4410-75-7Relevant articles and documents
Sustainable System for Hydrogenation Exploiting Energy Derived from Solar Light
Ishida, Naoki,Kamae, Yoshiki,Ishizu, Keigo,Kamino, Yuka,Naruse, Hiroshi,Murakami, Masahiro
supporting information, p. 2217 - 2220 (2021/02/16)
Herein described is a sustainable system for hydrogenation that uses solar light as the ultimate source of energy. The system consists of two steps. Solar energy is captured and chemically stored in the first step; exposure of a solution of azaxanthone in ethanol to solar light causes an energy storing dimerization of the ketone to produce a sterically strained 1,2-diol. In the second step, the chemical energy stored in the vicinal diol is released and used for hydrogenation; the diol offers hydrogen onto alkenes and splits back to azaxanthone, which is easily recovered and reused repeatedly for capturing solar energy.
Towards the Circular Economy: Converting Aromatic Plastic Waste Back to Arenes over a Ru/Nb2O5 Catalyst
Jing, Yaxuan,Wang, Yanqin,Furukawa, Shinya,Xia, Jie,Sun, Chengyang,Hülsey, Max J.,Wang, Haifeng,Guo, Yong,Liu, Xiaohui,Yan, Ning
supporting information, p. 5527 - 5535 (2021/02/05)
The upgrading of plastic waste is one of the grand challenges for the 21st century owing to its disruptive impact on the environment. Here, we show the first example of the upgrading of various aromatic plastic wastes with C?O and/or C?C linkages to arenes (75–85 % yield) via catalytic hydrogenolysis over a Ru/Nb2O5 catalyst. This catalyst not only allows the selective conversion of single-component aromatic plastic, and more importantly, enables the simultaneous conversion of a mixture of aromatic plastic to arenes. The excellent performance is attributed to unique features including: (1) the small sized Ru clusters on Nb2O5, which prevent the adsorption of aromatic ring and its hydrogenation; (2) the strong oxygen affinity of NbOx species for C?O bond activation and Br?nsted acid sites for C?C bond activation. This study offers a catalytic path to integrate aromatic plastic waste back into the supply chain of plastic production under the context of circular economy.
Nickel-catalyzed reductive deoxygenation of diverse C-O bond-bearing functional groups
Cook, Adam,MacLean, Haydn,St. Onge, Piers,Newman, Stephen G.
, p. 13337 - 13347 (2021/11/20)
We report a catalytic method for the direct deoxygenation of various C-O bond-containing functional groups. Using a Ni(II) pre-catalyst and silane reducing agent, alcohols, epoxides, and ethers are reduced to the corresponding alkane. Unsaturated species including aldehydes and ketones are also deoxygenated via initial formation of an intermediate silylated alcohol. The reaction is chemoselective for C(sp3)-O bonds, leaving amines, anilines, aryl ethers, alkenes, and nitrogen-containing heterocycles untouched. Applications toward catalytic deuteration, benzyl ether deprotection, and the valorization of biomass-derived feedstocks demonstrate some of the practical aspects of this methodology.
Metal-Organic Framework-Confined Single-Site Base-Metal Catalyst for Chemoselective Hydrodeoxygenation of Carbonyls and Alcohols
Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Manna, Kuntal
supporting information, p. 9029 - 9039 (2021/06/28)
Chemoselective deoxygenation of carbonyls and alcohols using hydrogen by heterogeneous base-metal catalysts is crucial for the sustainable production of fine chemicals and biofuels. We report an aluminum metal-organic framework (DUT-5) node support cobalt(II) hydride, which is a highly chemoselective and recyclable heterogeneous catalyst for deoxygenation of a range of aromatic and aliphatic ketones, aldehydes, and primary and secondary alcohols, including biomass-derived substrates under 1 bar H2. The single-site cobalt catalyst (DUT-5-CoH) was easily prepared by postsynthetic metalation of the secondary building units (SBUs) of DUT-5 with CoCl2 followed by the reaction of NaEt3BH. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy (XANES) indicated the presence of CoII and AlIII centers in DUT-5-CoH and DUT-5-Co after catalysis. The coordination environment of the cobalt center of DUT-5-Co before and after catalysis was established by extended X-ray fine structure spectroscopy (EXAFS) and density functional theory. The kinetic and computational data suggest reversible carbonyl coordination to cobalt preceding the turnover-limiting step, which involves 1,2-insertion of the coordinated carbonyl into the cobalt-hydride bond. The unique coordination environment of the cobalt ion ligated by oxo-nodes within the porous framework and the rate independency on the pressure of H2 allow the deoxygenation reactions chemoselectively under ambient hydrogen pressure.
Raney nickel-catalyzed hydrodeoxygenation and dearomatization under transfer hydrogenation conditions—Reaction pathways of non-phenolic compounds
Philippov,Chibiryaev,Martyanov
, p. 35 - 42 (2019/05/27)
Catalytic reduction of oxygen-containing aromatic compounds has been studied under transfer hydrogenation (TH) conditions at 150 °C in 2-PrOH as a hydrogen donor. Raney nickel is used as a heterogeneous catalyst. The reaction of aromatic non-phenolic carbonyl compounds is most likely to proceed through the pathway “aromatic ketone (aldehyde)→aromatic alcohol→alkylaromatics→saturated alkylcyclohexane”. One of the main reactions under the TH conditions is a hydrodeoxygenation (HDO) process. Unexpectedly, the hydrodeoxygenation of aromatic ketones to alkylaromatics (C[dbnd]O → CH2) occurs faster than of corresponding aromatic alcohols (HC–OH → CH2) that means either additional reaction pathway of its hydrodeoxygenation missing for the corresponding aromatic alcohols or specific interaction of OH functionality with Raney nickel surface obstructing (hindering) the further reduction. Benzaldehyde is shown to be less reactive than the aromatic ketones under the same reaction conditions. The main reason is proposed to be carbon monoxide release resulted from the decarbonylation of the aldehyde. Carbon monoxide demonstrates a poisoning effect on Raney nickel surface that is evidenced in the catalyzed TH reaction of acetophenone. The HDO reaction of anisole under the same reaction conditions was a little slowly than of oxygen-containing non-phenolic aromatics.
Breaking the Limit of Lignin Monomer Production via Cleavage of Interunit Carbon–Carbon Linkages
Dong, Lin,Lin, Longfei,Han, Xue,Si, Xiaoqin,Liu, Xiaohui,Guo, Yong,Lu, Fang,Rudi?, Svemir,Parker, Stewart F.,Yang, Sihai,Wang, Yanqin
, p. 1521 - 1536 (2019/06/14)
Conversion of lignin into monocyclic hydrocarbons as commodity chemicals and drop-in fuels is a highly desirable target for biorefineries. However, this is severely hindered by the presence of stable interunit carbon–carbon linkages in native lignin and those formed during lignin extraction. Herein, we report a new multifunctional catalyst, Ru/NbOPO4, that achieves the first example of catalytic cleavage of both interunit C–C and C–O bonds in one-pot lignin conversions to yield 124%–153% of monocyclic hydrocarbons, which is 1.2–1.5 times the yields obtained from the established nitrobenzene oxidation method. This catalyst also exhibits high stability and selectivity (up to 68%) to monocyclic arenes over repeated cycles. The mechanism of the activation and cleavage of 5–5 C–C bonds in biphenyl, as a lignin model adopting the most robust C–C linkages, has been revealed via in situ inelastic neutron scattering coupled with modeling. This study breaks the conventional theoretical limit on lignin monomer production. The conversion of lignin into monocyclic hydrocarbons as commodity chemicals and drop-in fuels is essential for the future of biorefineries. State-of-the-art lignin depolymerization is primarily achieved via cleavage of interunit C–O bonds to form low-molecular-weight feedstocks. However, these processes can hardly cleave interunit C–C bonds in lignin, and thus, the yields of lignin monomers are heavily restricted. Here, we report a multifunctional catalyst, Ru/NbOPO4, that achieves the first example of catalytic cleavage of both interunit C–C and C–O bonds in lignin in one-pot reactions to yield 153% of monocyclic C6–C9 hydrocarbons from Kraft lignin, which is 1.5 times the theoretical yield obtained from the established nitrobenzene oxidation (NBO) method. Thus, significantly, this study successfully breaks the conventional limit on lignin monomer production. Lignin, containing a large volume of aromatic functionalities, is the most energy-dense fraction of renewable biomass. Particularly, conversion of lignin into monocyclic hydrocarbons as commodity chemicals is a highly desirable target. However, this is severally hindered by the presence of stable interunit carbon–carbon linkages in native lignin and those formed during lignin extraction. Here, we report a multifunctional Ru/NbOPO4 catalyst that achieves the first example of catalytic cleavage of both interunit C–C and C–O bonds in lignin in one-pot reactions.
Carbonyl and olefin hydrosilylation mediated by an air-stable phosphorus(iii) dication under mild conditions
Andrews, Ryan J.,Chitnis, Saurabh S.,Stephan, Douglas W.
supporting information, p. 5599 - 5602 (2019/05/21)
The readily-accessible, air-stable Lewis acid [(terpy)PPh][B(C6F5)4]21 is shown to mediate the hydrosilylation of aldehydes, ketones, and olefins. The utility and mechanism of these hydrosilylations are considered.
Mild and efficient rhodium-catalyzed deoxygenation of ketones to alkanes
Argouarch, Gilles
supporting information, p. 11041 - 11044 (2019/07/31)
A new and simple method for the deoxygenation of ketones to alkanes is presented. Most substrates are reduced under mild conditions by triethylsilane in the presence of catalytic amounts of [Rh(μ-Cl)(CO)2]2. This system selectively provides the methylene hydrocarbons in good to excellent yields starting from acetophenones and diaryl ketones. A rapid examination of the reaction pathway suggests that the ketone is first converted into an alcohol, which then undergoes hydrogenolysis to give the alkane.
Cobalt-Nanoparticles Catalyzed Efficient and Selective Hydrogenation of Aromatic Hydrocarbons
Murugesan, Kathiravan,Senthamarai, Thirusangumurugan,Alshammari, Ahmad S.,Altamimi, Rashid M.,Kreyenschulte, Carsten,Pohl, Marga-Martina,Lund, Henrik,Jagadeesh, Rajenahally V.,Beller, Matthias
, p. 8581 - 8591 (2019/09/12)
The development of inexpensive and practical catalysts for arene hydrogenations is key for future valorizations of this general feedstock. Here, we report the development of cobalt nanoparticles supported on silica as selective and general catalysts for such reactions. The specific nanoparticles were prepared by assembling cobalt-pyromellitic acid-piperazine coordination polymer on commercial silica and subsequent pyrolysis. Applying the optimal nanocatalyst, industrial bulk, substituted, and functionalized arenes as well as polycyclic aromatic hydrocarbons are selectively hydrogenated to obtain cyclohexane-based compounds under industrially viable and scalable conditions. The applicability of this hydrogenation methodology is presented for the storage of H2 in liquid organic hydrogen carriers.
