20120-24-5Relevant articles and documents
Synthesis of a crosslinked polymer with a benzyl(triphenyl)phosphonium ionic liquid moiety and its catalytic activity
Liang, Xuezheng
, p. 99448 - 99453 (2015)
A novel crosslinked polymer with a benzyl(triphenyl)phosphonium ionic liquid moiety was synthesized from triphenylphosphine and p-xylylene dichloride. The bulky IL molecules were inlaid in the polymeric framework, which avoided pore blocking and IL moiety release. The polymer had a high BET surface area and accessible active sites. The polymer was applied to catalyze the aza-Michael additions and gave average yields over 95.0% in several minutes. The polymer had several advantages such as high BET surface area, high activity and high stability, which hold great potential for green chemical processes.
13C CP MAS NMR, FTIR, X-ray diffraction and PM3 studies of some N-(ω-carboxyalkyl)morpholine hydrohalides
Dega-Szafran,Ga?szczyk,Maciejewska,Szafran,Tykarska,Wawer
, p. 261 - 273 (2001)
N-(ω-carboxyalkyl)morpholine hydrochlorides, OC4H8N(CH2)nCOOH·HCI, n = 1-5, were obtained and analyzed by 13C cross polarization (CP) magic angle spinning (MAS) NMR, FTIR and PM3 calculations. The structure of N-(3-carboxy-propyl)morpholine hydrochloride (n = 3) has been solved by X-ray diffraction method at 100 K and refined to the R = 0.031. The crystals are monoclinic, space group P21/c, a = 14.307(3), b = 9.879(2), c = 7.166(1) A?, β = 93.20(3)°, V = 1011.3(3) A?3, Z = 4. In this compound the nitrogen atom is protonated and two molecules form a centrosymmetric dimer, connected by two N+-H···Cl- (3.095(1) A?) and two O-H···Cl- (3.003(1) A?) hydrogen bonds. 13C CP MAS NMR spectra, contrary to the solution, showed non-equivalence of the ring carbon atoms. The PM3 calculations predict a molecular dimer without proton transfer for an HCl complex, while for an HBr complex an ion pairs with proton transfer, and reproduces correctly the conformation of both dimers but overestimates H-bond distances. Shielding constants calculated from the PM3 geometry of ion pairs gave a linear correlation with the 13C chemical shifts in solids.
A comparison between nickel and palladium precatalysts of 1,2,4-triazole based N-heterocyclic carbenes in hydroamination of activated olefins
Dash, Chandrakanta,Shaikh, Mobin M.,Butcher, Ray J.,Ghosh, Prasenjit
, p. 2515 - 2524 (2010)
A comparison is drawn between the nickel and palladium precatalysts of 1,2,4-triazole based N-heterocyclic carbenes in the hydroamination of activated olefins. Though all of the newly designed nickel and palladium precatalysts, trans-[1-i-propyl-4-R-1,2,4-triazol-5-ylidene]2MBr2 [R = Et, M = Ni (1b); R = Et, M = Pd (1c); R = CH2CHCH2, M = Ni (2b) and R = CH2CHCH2, M = Pd (2c)], are moderately active for hydroamination reaction of a variety of secondary amines viz. morpholine, piperidine, pyrrolidine and diethylamine with activated olefins like, acrylonitrile, methyl acrylate, ethyl acrylate and t-butyl acrylate at room temperature in 1 hour, the nickel complexes (1b and 2b) exhibited superior activity compared to its palladium counterparts (1c and 2c). The better performance of the nickel complexes has been correlated to the more electron deficient metal center in the nickel 1b and 2b complexes than in the palladium 1c and 2c analogs based on the density functional theory studies. The 1b-c and 2b-c complexes were synthesized by the reaction of 1-i-propyl-4-R-1,2,4- triazolium bromide [R = Et (1a) and R = CH2CHCH2 (2a)] with MCl2 [M = Ni, Pd] in presence of NEt3 as a base. The Royal Society of Chemistry 2010.
An improved procedure for the synthesis of 2-morpholinoethanamine
Yao, Ri-Sheng,Wu, Sheng-Hua,Jiang, Lai-En,Deng, Sheng-Song,Yu, San-Xi
, p. 523 - 528 (2010)
2-Morpholinoethanamine is prepared rapidly mainly in aqueous conditions from inexpensive and commercially accessible starting materials. The process development of an effective synthetic route by utilizing morpholine as the starting material via Michael addition, hydrazinolysis, and Curtius rearrangements was undertaken. The optimal conditions were selected in the experiments. The total yield was 81.8% and it was a convenient process. Springer Science+Business Media B.V. 2010.
Human moricizine metabolism. I. Isolation and identification of metabolites in human urine
Richards,Pieniaszek Jr.,Shatzmiller,Page,Blom,Read,Davidson,Confalone
, p. 217 - 229 (1997)
1. Using synthetic standards and/or spectral data, seven moricizine metabolites were structurally identified in human urine. Two novel metabolites were identified as phenothiazine-2-carbamic acid and ethyl [10-(3-aminopropionyl) phenothiazin-2-yl] carbamate. Two novel human moricizine metabolites, 2-amino-10-(3-morpholinopropionyl) phenothiazine, a previously identified dog metabolite, and 2-aminophenothiazine, a previously identified rat metabolite, were also identified. Three additional human metabolites, phenothiazine-2-carbamic acid ethyl ester sulphoxide (P2CAEES), moricizine sulphoxide, and ethyl {10-[N-(2'-hydroxyethyl)3-aminopropionyl] phenothiazin-2-yl} carbamate, all previously described in the literature, were observed. 2. Both 2-amino-10-(3-morpholinopropionyl) phenothiazine and ethyl [10-(3-aminopropionyl) phenothiazin-2-yl] carbamate, and possibly ethyl {10-[N-(2'-hydroxyethyl)3-aminopropionyl]phenothiazin-2-yl} carbamate, possess the structural characteristics thought to be necessary for class 1 antiarrhythmic activity.
Promiscuous Candida antarctica lipase B-catalyzed synthesis of β-amino esters via aza-Michael addition of amines to acrylates
Dhake, Kishor P.,Tambade, Pawan J.,Singhal, Rekha S.,Bhanage, Bhalchandra M.
, p. 4455 - 4458 (2010)
An efficient protocol for the regioselective aza-Michael addition of amines with acrylates using CaL B as a biocatalyst at 60 °C has been developed. The reaction is applicable to a wide variety of primary and secondary amines with different acrylates to synthesize the corresponding β-amino esters with good yields. An alternative route for the synthesis of higher β-amino esters through the additional transesterification step is also studied and was found effective.
Efficient protocol for Aza-Michael addition of N-heterocycles to α,β-unsaturated compound using [Ch]OH and [n-butyl urotropinium]OH as basic ionic liquids in aqueous/solvent free conditions
Kumar, Sitanshu,Kaur, Amanpreet,Singh, Vasundhara
, p. 193 - 201 (2019/01/24)
The present work emphasizes on a green methodology using designed and synthesized basic ionic liquid, [n-butyl Urotropinium]OH, and commercially available aqueous solution of choline hydroxide [Ch]OH as catalysts for executing Aza-Michael addition of N-heterocycles to α,β-unsaturated compounds at room temperature. The highlighting features of these catalysts include using low concentration of both catalysts along with [Ch]OH being low cost and biodegradable, [n-butyl Urotropinium]OH significantly enhancing the high substrate/catalyst ratio to obtain the desired products in high yield and purity in most cases. Further, both catalysts were recyclable and recoverable up to five cycles.
Green synthesis of Ag@Au bimetallic regenerated cellulose nanofibers for catalytic applications
Gopiraman, Mayakrishnan,Saravanamoorthy, Somasundaram,Baskar, Ramaganthan,Ilangovan, Andivelu,Ill-Min, Chung
, p. 17090 - 17103 (2019/11/14)
The green synthesis of nanocomposites has attracted huge consideration in recent years due to its positive environmentally friendly impact. The present study reports the first bimetallic Ag-Au cellulose nanofiber composite (Ag@Au/CNCs) prepared via a very simple green preparation method. An aqueous leaves extract of Moringa oleifera was used to obtain the bimetallic Ag@Au/CNC nanocomposite. High-resolution transmission electron microscopy (HRTEM) observations revealed the successful formation of triangle, hexagonal, and spherical shapes of well-combined Ag-Au nanoparticles on the regenerated cellulose nanofiber surface. Further, the formation of Au-Ag bimetallic nanostructures was confirmed by X-ray photoelectron spectroscopy (XPS) and X-ray crystallography (XRD) results. The resultant bimetallic Ag@Au/CNC catalyst was found to perform remarkably well in the reduction of nitrophenols. The bimetallic Ag@Au/CNC catalyst gave excellent kapp values of 15.59 and 22.83 × 10-3 s-1 for the 2- A nd 4-nitrophenol reduction process, respectively. To our delight, the Ag@Au/CNC catalyst was found to perform well in the aza-Michael reaction. The catalytic activity of Ag@Au/CNCs was compared with mono-metallic Ag/CNCs, Au/CNCs, and other reported catalysts. Based on the results obtained, the high synergy of Ag@Au/CNCs was explained. A possible mechanism is proposed for the Ag@Au/CNC-catalyzed nitrophenol reduction and aza-Michael reactions.
A green and convenient approach for the one-pot solvent-free synthesis of coumarins and β-amino carbonyl compounds using Lewis acid grafted sulfonated carbon@titania composite
Kour, Manmeet,Paul, Satya
, p. 327 - 337 (2017/02/10)
Abstract: This paper reports an efficient protocol for the synthesis of coumarins via Pechmann reaction, and β-amino carbonyl compounds via aza-Michael reaction using catalytic amount of solid Lewis acid catalyst, C@TiO2–SO3–SbCl2. Six different catalysts were prepared by covalent immobilization of homogeneous Lewis acids onto sulfonated carbon@titania composite derived from amorphous carbon and nano-titania. Among various catalysts tested, C@TiO2–SO3–SbCl2 showed superior catalytic activity. The catalyst could be recycled without significant loss of its catalytic activity and demonstrated versatile catalysis for a wide range of substrates. Graphical abstract: [Figure not available: see fulltext.]
Nickel(II) N-Heterocyclic Carbene Complexes: Versatile Catalysts for C–C, C–S and C–N Coupling Reactions
Junquera, Lourdes Benítez,Fernández, Francys E.,Puerta, M. Carmen,Valerga, Pedro
supporting information, p. 2547 - 2556 (2017/05/29)
A variety of NiII complexes with a wide range of electronic and steric properties, bearing picolylimidazolidene ligands (a–g) and Cp (Cp = η5-C5H5; 2a–f) or Cp* (Cp* = η5-C5Me5; 3a, c, g) groups, have been synthesised and characterised by using NMR spectroscopy and single-crystal X-ray crystallography. The complexes have been used as precatalysts for a wide range of catalytic transformations, which most likely involve a Ni0/NiII catalytic cycle. In particular, the new well-defined 2a, 2c, 3a and 3c complexes have demonstrated great efficiency and versatility towards Suzuki–Miyaura coupling reactions, hydroamination of activated olefins and C–S cross-coupling reactions of aryl halides and thiols under mild conditions.
