1075-76-9Relevant articles and documents
β-Cyclodextrin promoted aza-Michael addition of amines to conjugated alkenes in water
Surendra,Krishnaveni, N. Srilakshmi,Sridhar,Rao, K. Rama
, p. 2125 - 2127 (2006)
Highly efficient and environmentally benign aza-Michael additions of amines to α,β-unsaturated compounds catalyzed by β-cyclodextrin in water to produce the corresponding β-amino compounds in excellent yields under mild conditions are described. β-Cyclodextrin can be recovered and reused in subsequent reactions without loss of activity.
A catalytic method for room-temperature Michael additions using 12-tungstophosphoric acid as a reusable catalyst in water
Chen, Xiang,She, Jin,Shang, Zhicai,Wu, Jun,Zhang, Peizhi
, p. 3931 - 3936 (2008)
12-Tungstophosphoric acid (H3PW12O40) has been found to be an efficient and recyclable catalyst in promoting room temperature Michael additions of amines and aryl thiols to α,β- unsaturated esters and acrylonitrile in water to afford the corresponding saturated amines in good to excellent yields. Georg Thieme Verlag Stuttgart.
Air- and moisture-stable cationic (diphosphine)palladium(II) complexes as hydroamination catalysts X-ray crystal structures of two complexes
Li, Kelin,Horton, Peter N.,Hursthouse, Michael B.,Hii, King Kuok Mimi
, p. 250 - 257 (2003)
A series of cationic (diphosphine)palladium(II) complexes have been prepared and fully characterized, including two crystal structures. These complexes were evaluated as catalysts for the hydroamination of acyclic alkenes. The reactivity of the catalysts is dependent on the nature of the diphosphine ligand and the substituents on the amine and alkene substrates.
Solid sodium stannate as a high-efficiency superbase catalyst for anti-Markovnikov hydroamination and hydroalkoxylation of electron-deficient olefins under mild conditions
Zhang, Shuguo,Wei, Yudan,Yin, Shuangfeng,Au, Chak-Tong
, p. 712 - 716 (2011)
A solid superbase with H- above 26.5 has been obtained through thermal treatment of sodium stannate hydrate. It was found to be an efficient catalyst for anti-Markovnikov hydroamination and hydroalkoxylation of electron-deficient olefins under mild conditions.
TiCl2(OTf)-SiO2: A solid stable lewis acid catalyst for Michael addition of α-Aminophosphonates, Amines, Indoles and Pyrrole
Firouzabadi, Habib,Iranpoor, Naser,Farahi, Soghra
, p. 317 - 323 (2018)
TiCl2(OTf)-SiO2 is simply prepared by immobilization of TiCl3(OTf) on silica gel surface and introduced as a non-hygroscopic Lewis acid catalyst for C-N and C-C bond formation via Michael addition reaction. A variety of structurally diverse nitrogen nucleophiles including α-aminophosphonates, aliphatic and aromatic amines and imidazole were evaluated as Michael donors. Friedel–Crafts alkylation of indoles and pyrrole was also investigated through Michael addition reaction in the presence of TiCl2(OTf)-SiO2 as a catalyst. The reactions were conducted at room temperature or 60 °C under solvent-free conditions and the desired Michael adducts were obtained in high to excellent yields.
Cyanoethylation of alcohols and amines by cesium-modified zeolite y
Zamanian, Sara,Kharat, Ali Nemati
, p. 264 - 269 (2014)
Zeolite Y modified by cesium and magnesium ions was prepared by ion-exchange and impregnation methods, and its activity in the cyanoethylation of aliphatic and aromatic alcohols and amines was investigated. During the preparation of some samples, the transformation of zeolite Y into a pollucite-type phase occurred. This phase exhibited good activity in the cyanoethylation of aliphatic alcohols. The prepared solids modified by the impregnation method were more active than the ion-exchanged solids. The activities of the catalysts, in contrast to other basic solids, were scarcely affected by the presence of air or moisture. A correlation between catalyst basicity and catalytic activity is discussed. The catalysts were characterized by X-ray diffraction, volumetric nitrogen adsorption surface area measurement, and CO2 temperature-programmed desorption. Scanning electron microscopy revealed that the particles of the modified nanocatalysts were 40 nm. The reaction of acrylonitrile with linear alcohols in the presence of the catalysts was accelerated by microwave irradiation.
Synthesis of β-amino esters via aza-Michael addition of amines to alkenes promoted on silica: A useful and recyclable surface
Basu, Basudeb,Das, Pralay,Hossain, Ismail
, p. 2630 - 2632 (2004)
A solvent-free protocol for the synthesis of β-amino esters and nitriles has been developed via conjugate addition of amines to electron-deficient alkenes promoted on silica. The silica surface may be recycled. Both aliphatic and aromatic primary or secondary amines worked efficiently to yield the desired adducts in good to excellent yields.
Polymer coated magnetically separable organocatalyst for C[sbnd]N bond formation via aza-Michael addition
Panwar, Vineeta,Ray, Siddharth S.,Jain, Suman L.
, p. 5026 - 5032 (2016)
A polyacrylamide coated magnetite (PAM@MNP) catalyst was synthesized by following a two step approach involving the reaction of magnetite (Fe3O4) particles with coupling agent 3-(trimethoxysilyl)propyl methacrylate followed by grafting of acrylamide and subsequent polymerization via surface initiated radical polymerization technique. The synthesized organocatalyst was used for a one-pot aza-Michael addition reaction of amines with electron deficient alkenes to give β-amino carbonyls. The magnetic properties of the synthesized organocatalyst provide it a facile recovery by external magnet which eliminates the problems arising during catalyst separation by conventional filtration.
Tandem bis-aza-Michael addition reaction of amines in aqueous medium promoted by polystyrenesulfonic acid
Polshettiwar, Vivek,Varma, Rajender S.
, p. 8735 - 8738 (2007)
An efficient and environmentally benign tandem bis-aza-Michael addition of amines catalyzed by polystyrenesulfonic acid (PSSA) is described. This operationally simple high yielding microwave assisted synthetic protocol proceeded in water in the absence of any organic solvent.
Bio-heterogeneous Cu(0)NC@PHA for n-aryl/alkylation at room temperature
Jian Fui, Choong,Lutfor Rahman, Md,Musta, Baba,Sani Sarjadi, Mohd,Sarkar, Shaheen M.,Xin Ting, Tang
, (2021/06/28)
A pure cellulose was derived from waste fibre and it was chemically modified to a hydroxamic acid ligand. The poly(hydroxamic acid) was treated with an aqueous copper solution to afford the greenish stable five-membered copper complex; namely Cu(II)@PHA. Further, the Cu(II)@PHA was treated with a reducing agent hydrazine hydride to give brown colour cellulose supported copper nanocomplex (Cu(0)NC@PHA). The Cu(0)NC@PHA was characterised by ATR-FTIR, FE-SEM & EDS, TEM, ICP-OES, TGA, XRD and XPS analyses. The cellulose-based Cu(0)NC@PHA was used for the n-aryl/alkylation (Michael addition) reaction with a variety of α,β-unsaturated Michael acceptors to produce the corresponding n-aryl/alkyl products with an excellent yield at room temperature. The Cu(0)NC@PHA showed extraordinary stability and it was easily filtered out from the reaction mixture and may potentially recycled up to five times without loss of its original catalytic ability.
Continuous Synthesis of Aryl Amines from Phenols Utilizing Integrated Packed-Bed Flow Systems
Ichitsuka, Tomohiro,Kobayashi, Shū,Koumura, Nagatoshi,Sato, Kazuhiko,Takahashi, Ikko
, p. 15891 - 15896 (2020/07/13)
Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week.
