39952-67-5Relevant academic research and scientific papers
Ruthenium-Catalyzed Dehydrogenation Through an Intermolecular Hydrogen Atom Transfer Mechanism
Huang, Lin,Bismuto, Alessandro,Rath, Simon A.,Trapp, Nils,Morandi, Bill
supporting information, p. 7290 - 7296 (2021/03/01)
The direct dehydrogenation of alkanes is among the most efficient ways to access valuable alkene products. Although several catalysts have been designed to promote this transformation, they have unfortunately found limited applications in fine chemical synthesis. Here, we report a conceptually novel strategy for the catalytic, intermolecular dehydrogenation of alkanes using a ruthenium catalyst. The combination of a redox-active ligand and a sterically hindered aryl radical intermediate has unleashed this novel strategy. Importantly, mechanistic investigations have been performed to provide a conceptual framework for the further development of this new catalytic dehydrogenation system.
Asymmetric Hydrogenation of Unfunctionalized Tetrasubstituted Acyclic Olefins
Bachmann, Stephan,Bigler, Raphael,Denmark, Scott E.,Gosselin, Francis,Han, Chong,Hildbrand, Stefan,Mack, Kyle A.,Pfaltz, Andreas,Scalone, Michelangelo,Shen, Jeff,Tosatti, Paolo,Zhang, Haiming
supporting information, p. 2844 - 2849 (2020/02/05)
Asymmetric hydrogenation has evolved as one of the most powerful tools to construct stereocenters. However, the asymmetric hydrogenation of unfunctionalized tetrasubstituted acyclic olefins remains the pinnacle of asymmetric synthesis and an unsolved challenge. We report herein the discovery of an iridium catalyst for the first, generally applicable, highly enantio- and diastereoselective hydrogenation of such olefins and the mechanistic insights of the reaction. The power of this chemistry is demonstrated by the successful hydrogenation of a wide variety of electronically and sterically diverse olefins in excellent yield and high enantio- and diastereoselectivity.
Cathodic reductive couplings and hydrogenations of alkenes and alkynes catalyzed by the B12 model complex
Shimakoshi, Hisashi,Luo, Zhongli,Tomita, Kazuya,Hisaeda, Yoshio
, p. 71 - 77 (2017/05/08)
The reductive coupling and hydrogenation of alkenes were catalyzed by the B12 model complex, heptamethyl cobyrinate perchlorate (1), in the presence of acid during electrolysis at??0.7?V vs. Ag/AgCl in acetonitrile. Conjugated alkenes showed a good reactivity during electrolysis to form reduced products. The product distributions were dependent on the substituents at the C[dbnd]C bond of the alkenes. ESR spin-trapping experiments using 5,5-dimethylpyrroline N-oxide (DMPO) revealed that the cobalt-hydrogen complex (Co–H complex) should be formed during the electrolysis and it functioned as an intermediate for the alkene reduction. The electrolysis was also applied to an alkyne, such as phenylacetylene, to form 2,3-diphenylbutane (racemic and meso) and ethylbenzene via styrene as reductive coupling and hydrogenated products, respectively.
Organomolybdenum and Organotungsten Reagents, V. - On the Additive, Reductive Carbonyl Dimerization (ARCD Reaction)
Kauffmann, Thomas,Jordan, Jan,Voss, Karl-Uwe,Wilde, Heinz-Wilhelm
, p. 2083 - 2092 (2007/10/02)
Reagents of the type R4(PrO)4(μ-PrO)2W2 (3; R = Me, Et, Pr, Bu, sBu, iBu, Hex, Me3SiCH2, Ph) prepared in situ by the action of organolithium or Grignard compounds on (PrO)4(μ-PrO)2W2Cl4 (2), react with aromatic aldehydes or ketones and with the α,β-unsaturated ketone benzylidene acetone in a novel reaction, called the ARCD reaction, to give products 4 of the type RR'R''C-CRR'R'' with mostly good yields.In the case of benzylidene acetone and furfural besides the ARCD products the rearranged products 27 and 29 are formed.With the reagent Ph4(PrO)4(μ-PrO)2W2 (3b) ARCD reactions are also possible in moderate yields with aliphatic aldehydes and ketones.The more closely investigated reagent Me4(PrO)4(μ-PrO)2W2 (3a; decomposition at about -45 deg C) tolerates the aromatic bound functional groups Cl, F, OH, OMe, and NMe2 in the substrates, but not the NO2 and CO2Et substituents.It reacts with PhCOX (X = OEt, Cl, OCOPh) via acetophenone to give PhCMe2-CMe2Ph. - For the ARCD reactions a radical mechanism (Scheme 7) is postulated. - Key Words: Tungsten complexes/ Carbonyl dimerization
SILVER(I)/ PERSULFATE OXIDATIVE DECARBOXYLATION OF CARBOXYLIC ACIDS. ARYLACETIC ACID DIMERIZATION.
Fristad, William E.,Klang, Jeffrey A.
, p. 2219 - 2222 (2007/10/02)
The oxidative decarboxylation of arylacetic acids by sodium persulfate and a catalytic amount of silver nitrate produces benzylic radicals which dimerize cleanly to give 1,2-diarylethanes.
