4407-36-7Relevant articles and documents
Microwave-assisted syntheses of 1,2-diketones
Mitra, Alok Kumar,De, Aparna,Karchaudhuri, Nilay
, p. 246 - 247 (1999)
A comparative study of the conversion of a number of α-hydroxyketones into 1,2-diketones by three oxidants under microwave irradiation is reported.
-
Harris,Weale
, p. 953,955 (1956)
-
Unique Regio- and Stereoselectivity in Pd-Catalyzed Chlorocarbonylation Reaction of 2-Phenylethynyl Selenides and 2-Alkylethynyl Selenides. Highly Stereoselective Synthesis of 2-Seleno-3-chloroacrylates
Huang, Xian,Sun, Aiming
, p. 6561 - 6565 (2000)
Regio- and stereoselectivity in the chloropalladation carbonylation reaction of different acetylenic selenides in the presence of 0.05 equiv of PdCl2 and 3 equiv of cupric chloride under 1 atm of carbon monoxide affording 2-seleno-3-chloroacrylates were investigated. Opposite stereoselectivities were observed with 2-phenylethynyl selenides and 2-alkylethynyl selenides: the reactions of 2-phenylethynyl selenides afforded (E)-2-seleno-3-chloro-3-phenylacrylates, while the reactions of 2-alkylethynyl selenides gave (Z)-2-seleno-3-chloro-3-alkylacrylates. A chloropalladation carbonylation mechanism for this reaction was proposed. The regio- and stereoselective chloropalladation of the carbon-carbon triple bond in acetylenic selenides affords 1-enylpalladium intermediates, in which the palladium atom connects with the carbon atom bonding with the selenium atom. Carbonylation in the presence of an alcohol affords 2-seleno-3-chloroacrylates.
Trimerisation of the cationic fragments [(eta ring)M(Aa)]+ (where eta ring)M=eta 5 pentamethylcyclopentadienyl rhodium, eta 5 pentamethylcyclopentadienyl iridium, or eta 6 4isopropyltolyl ruthenium and Aa = alpha amino acidate) with chiral self-recognition: Synthesis, characterisation, solution studies and catalytic reactions of the trimers tris[eta ring M(Aa)] tris(tetrafluoroborate)
Carmona, Daniel,Lahoz, Fernando J.,Atencio, Reinaldo,Oro, Luis A.,Lamata, M. Pilar,Viguri, Fernando,San Jose, Emilio,Vega, Cristina,Reyes, Josefa,Joo, Ferenc,Katho, Agnes
, p. 1544 - 1564 (1999)
The mononuclear neutral chlorides [(η-ring)M(Aa)Cl] ((η-ring)-M- (η5-C5Me5)Rh, (η5-C5Me5)Ir, (η6-p-MeC6H4iPr)Ru; Aa = α-amino acidate) were treated with AgBF4 to yield the corresponding new chiral trimers [{(η-ring)M(Aa)}3](BF4)3. Compounds [{(η5- C5Me5)Ir(Ala)}3](BF4)3 (1b) and [{(η6-p-MeC6H4iPr)Ru(L- Pro)}3](BF4)3 (6c) were characterised by X-ray diffraction. Trimerisation takes place by chiral self-recognition: the trimers R(M)R(M)R(M) (ρ isomer) or S(M)S(M)S(M) (σ isomer), which have equal configuration at the metal centre, were the only diastereomers detected. In solution, a diastereomerisation process between both isomers occurs, where the equilibrium constant depends on the solvent, amino acidate, and metal. The different localisation of the polar groups (NH or NH2 moieties) on the molecular surface of the two diastereomers (ρ and σ) provides a qualitative explanation for the different diastereomer stability observed in solution. The new chiral trimers catalyse the reduction of unsaturated aldehydes to unsaturated alcohols by hydrogen transfer from aqueous sodium formate and the reduction of acetophenone by hydrogen transfer from 2-propanol with up to 75 % ee.
Oxoammonium-Mediated Allylsilane–Ether Coupling Reaction
Carlet, Federica,Bertarini, Greta,Broggini, Gianluigi,Pradal, Alexandre,Poli, Giovanni
supporting information, p. 2162 - 2168 (2021/04/02)
A new C(sp3)?H functionalization reaction consisting of the oxidative α-allylation of allyl- and benzyl- methyl ethers has been developed. The C?C coupling could be carried out under mild conditions thanks to the use of cheap and green oxoammonium salts. The scope of the reaction was studied over 27 examples, considering the nature of the substituents on the two coupling partners.
Differentiation of Pt?Fe and Pt?Ni3 Surface Catalytic Mechanisms towards Contrasting Products in Chemoselective Hydrogenation of α,β-Unsaturated Aldehydes
Ning, Liangmin,Zhang, Mingtao,Liao, Shengyun,Zhang, Yuting,Jia, Dandan,Yan, Yunfang,Gu, Wen,Liu, Xin
, p. 704 - 711 (2020/12/07)
Noble-metal catalysts serve as an irreplaceable role in pharmaceutical, perfume and fine chemicals fields. However, there still remains a grand challenge in controlling chemoselectivity. Herein, we have synthesized a bimetallic nanostructure supported on porous metal-organic frameworks (Pt?Fe/UiO-66, Pt-Ni3/UiO-66), in which Pt nanoparticles was modified with non-noble metal (Fe or Ni) directly. The as-synthesized catalysts can function as a switch for selective hydrogenation of α,β-unsaturated aldehydes to afford the potential products on-demand. In comparison with the conventional Pt-based catalysts, Pt?Fe/UiO-66 and Pt-Ni3/UiO-66 catalysts exhibit excellently catalytic activity, enhanced selectivity and improved stability for selectivity hydrogenation. The partial charge reconfiguration and electronic coupling effect existing in such distinctive bicomponent nanocatalysts was confirmed by some comprehensive characterization and density functional theory (DFT) calculations. The developed method for precisely modification the composition and interaction between the noble metal and non-noble metal provides a feasible avenue to design the advanced catalysts.
Platinum Nanosheets Intercalated into Natural and Artificial Graphite Powders
Shirai, Masayuki,Kubo, Kohei,Sodeno, Mika,Nanao, Hidetaka
, p. 2035 - 2040 (2021/06/25)
Insertion of sheet-type platinum particles (platinum nanosheets) between graphite layers was achieved by a thermal treatment of a mixture of platinum chloride (IV) and graphite powder (natural graphite or artificial graphite) under 0.3 MPa of chlorine at 723 K, followed by the treatment under 40 kPa of hydrogen pressure. Similar platinum nanosheets, which were 1–3 nm in thickness and 100–500 nm in width and had a number of hexagonal holes and edges with 120° angle, were formed between the layers of both natural graphite or artificial graphite; however, their location in the graphite layers depended on the type of graphite used. A number of platinum nanosheets were observed in the edge region of natural graphite particles which have flat surface. On the other hand, a number of platinum nanosheets were found inside and away from the edge of the artificial graphite particles especially in the vicinity of the cracks. Both the platinum nanosheet-containing artificial and natural graphite samples showed high selectivity to cinnamyl alcohol in cinnamaldehyde hydrogenation under supercritical carbon dioxide conditions, while spherical platinum particles, which were located on the surface of natural and artificial graphite, showed lower selectivity.
