- Synthesis of polystyrene-supported Pd(II)-NHC complex derived from theophylline as an efficient and reusable heterogeneous catalyst for the Heck-Matsuda cross-coupling reaction
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The polystyrene-supported palladium(II)-N-heterocyclic carbene complex PS-NHC-Pd(II) was successfully synthesized from theophylline as an environmentally benign NHC precursor, using chloromethylated polystyrene resin. The PS-NHC-Pd(II) complex was characterized by various techniques including Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), thermal analysis (TGA-DTG), inductively coupled plasma (ICP), and CHN elemental analysis. The morphology of the polymer beads was also studied using scanning electron microscope. The polymer supported Pd(II)-NHC complex exhibits excellent catalytic activity and stability for the Heck-Matsuda cross-coupling reaction under mild conditions. A variety of arenediazonium tetrafluoroborate salts was coupled with the olefinic substrates in ethanol, in the presence of the 0.9 mol% of the catalyst to afford the corresponding cross-coupling adducts in high yields under aerial conditions. Moreover, the heterogeneous catalyst can be easily recovered by simple filtration and reused for seven cycles without significant loss in its activity.
- Mohammadi, Elmira,Movassagh, Barahman
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p. 158 - 167
(2016/04/20)
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- Heck arylation of conjugated alkenes with aryl bromides or chlorides catalyzed by immobilization of palladium in MCM-41
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A new 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-2N-PdCl2] was conveniently synthesized from commercially available and cheap 3-(2-aminoethylamino) propyltrimethoxysilane via immobilization on MCM-41, followed by reacting with palladium chloride. It was found that this heterogeneous palladium complex is a highly efficient catalyst for Heck arylation of conjugated alkenes with aryl bromides or chlorides using tetrabutylammonium bromide as additive and can be reused for at least six consecutive trials without any decreases in activity.
- Yao, Fang,Liu, Jiaqin,Cai, Mingzhong
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p. 681 - 686
(2013/07/26)
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- Zinc-mediated facile synthesis of α,β-unsaturated primary amides
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A general method for the synthesis of α,β-unsaturated primary amides was achieved by an one-pot, triphenylphosphine-and zinc powder-promoted Wittig reaction of bromoacetamide and aldehydes under solvent-free conditions.
- Feng, Sunlin,Zhang, Zhiying,Jiang, Shilei,Yu, Xiaochun
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scheme or table
p. 382 - 384
(2010/11/03)
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- Medicaments 1,2,3,4-tetrahydrocarbazoles and 5-HT1 agonist use thereof
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Use of a compound of general formula (I): STR1 wherein R1 represents hydrogen, halogen, trifluoromethyl, nitro, hydroxy, C1-6 alkyl, C1-6 alkoxy, arylC1-6 alkoxy, --CO2 R4, --(CH2)n CN, --(CH2)n CONR5 R6, --(CH2)n SO2 NR5 R6, C1-6 alkanoylamino(CH2)n, or C1-6 alkylsulphonylamino(CH2)n ; R4 represents hydrogen, C1-6 alkyl or arylC1-6 alkyl; R5 and R6 each independently represent hydrogen or C1-6 alkyl, or R5 and R6 together with the nitrogen atom to which they are attached form a ring; n represents 0, 1 or 2; and R2 and R3 each independently represent hydrogen, C1-6 alkyl or benzyl or together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or hexahydroazepino ring; or a physiologically acceptable salt thereof, in the manufacture of a medicament for the treatment of a condition where a 5-HT1 -like agonist is indicated, for example migraine. Novel compounds of formula (I), processes for preparing them and pharmaceutical compositions containing them are also described.
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- Tetrahydrocarbazole derivatives for the manufacture of a medicament for the treatment of a disease where a 5-HT1-like agonist is indicated
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Use of a compound of general formula (I): wherein : R1represents hydrogen, halogen, trifluoromethyl, nitro, hydroxy, C1 6alkyl, C1 6alkoxy, arylC1 6alkoxy, -CO2R4, -(CH2)nCN, -(CH2)nCONR5R6,-(CH2)nSO2NR5R6,C1 6alkanoylamino(CH2)n, or C1 6alkylsulphonylamino (CH2)n; R4represents hydrogen, C1 6alkyl or arylC1 6alkyl; R5 and R6each independently represent hydrogen or C1 6alkyl, or R5 and R6 together with the nitrogen atom to which they are attached form a ring; nrepresents 0, 1 or 2; and R2 and R3each independently represent hydrogen, C1 6alkyl or benzyl or together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino or hexahydroazepino ring; or a physiologically acceptable salt thereof, in the manufacture of a medicament for the treatment of a condition where a 5-HT1-like agonist is indicated, for example migraine. Novel compounds of formula (I), processes for preparing them and pharmaceutical compositions containing them are also described.
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- REACTIONS OF ARYLDIAZONIUM TETRAFLUOROBORATES WITH ACRYLAMIDE IN THE PRESENCE OF THIOCYANATES, BROMIDES, AND CHLORIDES OF ALKALI METALS AND AMMONIUM
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The reaction of aryldiazonium tetrafluoroborates with acrylamide in a water-acetone mixture (1:2) in the presence of copper or iron salts and additives of thiocyanates (bromides, chlorides) of alkali metals and ammonium yields α-thiocyanato(bromo, chloro)-β-arylpropionamides. These compounds under the action of triethylamine easily eliminate hydrogen thiocyanate (bromide, chloride) with formation of β-arylacrylamides.
- Grishchuk, B. D.,Gorbovoi, P. M.,Kudrik, E. Ya.,Ganushchak, N. I.
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p. 1620 - 1623
(2007/10/02)
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