Domino reaction of anilines with 3,4-dihydro-2H-pyran catalyzed by cation-exchange resin in water: an efficient synthesis of 1,2,3,4-tetrahydroquinoline derivatives

2003 ◽  
Vol 5 (5) ◽  
pp. 627 ◽  
Author(s):  
Liang Chen ◽  
Chao-Jun Li
Keyword(s):  
Cation Exchange ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Domino Reaction ◽  
Efficient Synthesis

Cobalt(III) Complexes with 4-Methyldiethylene-triamine[2,2'-Methyliminodi(ethylamine)]: Their Separation, Characterization and Reactions

1979 ◽  
Vol 32 (3) ◽  
pp. 519 ◽  
Author(s):  
GH Searle ◽  
SF Lincoln ◽  
SG Teague ◽  
DG Rowe
Keyword(s):  
Catalytic Activity ◽  
Cation Exchange ◽  
Substitution Reaction ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Efficient Synthesis ◽  
Counter Ions ◽  
Visible Spectra ◽  
Oxygen Oxidation

An efficient synthesis of 2,2'-methyliminodi(ethylamine) trihydrochloride (medien,3HCl) from diethylenetriamine (dien) is described. The reactions [CO(NH3)5Cl] C12+2medien, and oxygen-oxidation of cobalt(II)+2medien, with charcoal give only the s-fac isomer of [Co(medien)]3+. A little s-fac-[Co(dien)(medien)]3+ is also always formed, and this arises by demethylation of s-fac-[Co(medien)2]3+ with oxygen on charcoal. The substitution reaction [Co(NH3)5Cl] Cl2 + 1.6 medien + 0.4 dien produces a complicated mixture of s-fac-[Co(medien)2]3+, all three isomers s-fac, u-fac and mer of [Co(dien)(medien)]3+, and all three isomers of [Co(dien)2]3+. A procedure using exchanges of the counter-ions, crystallization, and chromatography on SP-Sephadex cation-exchange resin is described for separating and isolating the products, and pure s-fac-[Co(dien)(medien)] (ClO4)3 is obtained preparatively by this means. From isomerization of this complex in water the pure u-fac and mer [Co(dien)(medien)]3+ isomers are isolated. 13C and 1H N.M.R. and visible spectra of the compounds are reported. The equilibrium isomer proportions of [Co(dien)2]3+, [Co(dien)(medien)]3+ and [Co(medien)2]3+ are discussed. Some particular charcoal samples, which lack catalytic activity towards cobalt(III) equilibrations, effect the unusual conversion of s-fac-[Co(medien)2]3+ into u-fac-[Co(arnam)]3+ (amam = 2,3-bis[(2-aminoethyl)(methyl)amino-ethylimino]-1-methylpiperazine).

Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst

2019 ◽  
Vol 16 (2) ◽  
pp. 288-293
Author(s):  
Yogesh W. More ◽  
Sunil U. Tekale ◽  
Nitishkumar S. Kaminwar ◽  
László Kótai ◽  
Tibor Pasinszki ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Cation Exchange ◽  
Copper Nanoparticles ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Environmentally Benign ◽  
High Yield ◽  
Carbon Microsphere ◽  
Catalytic Material ◽  
Operational Simplicity

Aim and Objective: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Materials and Methods: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. Results: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Conclusion: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

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