonds is reported using a three-coordinate iron(ii) β-diketiminate pre-catalyst. The reaction is believed to proceedviaa formal transfer hydrogenation using poly(methylhydrosiloxane), PMHS, as the hydride donor and a bio-alcohol as the proton source. The reaction proceeds well usingn-butanol and ethanol, withn-butanol being used for substrate scoping studies. Allyl arene substrates, styrenes and aliphatic substrates all undergo reduction at room temperature. Unfortunately, clean transfer of a deuterium atom usingd-alcohol does not take place, indicating a complex catalytic mechanism. However, changing the deuterium source tod-aniline gives close to complete regioselectivity for mono-deuteration of the terminal position of the double bond. Finally, we demonstrate that efficient dehydrocoupling of alcohol and PMHS can be undertaken using the same pre-catalyst, giving high yields of H2within 30 minutes at room temperature.
Photoredox-Catalyzed Simultaneous Olefin Hydrogenation and Alcohol Oxidation over Crystalline Porous Polymeric Carbon Nitride
Qiu, Chuntian,Sun, Yangyang,Xu, Yangsen,Zhang, Bing,Zhang, Xu,Yu, Lei,Su, Chenliang
, p. 3344 - 3350 (2021/07/26)
Booming of photocatalytic water splitting technology (PWST) opens a new avenue for the sustainable synthesis of high-value-added hydrogenated and oxidized fine chemicals, in which the design of efficient semiconductors for the in-situ and synergistic utilization of photogenerated redox centers are key roles. Herein, a porous polymeric carbon nitride (PPCN) with a crystalline backbone was constructed for visible light-induced photocatalytic hydrogen generation by photoexcited electrons, followed by in-situ utilization for olefin hydrogenation. Simultaneously, various alcohols were selectively transformed to valuable aldehydes or ketones by photoexcited holes. The porosity of PPCN provided it with a large surface area and a short transfer path for photogenerated carriers from the bulk to the surface, and the crystalline structure facilitated photogenerated charge transfer and separation, thus enhancing the overall photocatalytic performance. High reactivity and selectivity, good functionality tolerance, and broad reaction scope were achieved by this concerted photocatalysis system. The results contribute to the development of highly efficient semiconductor photocatalysts and synergistic redox reaction systems based on PWST for high-value-added fine chemical production.