592-51-8Relevant academic research and scientific papers
A convergent approach to indolines and indanes
Ly, Thi-My,Quiclet-Sire, Beatrice,Sortais, Benoit,Zard, Samir Z.
, p. 2533 - 2536 (1999)
Radical addition of a xanthate to an N-allylanilide or to a substituted 4-aryl-1-butene followed by cyclisation onto the aromatic ring provide the corresponding indoline or indane respectively.
Palladium(II)-Catalyzed Aminotrifluoromethoxylation of Alkenes: Mechanistic Insight into the Effect of N-Protecting Groups
Chen, Chaohuang,Chen, Pinhong,Hou, Chuanqi,Liu, Guosheng
supporting information, p. 346 - 350 (2020/05/25)
An efficient palladium-catalyzed regioselective 5-exo aminotrifluoromethoxylation of alkenes has been established herein, which provides a practical route towards the synthesis of OCF3-containing pyrrolidines. tert-Butyloxycarbonyl (Boc) as an amino protecting group plays a significant role in both the chemo- and regioselectivities. In addition, preliminary mechanistic studies reveal that the amino protecting group of substrates and the counter anion of palladium catalyst play critical roles in reaction efficiency presumably due to an isomerization of alkyl- Pd(II) intermediates. Moreover, the asymmetric 5-exo aminotrifluoromethoxylation reaction has also been achieved by introducing a sterically bulky pyridinyl-oxazoline ligand.
Ni-Catalyzed hydrocyanation of alkenes with formamide as the cyano source
Shu, Xiao,Jiang, Yuan-Yuan,Kang, Lei,Yang, Luo
supporting information, p. 2734 - 2738 (2020/06/17)
CN generation from formamide dehydration! A novel Ni-catalyzed hydrocyanation of various alkenes to provide aliphatic nitriles is developed by generating hydrocyanic acid in situ from safe and readily available formamide. Excellent linear or branched regio-selectivity, wide substrate scope, cheap and stable nickel salt as a pre-catalyst, a safe cyano source, slow generation of CN to obviate catalyst deactivation and convenient experimental operation would render this hydrocyanation attactive for laboratory synthesis of aliphatic nitriles.
Rational design of efficient steric catalyst for isomerization of 2-methyl-3-butenenitrile
Han, Minghan,Liu, Kaikai,Wang, Tiefeng
, (2020/10/22)
The catalytic isomerization of 2-methyl-3-butenenitrile (2M3BN), a model reaction in the DuPont process, has been performed using NiL4 (L=tri-O-p-tolyl phosphite) as a catalyst. The lowered catalytic activity in the isomerization with coexistence of 2-pentenenitrile (2PN) and 2-methyl-2-butenenitrile (2M2BN) indicates that both 2PN and 2M2BN are the catalyst inhibitors, and the quantitative relationship between the conversion of 2M3BN and the content of 2M2BN and 2PN is provided. DFT calculation results suggest that the inhibition effect is attributed to the generation of dead-end intermediates (2PN)NiL2 and (2M2BN)NiL2, both of which take nickel atom out of the catalytic cycle in the isomerization process. To suppress the inhibition effect, new catalytic intermediates are rationally designed based on their computational %Vbur. An efficient method that adding extra ligand 1, 5-bis(diphenylphosphino)pentane (dppp5) to the NiL4 catalyst is selected experimentally. Compared to the results obtained with NiL4 as catalyst, the (dppp5)NiL2 increases the conversion of 2M3BN from 74.5 % to 93.4 % at 3 h of reaction and provides a high selectivity to 3PN (> 98 %) at optimal conditions.
I2-Mediated oxidative bicyclization of 4-pentenamines to prolinol carbamates with CO2 incorporating oxyamination of the C=C bond
Wang, Sheng,Zhang, Xiaowei,Cao, Chengyao,Chen, Chao,Xi, Chanjuan
supporting information, p. 4515 - 4519 (2017/10/13)
A metal-free oxyamination reaction of alkenes with ambient CO2 is reported. In the presence of I2 and DBU, CO2 is applied in situ as a protecting group to regulate the nucleophilicity of the amino group and facilitate the bicyclization of 4-pentenamines with high chemoselectivity. Moreover, this reaction provided a feasible approach to prepare prolinol carbamates with good tolerance of functional groups and high efficiency under mild conditions.
Design of Core-Pd/Shell-Ag Nanocomposite Catalyst for Selective Semihydrogenation of Alkynes
Mitsudome, Takato,Urayama, Teppei,Yamazaki, Kenji,Maehara, Yosuke,Yamasaki, Jun,Gohara, Kazutoshi,Maeno, Zen,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
supporting information, p. 666 - 670 (2016/02/18)
We designed core-Pd/shell-Ag nanocomposite catalyst (Pd@Ag) for highly selective semihydrogenation of alkynes. The construction of the core-shell nanocomposite enables a significant improvement in the low activity of Ag NPs for the selective semihydrogenation of alkynes because hydrogen is supplied from the core-Pd NPs to the shell-Ag NPs in a synergistic manner. Simultaneously, coating the core-Pd NPs with shell-Ag NPs results in efficient suppression of overhydrogenation of alkenes by the Pd NPs. This complementary action of core-Pd and shell-Ag provides high chemoselectivity toward a wide range of alkenes with high Z-selectivity under mild reaction conditions (room temperature and 1 atm H2). Moreover, Pd@Ag can be easily separated from the reaction mixture and is reusable without loss of catalytic activity or selectivity.
Green, Multi-Gram One-Step Synthesis of Core–Shell Nanocomposites in Water and Their Catalytic Application to Chemoselective Hydrogenations
Urayama, Teppei,Mitsudome, Takato,Maeno, Zen,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
supporting information, p. 17962 - 17966 (2016/12/16)
We devise a new and green route for the multi-gram synthesis of core–shell nanoparticles (NPs) in one step under organic-free and pH-neutral conditions. Simply mixing core and shell metal precursors in the presence of solid metal oxides in water allowed for the facile fabrication of small CeO2-covered Au and Ag nanoparticles dispersed on metal oxides in one step. The CeO2-covered Au nanoparticles acted as a highly efficient and reusable catalyst for a series of chemoselective hydrogenations, while retaining C=C bonds in diverse substrates. Consequently, higher environmental compatibility and more efficient energy savings were achieved across the entire process, including catalyst preparation, reaction, separation, and reuse.
Photoredox-Catalyzed Intramolecular Aminodifluoromethylation of Unactivated Alkenes
Zhang, Zuxiao,Tang, Xiaojun,Thomoson, Charles S.,Dolbier, William R.
supporting information, p. 3528 - 3531 (2015/07/28)
A photoredox catalyzed aminodifluoromethylation of unactivated alkenes has been developed in which HCF2SO2Cl is used as the HCF2 radical source. Sulfonamides were active nucleophiles in the final step of a tandem addition/oxidation/cyclization process to form pyrrolidines, and esters were found to cyclize to form lactones. Thus, a variety of pyrrolidines and lactones were obtained in moderate to excellent yield. In order for the cyclization reactions to be efficient, a combination of a copper catalyst (Cu(dap)2Cl) and silver carbonate was crucial to suppressing a competing chloro, difluoroalkylation process.
PROCESS FOR ISOMERIZATION OF CIS-2-PENTENENITRILE TO 3-PENTENENITRILES
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Paragraph 0066-0068, (2017/01/02)
Discontinuous or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles, comprises isomerizing cis-2-pentenenitrile with tertiary amine compounds (I) and their mixtures. Discontinuous or continuous isomerization of cis-2-pentenenitrile to 3-pentenenitriles, comprises isomerizing cis-2-pentenenitrile with tertiary amine compounds of formula (I) and their mixtures. R1, R2 : H, linear or branched 1-5C-alkyl, 5-7C-cycloalkyl, hydroxyethyl or ethylene group bridging two N. [Image].
Enantioselective diamination with novel chiral hypervalent iodine catalysts
Mizar, Pushpak,Laverny, Aragorn,El-Sherbini, Mohammad,Farid, Umar,Brown, Michael,Malmedy, Florence,Wirth, Thomas
supporting information, p. 9910 - 9913 (2014/08/18)
Vicinal diamines constitute one the most important functional motif in organic chemistry because of its wide occurrence in a variety of biological and pharmaceutical molecules. We report an efficient metal-free, highly stereoselective intramolecular diamination using a novel chiral hypervalent iodine reagent together with its application as an efficient catalyst for the synthesis of diamines.
