98-00-0Relevant articles and documents
Manganese-Catalyzed Hydrogenation of Sclareolide to Ambradiol
Zubar, Viktoriia,Lichtenberger, Niels,Schelwies, Mathias,Oeser, Thomas,Hashmi, A. Stephen K.,Schaub, Thomas
, (2021/11/16)
The hydrogenation of (+)-Sclareolide to (?)-ambradiol catalyzed by a manganese pincer complex is reported. The hydrogenation reaction is performed with an air- and moisture-stable manganese catalyst and proceeds under relatively mild reaction conditions at low manganese and base loadings. A range of other esters could be successfully hydrogenated leading to the corresponding alcohols in good to quantitative yields using this easy-to-make catalyst. A scale-up experiment was performed leading to 99.3 % of the isolated yield of (?)-Ambradiol.
Highly effective and chemoselective hydrodeoxygenation of aromatic alcohols
Han, Buxing,He, Mingyuan,Mei, Xuelei,Wu, Haihong,Wu, Wei,Xu, Caiyun,Zhai, Jianxin,Zhang, Kaili,Zhang, Zhanrong,Zheng, Bingxiao
, p. 1629 - 1635 (2022/02/21)
Effective hydrodeoxygenation (HDO) of aromatic alcohols is very attractive in both conventional organic synthesis and upgrading of biomass-derived molecules, but the selectivity of this reaction is usually low because of the competitive hydrogenation of the unsaturated aromatic ring and the hydroxyl group. The high activity of noble metal-based catalysts often leads to undesired side reactions (e.g., saturation of the aromatic ring) and excessive hydrogen consumption. Non-noble metal-based catalysts suffer from unsatisfied activity and selectivity and often require harsh reaction conditions. Herein, for the first time, we report chemoselective HDO of various aromatic alcohols with excellent selectivity, using porous carbon-nitrogen hybrid material-supported Co catalysts. The C-OH bonds were selectively cleaved while leaving the aromatic moiety intact, and in most cases the yields of targeted compounds reached above 99% and the catalyst could be readily recycled. Nitrogen doping on the carbon skeleton of the catalyst support (C-N matrix) significantly improved the yield of the targeted product. The presence of large pores and a high surface area also improved the catalyst efficiency. This work opens the way for efficient and selective HDO reactions of aromatic alcohols using non-noble metal catalysts.
Platinum thiolate complexes supported by PBP and POCOP pincer ligands as efficient catalysts for the hydrosilylation of carbonyl compounds
Chang, Jiarui,Chen, Xuenian,Xue, Man-Man,Zhang, Jie
supporting information, p. 2304 - 2312 (2022/02/21)
Diphosphino-boryl-based PBP pincer platinum thiolate complexes, [Pt(SR){B(NCH2PtBu2)2-1,2-C6H4}] (R = H, 1a; Ph, 1b), and benzene-based bisphosphinite POCOP pincer platinum thiolate complexes, [Pt(SR)(tBu2PO)2-1,3-C6H3] (R = H, 2a; Ph, 2b), were prepared
Solvent effect on the rate and direction of furfural transformations during hydrogenation over the Pd/C catalyst
Belskaya, O. B.,Likholobov, V. A.,Mironenko, R. M.
, p. 64 - 69 (2022/02/25)
The rate and directions of transformations during the liquid-phase hydrogenation of furfural with molecular hydrogen in the presence of the 5%Pd/C catalyst (at 423 K, 3 MPa) depend substantially on the chemical nature of the solvent. The main products of
High-Temperature Synthesis of Carbon-Supported Bimetallic Nanocluster Catalysts by Enlarging the Interparticle Distance
Zuo, Lu-Jie,Xu, Shi-Long,Wang, Ao,Yin, Peng,Zhao, Shuai,Liang, Hai-Wei
supporting information, p. 2719 - 2723 (2022/02/16)
Supported bimetallic nanoparticle catalysts with small size have attracted wide research attention in catalysis but are difficult to synthesize because high-temperature annealing required for alloying inevitably accelerates metal sintering and leads to larger particles. Here, we report a simple and scalable critical interparticle distance method for the synthesis of a family of bimetallic nanocluster catalysts with an average particle size of only 1.5 nm by using large-surface-area carbon black supports at high temperatures, which consist of 12 diverse combinations of 3 noble metals (Pt, Ru, and Rh) and 4 other metals (Cr, Fe, Zr, and Sn). In this strategy, high-temperature treatments ensure the formation of alloyed bimetallic nanoparticles and enlargement of the interparticle distance on high-surface-area supports significantly suppresses metal sintering. The prepared ultrafine Pt2Sn and RuSn nanocluster catalysts exhibited enhanced performance in catalyzing the synthesis of aromatic secondary amines and the selective hydrogenation of furfural, respectively.
PNO ligand containing planar chiral ferrocene and application thereof
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Paragraph 0114-0118, (2021/06/21)
The invention discloses a PNO ligand containing planar chiral ferrocene and application thereof. The PNO ligand containing planar chiral ferrocene is a planar chiral ferrocene-containing and phenol-containing PNO ligand as shown in a general formula (I) or (II) which is described in the specification, or a planar chiral ferrocene-containing and aryl-phosphoric-acid-containingPNO ligand containing as shown in a general formula (III) or (IV) which is described in the specification, or a planar chiral ferrocene-containing and carbon-chiral-phenol-containingPNO ligand as shown in a general formula (V) or (VI) which is described in the specification. The invention provides tridentate PNO ligands and processes for their complexation with transition metal salts or transition metal complexes; the introduction of salicylaldehyde and derivatives thereof, which are simple and easy to obtain, enables the ligands to have a bifunctionalization effect, and -OH in a formed catalyst has stronger acidity and is beneficial to combination with N/O in polar double bonds. Therefore, due to the bifunctionalization effect of the catalyst, the interaction between the catalyst and a substrate can be greatly improved, so a reaction can obtain higher catalytic activity and stereoselectivity.
A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
supporting information, p. 16865 - 16873 (2021/10/20)
Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
Biocatalytic transformation of furfural into furfuryl alcohol using resting cells of Bacillus cereus
Rodríguez M, Alejandra,Rache, Leidy Y.,Brijaldo, María H.,Romanelli, Gustavo P.,Luque, Rafael,Martinez, José J.
, p. 220 - 225 (2021/02/16)
The bioconversion of furfural to furfuryl alcohol is an attractive route in biomass valorization that could replace traditional contaminant methods. The use of whole cells has been explored for this purpose. Bacillus cereus without previous treatment with furanic compounds was used to selectively obtain furfuryl alcohol. Growing and resting cells were employed. Using growing cells of B. cereus, lower yields to alcohol were obtained because of furfural toxicity. However, employing resting cells it was possible to reach higher yields to furfuryl alcohol. Optimal operative conditions were studied: different concentrations of furfural, glucose and molybdenum, pH, and temperature. Thus, glucose (100 mM) and molybdenum (0.1 mM) were added to maintain cell biomass obtaining a yield to furfuryl alcohol close to 80% at 30 °C, pH 7.2 from 30 mM of furfural.
Valorization of furfural using ruthenium (II) complexes containing phosphorus-nitrogen ligands under homogeneous transfer hydrogen condition
Aguirre, Pedro,Aranda, Braulio,López, Vicente,Moya, Sergio A.,Parra-Melipán, Sebastián,Valdebenito, Gonzalo
, (2021/08/10)
In this paper, we report the catalytic activity of a series of ruthenium (II) complexes containing phosphorus-nitrogen bidentated (P-N) ligands in the hydrogenation of furfural via hydrogen transfer reaction using two hydrogen donor sources: 2-propanol in basic medium and formic acid under mild conditions. The results showed that all the ruthenium complexes studied are catalytically active in the hydrogenation of furfural by hydrogen transfer reaction; they showed 100% conversion with both hydrogen sources. However, selectivities towards the formation of furfuryl alcohol were better when formic acid was used. It was also found that the reaction studied in a basic medium competes with the Cannizzaro reaction, obtaining furfuryl alcohol and furoic acid in a 70/30 ratio; on the other hand, using formic acid as the hydrogen source yields furfuryl alcohol with 100% selectivity. Although formic acid can be used as a hydrogen source successfully. The optimal substrate/acid ratio was found to be 1:1, as a higher concentration of formic acid can cause catalyst decomposition. The yielded products, furfuryl alcohol and furoic acid, obtained from renewable sources, have multiple applications in the organic chemical industry, replacing or complementing similar fossil-derived products.
