3159-01-1Relevant academic research and scientific papers
New chiral α-diimine nickel(II) complexes bearing ortho-sec-phenethyl groups for ethylene polymerization
Wang, Fuzhou,Yuan, Jianchao,Song, Fengying,Li, Jing,Jia, Zong,Yuan, Bingnian
, p. 319 - 327 (2013)
A series of new α-diimine nickel(II) catalysts bearing bulky chiral sec-phenethyl groups have been synthesized and characterized. The molecular structure of representative chiral ligand, bis[N,N′-(4-methyl-2,6-di-sec- phenethylphenyl)imino]-1,2-dimethylethane rac-1c and chiral complexes, {bis[N,N′-(4-methyl-2-sec-phenethylphenyl)imino]-2,3-butadiene} dibromidonickel rac-2a and bis{bis[N,N′-(4-methyl-2-sec-phenethylphenyl) imino]-2,3-butadiene}dibromidonickel rac-2b, were confirmed by X-ray crystallographic analysis. Complex rac-2c bearing two chiral sec-phenethyl groups in the ortho-aryl position and a methyl group in the para-aryl position, activated by diethylaluminum chloride (DEAC), showed highly catalytic activity for the polymerization of ethylene [4.12 × 106 g PE (mol Ni.h.bar)-1], and produced highly branched polyethylenes under low ethylene pressure (branching degree: 104, 118 and 126 branches/1000 C at 20, 40 and 60°C, respectively). Chiral 20-electron bis-α-diimine Ni(II) complex rac-2b also exhibited high activity toward ethylene polymerization [1.71 × 106 g PE (mol Ni · h · bar)-1]. The type and amount of branches of the polyethylenes obtained were determined by 1H and 13C NMR. Copyright
Zeolite catalyzed hydroarylation of alkenes with aromatic amines under organic ligand-free conditions
Li, Teng,Liu, Shujuan,Shi, Feng,Wang, Hongli,Wang, Xinzhi,Yuan, Hangkong,Zhao, Kang
, p. 18 - 29 (2021/01/12)
The hydroarylation of alkenes with aromatic amines is recognized as the most atom-economical and straightforward approach to obtain functional aromatic amines, which are versatile building blocks in organic synthesis and material chemistry. However, controllable synthesis of single hydroarylation product is still a significant challenge because hydroarylation reaction often delivers four hydroarylation products and hydroamination products are also produced during the reaction. Herein, we report the first example of heterogeneous zeolite catalyzed hydroarylation of styrene and norbornene with aniline derivatives under organic ligand-free conditions. With the USY zeolite as catalyst, a wide scope of alkenes and aromatic amines with various functional groups are smoothly converted into the corresponding products in 48–95% yields with high regioselectivity. Detailed characterizations revealed that Lewis acid can promote Hofmann-Martius rearrangement of hydroamination products toward hydroarylation products, resulting in high selectivity for hydroarylation products. In addition, it could be found that the weak acid sites of zeolite play a key role in forming hydroarylation products. Furthermore, the catalyst can be reused at least 10 times without obvious deactivation. This work may promote the development of heterogeneous catalyst system for alkene hydroarylation.
On the Superior Activity of In(I) versus In(III) Cations Toward ortho-C-Alkylation of Anilines and Intramolecular Hydroamination of Alkenes
Li, Zhilong,Yang, Shengwen,Thiery, Guillaume,Gandon, Vincent,Bour, Christophe
, p. 12947 - 12959 (2020/11/23)
An efficient ortho-C-alkylation of unprotected anilines with a variety of styrenes and alkenes using a univalent cationic indium(I) catalyst is reported. Mechanistic studies revealed that the reaction likely proceeds via a tandem hydroamination/Hofmann-Martius rearrangement. The high compatibility between the cationic indium(I) complex and primary anilines led us to develop an In(I)+-catalyzed hydroamination of alkenes using unprotected primary and secondary alkenylamines. Computations support the catalytic activity of naked In(I)+ ions, with an outer sphere mechanism for the C-N bond formation and a potentially inner sphere protodemetallation.
Cobalt-Catalyzed Hydroarylations and Hydroaminations of Alkenes in Tunable Aryl Alkyl Ionic Liquids
Schroeter, Felix,Lerch, Swantje,Kaliner, Maria,Strassner, Thomas
supporting information, p. 6215 - 6219 (2018/10/05)
Tunable aryl alkyl ionic liquids (TAAILs) are a promising class of imidazolium- or triazolium-based ionic liquids. Contrary to "standard" all-alkyl ionic liquids, these carry an aryl ring together with a linear or branched alkyl chain. Their application i
New nickel(II) diimine complexes bearing phenyl and sec-phenethyl groups: Synthesis, characterization and ethylene polymerization behaviour
Wang, Fuzhou,Yuan, Jianchao,Li, Qingshan,Tanaka, Ryo,Nakayama, Yuushou,Shiono, Takeshi
, p. 477 - 483 (2014/07/07)
A series of nickel(II) catalysts containing phenyl and chiral sec-phenethyl groups, {[(4-R1-2-R2C6H2-Rfnet C)2Nap]NiBr2} (Nap: 1,8-naphthdiyl, R1=Me, R2=Ph (3a); R1=Me, R2=sec-phenethyl (3b); R1=Cl, R2=sec-phenethyl (3c); R1=Me, R 2=Me (3d) were synthesized and characterized. All organic compounds were fully characterized by FT-IR and NMR spectroscopy and elemental analysis. The single crystal for X-ray crystallography was isolated from 3a in CH 2Cl2/n-hexane under air; the crystal structure showed a binuclear complex 3a, in which each nickel atom was six-coordinate. The two nickel atoms together with two bromine atoms form a planar four-membered ring, with a bromine and H2O axial ligands. These complexes, activated by diethylaluminum chloride and chiral nickel pre-catalysts rac-3c, exhibited good activities (up to 2.85×106g PE (mol Ni h bar)-1) for ethylene polymerization, and produced polyethylene products with a high degree of branching (up to 117 branched per 1000 carbons) at high temperature. The type and amount of branches of the polyethylenes obtained were determined by 1H and 13C NMR spectroscopy. Copyright
Zinc triflate-catalyzed intermolecular hydroamination of vinylarenes and anilines: Scopes and limitations
Liu, Gong-Qing,Li, Yue-Ming
experimental part, p. 7168 - 7170 (2012/01/04)
Intermolecular hydroamination of vinylarenes and anilines was studied using zinc triflate as catalyst. NMR experiments supported a Lewis acid activation of the CC double bond. Electronic/steric effect study indicated that Lewis acidity of the catalyst as well as the coordination property of the amine were the governing factors for successful hydroamination of the substrates. More nucleophilic amine would bind more tightly to the central metal, leading to an unproductive coordination. Approach of bulky amine to CC bond would be hindered, and an alternative electrophilic substitution on benzene ring of the amine would become the major reaction. Electrophilic substitution would become predominant when strong electron-donating group is presented on aniline benzene ring.
A simple catalyst for the efficient benzylation of arenes by using alcohols, ethers, styrenes, aldehydes, or ketones
Prades, Amparo,Corberan, Rosa,Poyatos, Macarena,Peris, Eduardo
experimental part, p. 4610 - 4613 (2009/12/26)
The compound [IrCp* (OTf)2(InBu)] (I nBu = 1,3-di-n-butyl-imidazolylidene) is an effective catalyst in the benzylation of arenes with different benzylating agents, such as alcohols, ethers and styrenes, representing an unprecedented highly versatile catalyst for this type of process. The same compound also catalyses a remarkable tandem process that allows the use of aldehydes and ketones as benzylating agents, through the base-free hydrogenation of C=O bonds with iPrOH and further use of the resulting primary or secondary alcohols as benzylating agents.
Intermolecular hydroamination of vinyl arenes using tungstophosphoric acid as a simple and efficient catalyst
Seshu Babu,Mohan Reddy,Sai Prasad,Suryanarayana,Lingaiah
, p. 7642 - 7645 (2008/03/14)
The intermolecular hydroamination of vinyl arene derivatives has been efficiently carried out using a tungstophosphoric acid (TPA) catalyst under solvent free and mild reaction conditions. The present protocol provides an environmentally benign, easy to handle and highly active solid acid catalyst for hydroamination of vinyl arenes. The catalyst yields both hydroamination and hydroarylation products and the selectivity mostly depends on the reaction conditions.
HI-catalyzed hydroamination and hydroarylation of alkenes
Marcsekova, Klaudia,Doye, Sven
, p. 145 - 154 (2007/12/27)
Aromatic amines react with alkenes in the presence of catalytic amounts of aqueous HI to give mixtures ef the corresponding hydroamination and hydroarylation products. While the hydroamination reaction is the preferred pathway for aliphatic alkenes, the h
Titanium-catalyzed intermolecular hydroamination of vinylarenes
Kaspar, Ludwig T.,Fingerhut, Benjamin,Ackermann, Lutz
, p. 5972 - 5974 (2007/10/03)
(Chemical Equation Presented) The Lewis acid TiCl4 allows the intermolecular hydroamination of vinylarenes (see scheme). Some of the hydroamination products undergo rearrangements to give ortho-alkylated compounds. The catalyst tolerates a rang
