28534-06-7Relevant academic research and scientific papers
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
CATALYSTS FOR (E)-SELECTIVE OLEFIN METATHESIS
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Page/Page column 0322, (2017/02/24)
This invention relates generally to olefin metathesis catalyst compounds, to the preparation of such compounds, and the use of such catalysts in the metathesis of olefins and olefin compounds, more particularly, in the use of such catalysts in (E)-selecti
Intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF: A synthetic approach to indene derivatives
Chen, Yan-Yan,Chen, Zhen-Yu,Zhang, Niu-Niu,Chen, Jia-Hua,Zhang, Xue-Jing,Yan, Ming
, p. 599 - 606 (2016/02/19)
A method for the intramolecular addition of triarylmethanes to alkynes has been developed. The reaction was efficiently promoted by KOtBu/DMF without any transition-metal catalyst. A variety of indene derivatives were prepared in moderate to good yields. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. The reaction is proposed to proceed through the generation of a triphenylmethyl radical. Indene derivatives were prepared by the intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. A free-radical reaction mechanism is proposed.
Branch-selective alkene hydroarylation by cooperative destabilization: Iridium-catalyzed ortho-alkylation of acetanilides
Crisenza, Giacomo E. M.,Sokolova, Olga O.,Bower, John F.
, p. 14866 - 14870 (2016/02/09)
An iridium(I) catalyst system, modified with the wide-bite-angle and electron-deficient bisphosphine dFppb (1,4-bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch-selective hydroarylation reactions between diverse acetanilides and aryl- or alkyl-substituted alkenes. This provides direct and ortho-selective access to synthetically challenging anilines, and addresses long-standing issues associated with related Friedel-Crafts alkylations. An iridium(I) catalyst system modified with the wide-bite-angle and electron-deficient bisphosphine dFppb (1,4-bis(di(pentafluorophenyl)phosphino)butane) promotes highly branch-selective hydroarylation reactions between diverse acetanilides and aryl- or alkyl-substituted alkenes. This provides direct and ortho-selective access to synthetically challenging anilines.
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.
Nucleophilic substitution reactions of alcohols with use of montmorillonite catalysts as solid Bronsted acids
Motokura, Ken,Nakagiri, Nobuaki,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 6006 - 6015 (2008/02/10)
(Chemical Equation Presented) We have developed an environmentally benign synthetic approach to nucleophilic substitution reactions of alcohols that minimizes or eliminates the formation of byproducts, resulting in a highly atom-efficient chemical process. Proton- and metal-exchanged montmorillonites (H- and Mn+-mont) were prepared easily by treating Na +-mont with an aqueous solution of hydrogen chloride or metal salt, respectively. The H-mont possessed outstanding catalytic activity for nucleophilic substitution reactions of a variety of alcohols with anilines, because the unique acidity of the H-mont catalyst effectively prevents the neutralization by the basic anilines. In addition, amides, indoles, 1,3-dicarbonyl compounds, and allylsilane act as nucleophiles for the H-mont-catalyzed substitutions of alcohols, which allowed efficient formation of various C-N and C-C bonds. The solid H-mont was reusable without any appreciable loss in its catalytic activity and selectivity. Especially, an Al3+-mont showed high catalytic activity for the α-benzylation of 1,3-dicarbonyl compounds with primary alcohols due to cooperative catalysis between a protonic acid site and a Lewis acidic Al3+ species in its interlayer spaces.
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
