103668-33-3Relevant articles and documents
Selective hydrogenation of unsaturated carbonyls by Ni-Fe-based alloy catalysts
Putro, Wahyu S.,Kojima, Takashi,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
, p. 3637 - 3646 (2017)
Ni-Fe alloy catalysts prepared by a simple hydrothermal method and subsequent H2 treatment exhibited the greatest activity and selectivity for the hydrogenation of biomass-derived furfural to furfuryl alcohol among the examined second metals, such as Al, Ga, In, Co, and Ti. This work reveals that the alloying of Ni and Fe is a key factor in achieving highly selective hydrogenation of the CO moiety in unsaturated carbonyl substrates. We found that decreasing the temperature of H2 treatment (i.e. decreasing the crystallite size), e.g. Ni-Fe(2)HT-573 K (TOF = 952 h-1), increased the activity compared to that over Ni-Fe(2)HT-673 (TOF = 375 h-1) for furfural hydrogenation. This result suggests that a low-coordinated Ni-Fe alloy was imperative for the catalytic cycle. Moreover, the effect of the metal/support interface was critical; despite the high catalytic performance of Ni-Fe/TiO2, Ni-Fe/Al2O3, and Ni-Fe/CeO2, Ni-Fe supported on SiO2, taeniolite, and hydrotalcite catalysts were ineffective. Vibrational studies using FT-IR measurement confirmed that furfural was physically adsorbed on the surface of the Ni-Fe alloy catalyst via an η1(O) configuration. The synthetic scope of the Ni-Fe catalytic system was very broad; various types of unsaturated carbonyls, such as unsaturated aromatics, unconjugated aliphatics, and a large substituent, were selectively converted into the corresponding unsaturated alcohols.
Selective hydrogenation of furanic aldehydes using Ni nanoparticle catalysts capped with organic molecules
Jeong, Hojin,Kim, Chanyeon,Yang, Sungeun,Lee, Hyunjoo
, p. 609 - 615 (2016)
Ni nanoparticles were synthesized by a colloidal method in the presence of organic surface-capping agents and used to catalyze the selective hydrogenation of unsaturated furanic aldehydes to furanic alcohols. The effects of the Ni nanoparticle size and surface organic layer were evaluated. Of the 3.7, 5.1, 6.8, and 10.4 nm Ni nanoparticles tested in selective furfural (FFR) hydrogenation to furfuryl alcohol (FFA), the 6.8 nm Ni nanoparticles exhibited the highest yield because access to the surface sites on the smaller and larger nanoparticles was blocked by the densely packed organic layer and by their agglomeration due to magnetic attraction, respectively. The capped Ni nanoparticles exhibited a high FFA yield of 96%, whereas significant over-hydrogenation was observed when uncapped calcined Ni/SiO2 catalysts with similarly sized Ni nanoparticles were employed. Steric hindrance of the Ni surface induced by the organic surface layer led to selective FFR hydrogenation to FFA. The capped Ni nanoparticles could be reused repeatedly without a significant loss in the FFA yield. They also exhibited high selectivity (>90%) in the hydrogenation of other unsaturated furanic aldehydes to their corresponding alcohols.
Stereodirecting Effect of a Substrate Methoxy Substituent on the Addition of Singlet Methylene to a Double Bond
Young, Terry A.,O'Rourke, Colleen,Gray, Nathan B.,Lewis, Brian D.,Dvorak, Curt A.,et al.
, p. 6224 - 6228 (1993)
The stereodirecting effects of substrate methoxy, hydroxy, methylthio, and methyl substituents were examined in the addition of 1:CH2 to the double bonds of substrates 1a-d.The carbene, generated by photolysis of CH2N2, inserted into the C-H bonds of solvent and substrate, added to the substrate double bond to give products 2a-d, and attacked the oxygen or sulfur atom of substrates 1a-c to produce ylide intermediates which underwent 2,3-sigmatropic rearrangement to give products 3a-c.A preference for addition syn to the methoxy group of substrate 1a was observed when the reaction was run in pentane solution (syn-2a/anti-2a, 1.14 +/- 0.02), while a preference for formation of anti-2a was observed in diethyl ether solution (syn-2a/anti-2a, 0.92 +/- 0.03).A preference for 1:CH2 addition anti to the substrate substituent was observed for substrates 1b-d in both pentane and ether solution.The effect of the methoxy substituent was also examined in the addition of 1:CH2 to syn-7-methoxynorbornene (5b).Explanations for the substituent effects are offered based on both steric hindrance and interaction between 1:CH2 and the substituent, including formation and subsequent reaction of the ylide intermediates.
The non-heme diiron alkane monooxygenase of Pseudomonas oleovorans (AlkB) hydroxylates via a substrate radical intermediate [12]
Austin,Chang,Zylstra,Groves
, p. 11747 - 11748 (2000)
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Distal Alkenyl C-H Functionalization via the Palladium/Norbornene Cooperative Catalysis
Dong, Guangbin,Fatuzzo, Nina,Wu, Zhao
supporting information, p. 2715 - 2720 (2020/03/10)
A distal-selective alkenyl C-H arylation method is reported through a directed palladium/norbornene (Pd/NBE) cooperative catalysis. The key is to use an appropriate combination of the directing group and the NBE cocatalyst. A range of acyclic and cyclic c
Gold-Catalyzed Stereoselective Synthesis of Bicyclic Lactams and Ketones from N-Tosylynamidomethyl-Tethered Cyclohexenes
Zhong, Chang-Zhi,Tung, Po-Ting,Chao, Tsung-Han,Yeh, Ming-Chang P.
, p. 481 - 501 (2017/04/26)
Six-membered ring 3-enynamides underwent cycloisomerization in the presence of a catalytic amount of a gold(I) complex delivering mainly 4-azatricyclo[4.3.1.03,10]dec-2-ene derivatives and dibenz[cd,f]indole derivatives as the minor products under mild reaction conditions. Upon exposure to air, most aryl-substituted azatricycles led to bicyclic γ-lactams, while the ortho-tolyl- or alkyl-substituted azatricycles provided the corresponding bicyclic γ-lactams after oxidation with osmium tetraoxide and N-methylmorpholine-N-oxide. Under acidic conditions, the ortho-tolyl- or alkyl-substituted azatricycles were further transformed into 5-N-tosylaminomethyl-tethered bicyclo[4.2.0]octan-7-ones. The gold(I)-catalyzed tandem cycloisomerization/oxidation reaction also provided a new route for the synthesis of bridged bicyclic δ-lactams from six-membered ring 4-enynamides. The mild reaction conditions allowed the synthesis of a range of bicyclic γ- and δ-lactams and N-tosylaminomethyl-tethered bicyclo[4.2.0]octan-7-ones with high diastereoselectivities.
