100-80-1Relevant articles and documents
Excellent Selectivity with High Conversion in the Semihydrogenation of Alkynes using Palladium-Based Bimetallic Catalysts
Liu, Jian,Zhu, Yanan,Liu, Chang,Wang, Xiaoshi,Cao, Changyan,Song, Weiguo
, p. 4053 - 4057 (2017)
A series of active-carbon-supported PdPb and PdCu bimetal catalysts were prepared for the selective semihydrogenation of alkynes in the liquid phase. The Pd0.33Pb0.67/C catalyst showed the best performance for various alkynes under mild reaction conditions (room temperature and ambient H2 pressure) and achieved 100 % conversion with 98 % selectivity to alkenes. In particular, over-hydrogenation was avoided at complete alkyne conversion.
Homogeneous Unimolecular Pyrolysis Kinetics of o-, m-, and p-Methyl-2-phenylethyl Chlorides
Chuchani, Gabriel,Medina, Jose D.,Martin, Ignacio,Hernandez A, Jose A.
, p. 3900 - 3902 (1981)
The pyrolysis kinetics of isomeric methyl-2-phenylethyl chlorides have been studied in a static system over the pressure range of 56-240 torr and the temperature range of 419-470 deg C.These eliminations in seasoned vessels and in the presence of propene inhibitor are homogeneous and unimolecular, and follow a first-order rate law.The rate coefficients are given by the following Arrhenius equations: for 0-methyl-2-phenylethyl chloride, log k1 (s-1)=13.76+/-0.27)-(231.4+/-3.6) kJ mol-1 (2.303RT)-1; for m-methyl-2-phenylethyl chloride, log k1(s-1)=12.84+/-0.26)-(219.2+/-3.5) kJ mol-1 (2.303RT)-1; for p-methyl-2-phenylethyl chloride, log k1 (s-1)=(14.03+/-0.19)-(234.1+/-2.5) kJ mol-1 (2.303RT)-1.The electron release of the methyl substituent, at the three isomeric positions of the benzene ring, is very weak and does not reinforce the phenyl participation in rate enchancement relative to 2-phenylethyl chloride.
Tandem Diazotization Heck Reactions: A General Synthesis of Substituted Styrenes from Anilines
Beller, Matthias,Fischer, Hartmut,Kuehlein, Klaus
, p. 8773 - 8776 (1994)
The palladium-catalyzed olefination of different anilines with ethylene is shown to proceed generally in good yields.The substituted styrenes were obtained highly selective in a direct tandem diazotization Heck reaction at room temperature under atmospheric pressure of ethylene without concomitant side reaction to stilbenes.
Selective transfer semihydrogenation of alkynes with nanoporous gold catalysts
Wagh, Yogesh S.,Asao, Naoki
, p. 847 - 851 (2015)
A facile, highly chemo- and stereoselective transfer semihydrogenation of alkynes to Z-olefins has been achieved by use of unsupported nanoporous gold (AuNPore) as a heterogeneous catalyst together with formic acid as a hydrogen donor. A variety of terminal/internal and aromatic/aliphatic alkynes were reduced to the corresponding alkenes in high chemical yields with good functional-group tolerance. The catalyst is robust enough to be reused without leaching.
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Marvel et al.
, p. 736 (1946)
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Photoredox Catalyzed Sulfonylation of Multisubstituted Allenes with Ru(bpy)3Cl2 or Rhodamine B
Chen, Jingyun,Chen, Shufang,Jiang, Jun,Lu, Qianqian,Shi, Liyang,Xu, Zekun,Yimei, Zhao
supporting information, (2021/11/09)
A highly regio- and stereoselective sulfonylation of allenes was developed that provided direct access to α, β-substituted unsaturated sulfone. By means of visible-light photoredox catalysis, the free radicals produced by p-toluenesulfonic acid reacted with multisubstituted allenes to obtain Markovnikov-type vinyl sulfones with Ru(bpy)3Cl2 or Rhodamine B as photocatalyst. The yield of this reaction could reach up to 91%. A series of unsaturated sulfones would be used for further transformation to some valuable compounds.
Polymerization of Allenes by Using an Iron(II) β-Diketiminate Pre-Catalyst to Generate High Mn Polymers
Durand, Derek J.,Webster, Ruth L.,Woof, Callum R.
supporting information, p. 12335 - 12340 (2021/07/19)
Herein, we report an iron(II)-catalyzed polymerization of arylallenes. This reaction proceeds rapidly at room temperature in the presence of a hydride co-catalyst to generate polymers of weight up to Mn=189 000 Da. We have determined the polymer structure and chain length for a range of monomers through a combination of NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. Mechanistically, we postulate that the co-catalyst does not react to form an iron(II) hydride in situ, but instead the chain growth is proceeding via a reactive Fe(III) species. We have also performed kinetic and isotopic experiments to further our understanding. The formation of a highly unusual 1,3-substituted cyclobutane side-product is also investigated.
Vinyl Thianthrenium Tetrafluoroborate: A Practical and Versatile Vinylating Reagent Made from Ethylene
Juliá, Fabio,Paulus, Fritz,Ritter, Tobias,Yan, Jiyao
supporting information, p. 12992 - 12998 (2021/09/03)
The use of vinyl electrophiles in synthesis has been hampered by the lack of access to a suitable reagent that is practical and of appropriate reactivity. In this work we introduce a vinyl thianthrenium salt as an effective vinylating reagent. The bench-stable, crystalline reagent can be readily prepared from ethylene gas at atmospheric pressure in one step and is broadly useful in the annulation chemistry of (hetero)cycles, N-vinylation of heterocyclic compounds, and palladium-catalyzed cross-coupling reactions. The structural features of the thianthrene core enable a distinct synthesis and reactivity profile, unprecedented for other vinyl sulfonium derivatives.
