2406-17-9Relevant academic research and scientific papers
Bis(trifluoromethanesulfonimide) (BSI): Acidity and application to hydrofunctionalization as a Br?nsted acid catalyst
Takagi, Ryukichi,Sakai, Yuichiro,Duong, Duyen Thi
, (2021/03/23)
A binaphthyl derivative, bearing bis(trifluoromethanesulfonimide) (BSI) moiety, was developed as a novel Br?nsted acid. Computational prediction of the pKa value of BSI indicated its classification as a strong Br?nsted acid. BSI catalyzed the h
Highly Stereoselective Positional Isomerization of Styrenes via Acid-Catalyzed Carbocation Mechanism
Hu, Xiao-Si,He, Jun-Xiong,Zhang, Ying,Zhou, Jian,Yu, Jin-Sheng
supporting information, p. 2227 - 2233 (2021/06/28)
The first transition metal-free highly stereoselective positional isomerization of various α-alkyl styrenes through a carbocation mechanism triggered strategy is developed by using Al(OTf)3 as a hidden Br?nsted acid catalyst, which provides facile access to value-added acyclic tri- and tetra-substituted alkenes in good yields with high stereoselectivity under mild conditions. The practicality of this protocol is further highlighted by the gram-scale synthesis, high stereoselectivity, good functional group tolerance, and simple operation. Mechanistic studies support that Al(OTf)3 acts as a hidden Br?nsted acid catalyst and a carbocation intermediate is formed.
ZnI2/Zn(OTf)2-TsOH: A versatile combined-Acid system for catalytic intramolecular hydrofunctionalization and polyene cyclization
Chou, Ting-Hung,Yu, Bo-Hung,Chein, Rong-Jie
supporting information, p. 13522 - 13525 (2019/11/14)
A mild and efficient combined-Acid system using a zinc(ii) salt [ZnI2 or Zn(OTf)2] and p-Toluene sulfonic acid (TsOH) was investigated for catalytic cationic cyclizations, including intramolecular hydrocarboxylation, hydroalkoxylation, hydroamination, hydroamidation, hydroarylation and polyene cyclizations. This reaction provides easy access to five-and six-membered O-and N-containing saturated heterocyclic compounds, tetrahydronaphthalene derivatives and polycyclic skeletons in excellent yield with perfect Markovnikov selectivity and under mild conditions. The operational simplicity, broad applicability, and use of inexpensive commercially available catalysts make this protocol superior to existing methodologies.
Indium Catalyzed Hydrofunctionalization of Styrene Derivatives Bearing a Hydroxy Group with Organosilicon Nucleophiles
Kita, Yuji,Yata, Tetsuji,Nishimoto, Yoshihiro,Yasuda, Makoto
supporting information, p. 740 - 753 (2018/01/28)
Hydrofunctionalization is one of the most important transformation reactions of alkenes. Herein, we describe the development of an indium-triiodide-catalyzed hydrofunctionalization of alkenes bearing a hydroxy group using various types of organosilicon nucleophiles. Indium triiodide was the most effective catalyst, whereas typical Lewis acids such as TiCl4, AlCl3, and BF3·OEt2 were ineffective. Many functional groups were successfully introduced, and these resulted in yields of 31-86%. Various styrene derivatives were also applicable to this reaction. Mechanistic investigation revealed that the present hydrofunctionalization proceeded through Br?nsted acid-catalyzed intramolecular hydroalkoxylation of alkenes followed by InI3-catalyzed substitution reaction of cyclic ether intermediates.
Catalytic Synthesis of Saturated Oxygen Heterocycles by Hydrofunctionalization of Unactivated Olefins: Unprotected and Protected Strategies
Shigehisa, Hiroki,Hayashi, Miki,Ohkawa, Haruna,Suzuki, Tsuyoshi,Okayasu, Hiroki,Mukai, Mayumi,Yamazaki, Ayaka,Kawai, Ryohei,Kikuchi, Harue,Satoh, Yui,Fukuyama, Akane,Hiroya, Kou
supporting information, p. 10597 - 10604 (2016/09/04)
A mild, general, and functional group tolerant intramolecular hydroalkoxylation and hydroacyloxylation of unactivated olefins using a Co(salen) complex, an N-fluoropyridinium salt, and a disiloxane reagent is described. This reaction was carried out at ro
Cobalt-catalyzed oxidative cyclization of gem-disubstituted conjugated alkenols
Alves, Tania M.F.,Costa, Mateus O.,Bispo, Beatriz A.D.,Pedrosa, Fabiana L.,Ferreira, Marco A.B.
supporting information, p. 3334 - 3338 (2016/07/11)
Aryl gem-disubstituted conjugated alkenols underwent oxidative cyclization affording 2,5,5-trisubstituted tetrahydrofurans in reasonable yields and good diastereoselectivities using the reductive termination variation of the Mukaiyama aerobic oxidative reaction. Under oxidative termination, the same alkenols produced diols and ketonic by-products via the double hydration and beta-scission competing pathways. Furthermore, the differences in alkenol reactivity under the reductive and oxidative termination conditions were investigated.
Water opens the door to organolithiums and Grignard reagents: Exploring and comparing the reactivity of highly polar organometallic compounds in unconventional reaction media towards the synthesis of tetrahydrofurans
Cicco, Luciana,Sblendorio, Stefania,Mansueto, Rosmara,Perna, Filippo M.,Salomone, Antonio,Florio, Saverio,Capriati, Vito
, p. 1192 - 1199 (2016/02/09)
It has always been a firm conviction of the scientific community that the employment of both anhydrous conditions and water-free reaction media is required for the successful handling of organometallic compounds with highly polarised metal-carbon bonds. Herein, we describe how, under heterogeneous conditions, Grignard and organolithium reagents can smoothly undergo nucleophilic additions to γ-chloroketones, on the way to 2,2-disubstituted tetrahydrofurans, "on water", competitively with protonolysis, under batch conditions, at room temperature and under air. The reactivity of the above organometallic reagents has also been investigated in conventional anhydrous organic solvents and in bio-based eutectic and low melting mixtures for comparison. The scope and limitations of this kind of reaction are discussed.
Intramolecular Hydroalkoxylation of Unactivated Alkenes Using Silane-Iodine Catalytic System
Fujita, Shoji,Abe, Masanori,Shibuya, Masatoshi,Yamamoto, Yoshihiko
supporting information, p. 3822 - 3825 (2015/08/18)
A novel catalytic system using I2 and PhSiH3 for the intramolecular hydroalkoxylation of unactivated alkenes is described. NMR study indicated that in situ generated PhSiH2I is a possible active catalytic species. This catalytic system allows an efficient intramolecular hydroalkoxylation of phenyl-, trialkyl-, and 1,1-dialkyl-substituted alkenes as well as a variety of unactivated monoalkyl- and 1,2-dialkyl-substituted alkenes at room temperature. Mechanistic consideration based on significant experimental observations is also discussed.
Nickel complex catalyzed efficient activation of sp3and sp 2c-h bonds for alkylation and arylation of oxygen containing heterocyclic molecules
Gartia, Yashraj,Ramidi, Punnamchandar,Jones, Darin E.,Pulla, Sharon,Ghosh, Anindya
, p. 507 - 515 (2014/06/24)
A nickel(II) complex (1) of N,N'-bis(2,6-diisopropylphenyl)-2,6- pyridinedicarboxamido (L) ligand was examined for catalytic coupling of Grignard reagents with the C-H bond of oxygen containing heterocyclic compounds such as tetrahydrofuran and furan. The nickel( II) complex showed excellent activity in catalyzing C-H activation and further coupling with various Grignard reagents. The effective activation of the C-H bond proceeded under ambient reaction conditions with a short reaction time (1-2 h). The catalyst (1) displays high turnover frequency of 4,130 h-1with catalyst loading as low as 0.01 mol%. This catalytic route could prove to be an efficient mode of activation of sp3and sp2C-H bonds in various heterocycles for the preparation of synthetically and pharmaceutically relevant molecules. Springer Science+Business Media New York 2013.
Organotextile catalysis
Lee, Ji-Woong,Mayer-Gall, Thomas,Opwis, Klaus,Song, Choong Eui,Gutmann, Jochen Stefan,List, Benjamin
, p. 1225 - 1229 (2013/09/24)
Throughout human history, textiles have been integral to daily life, but their exploration in catalysis has been rare. Herein, we show a facile and permanent immobilization of organocatalysts on the textile nylon using ultraviolet light. The catalyst and
