1077-16-3Relevant articles and documents
Copper-catalyzed semihydrogenation of alkynes to Z -alkenes
Semba, Kazuhiko,Kameyama, Ryohei,Nakao, Yoshiaki
, p. 318 - 322 (2015)
Copper-catalyzed semihydrogenation of internal alkynes has been developed. The reaction proceeds under an atmosphere of hydrogen (5 atm) at 100 °C in the presence of a readily available [(PPh3)CuCl]4 catalyst to give various Z-alkenes stereoselectively.
Isolated Organometallic Nickel(III) and Nickel(IV) Complexes Relevant to Carbon-Carbon Bond Formation Reactions
Schultz, Jason W.,Fuchigami, Kei,Zheng, Bo,Rath, Nigam P.,Mirica, Liviu M.
, p. 12928 - 12934 (2016)
Nickel-catalyzed cross-coupling reactions are experiencing a dramatic resurgence in recent years given their ability to employ a wider range of electrophiles as well as promote stereospecific or stereoselective transformations. In contrast to the extensively studied Pd catalysts that generally employ diamagnetic intermediates, Ni systems can more easily access various oxidation states including odd-electron configurations. For example, organometallic NiIII intermediates with aryl and/or alkyl ligands are commonly proposed as the active intermediates in cross-coupling reactions. Herein, we report the first isolated NiIII-dialkyl complex and show that this species is involved in stoichiometric and catalytic C-C bond formation reactions. Interestingly, the rate of C-C bond formation from a NiIII center is enhanced in the presence of an oxidant, suggesting the involvement of transient NiIV species. Indeed, such a NiIV species was observed and characterized spectroscopically for a nickelacycle system. Overall, these studies suggest that both NiIII and NiIV species could play an important role in a range of Ni-catalyzed cross-coupling reactions, especially those involving alkyl substrates.
Efficient synthesis of amylbenzenes over zeolite catalysts
Zhang, Huanyan,Liu, Yueming,Wu, Haihong,Jiang, Yongwen,He, Mingyuan,Wu, Peng
, p. 138 - 139 (2007)
The liquid-phase heterogeneous alkylation of benzene with 2-methyl-2-butene takes place actively and selectively over large-pore zeolite catalysts, which implies an environmentally friendly route for the synthesis of fert-amylbenzene. Copyright
Relevance of Single-Transmetalated Resting States in Iron-Mediated Cross-Couplings: Unexpected Role of σ-Donating Additives
Rousseau, Lidie,Touati, Nadia,Binet, Laurent,Thuéry, Pierre,Lefèvre, Guillaume
, p. 7991 - 7997 (2021)
Control of the transmetalation degree of organoiron(II) species is a critical parameter in numerous Fe-catalyzed cross-couplings to ensure the success of the process. In this report, we however demonstrate that the selective formation of a monotransmetalated FeII species during the catalytic regime counterintuitively does not alone ensure an efficient suppression of the nucleophile homocoupling side reaction. It is conversely shown that a fine control of the transmetalation degree of the transient FeIII intermediates obtained after the activation of alkyl electrophiles by a single-electron transfer (SET), achievable using σ-donating additives, accounts for the selectivity of the cross-coupling pathway. This report shows for the first time that both coordination spheres of FeII resting states and FeIII short-lived intermediates must be efficiently tuned during the catalytic regime to ensure high coupling selectivities.
N-Hexane activation over zeolites: Aromatic alkylation to 1-phenylhexane
Danilina, Nadiya,Payrer, Elisabeth L.,Van Bokhoven, Jeroen A.
, p. 1509 - 1510 (2010)
Terminal 1-phenylhexane was observed during alkylation of benzene with n-hexane over 10-membered ring zeolites at moderate temperature, whereas it was not observed when 1-hexene was the reactant. The Royal Society of Chemistry 2010.
Nanocage catalysts - Rhodium nanoclusters encapsulated with dendrimers as accessible and stable catalysts for olefin and nitroarene hydrogenations
Nakamula, Ikuse,Yamanoi, Yoshinori,Yonezawa, Tetsu,Imaoka, Takane,Yamamoto, Kimihisa,Nishihara, Hiroshi
, p. 5716 - 5718 (2008)
The phenylazomethine dendrimer generation 4 (TPP-DPA G4) and polyamidoamine dendrimer (PAMAM G4-OH) encapsulating rhodium nanocluster were found to be highly effective for olefin and nitroarene hydrogenations, affording high TOF (up to 17520 h-1); the important feature of the nanocage catalyst is that substrates can pass through the branches of the protecting groups of nanoclusters without releasing nanoclusters from the dendrimer. The Royal Society of Chemistry.
Arylation of hydrocarbons enabled by organosilicon reagents and weakly coordinating anions
Shao, Brian,Bagdasarian, Alex L.,Popov, Stasik,Nelson, Hosea M.
, (2017)
Over the past 80 years, phenyl cation intermediates have been implicated in a variety of C-H arylation reactions. Although these examples have inspired several theoretical and mechanistic studies, aryl cation equivalents have received limited attention in organic methodology. Their high-energy, promiscuous reactivity profiles have hampered applications in selective intermolecular processes. We report a reaction design that overcomes these challenges. Specifically, we found that b-silicon-stabilized aryl cation equivalents, generated via silylium-mediated fluoride activation, undergo insertion into sp3 and sp2 C-H bonds. This reaction manifold provides a framework for the catalytic arylation of hydrocarbons, including simple alkanes such as methane. This process uses low loadings of Earth-abundant initiators (1 to 5 mole percent) and occurs under mild conditions (30° to 100°C).
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Denissenko
, (1937)
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Dietrich et al.
, p. 153 (1968)
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Moore,W.M.,Peters,D.G.
, p. 453 - 456 (1972)
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Organolithium additions to styrene are synthetically viable
Wei, Xudong,Taylor, Richard J. K.
, p. 187 - 188 (1996)
In diethyl ether at -78 to -25°C, styrene undergoes efficient addition reactions with a range of alkyllithium reagents, and the intermediate benzyllithiums can be trapped (e.g. with carbon dioxide and chlorotrimethylsilane); two aryl-substituted styrenes are shown to react in a similar manner.
Regioselective Hydroalkylation of Vinylarenes by Cooperative Cu and Ni Catalysis
Ravn, Anne K.,Johansen, Martin B.,Skrydstrup, Troels
supporting information, (2021/12/14)
Disclosed here is a dual copper and nickel catalytic system with a silyl hydride source for promoting the linear selective hydroalkylation of vinylarenes. This carbon–carbon bond-forming protocol is applied to couple a variety of functionalized vinylarenes with alkyl halides applying a nickel(II) NNN pincer complex in the presence of an NHC-ligated copper catalyst. This combination allows for a 1 mol % loading of the nickel catalyst leading to turnover numbers of up to 72. Over 40 examples are presented, including applications for pharmaceutical diversification. Labeling experiments demonstrated the regioselectivity of the reaction and revealed that the copper catalyst plays a crucial role in enhancing the rate for formation of the reactive linear alkyl nickel complex. Overall, the presented work provides a complimentary approach for hydroalkylation reactions, whilst providing a preliminary mechanistic understanding of the cooperativity between the copper and nickel complexes.
Visible-Light-Induced Nickel-Catalyzed Cross-Coupling with Alkylzirconocenes from Unactivated Alkenes
Bai, Songlin,Gao, Yadong,Jiang, Chao,Liu, Xiaolei,Qi, Xiangbing,Wang, Jing,Wu, Qingcui,Yang, Chao
supporting information, p. 675 - 688 (2020/03/11)
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