19 research outputs found
2′-Methyl-2′-nitro-1′-phenyl-2′,3′,5′,6′,7′,7a’-hexaÂhydroÂspiroÂ[indoline-3,3′-1′H-pyrrolizin]-2-one
The title compound, C21H21N3O3, was synthesized by a multi-component 1,3-dipolar cycloÂaddition of azomethine ylide, derived from isatin and proline by a decaÂrboxylative route, and (E)-1-phenyl-2-nitroÂpropene. In the molÂecule, the spiro junction links a planar oxindole ring and a pyrrolidine ring in an envelope conformation. The molÂecular packing is stabilized by an interÂmolecular N—H⋯N interÂaction of the oxindole and pyrrolizidine rings
An expedient approach for the regio- and stereoselective synthesis of novel spiroindolizidines via [3+2] cycloaddition
Furolabdane diterpenoids from <i>Pseudodictamnus aucheri</i> (Boiss.) Salmaki & Siadati (Lamiaceae) as chemophenetic markers
An efficient synthesis of novel triazoles incorporating barbituric motifs via [3+2] cycloaddition reaction: An experimental and theoretical study
In this work, the synthesis of novel triazole derivatives with barbituric motifs in good yields is described. The alkyne was prepared through the Knoevenagel reaction of barbituric derivatives with ortho and para O-propargylated hydroxybenzaldehyde. The mechanism and regioselectivity of this [3+2] cycloaddition reaction were investigated using the density functional theory at the B3LYP/6-31+G(d) level of theory. The computational studies revealed that a di-copper catalyzed stepwise mechanism, involving six-membered ring intermediate, is the preferred pathway. The regioselectivity was explained in terms of frontier molecular orbital (FMO) interactions, local and global electrophilicity and nucleophilicity indices. Accordingly, the favored interactions for di-copper acetylide are in good agreement with the observed regioselectivity, while completely opposite results were obtained for a possible uncatalysed reaction
Antioxidant and antidiabetic activities of 11 herbal plants from Hyrcania region, Iran
In the present study, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, α-amylase and α-glucosidase inhibition activities, and total phenolic contents of n-hexane, ethyl acetate, and methanol extracts of various parts of Allium paradoxum, Buxus hyrcana, Convolvulus persicus, Eryngium caucasicum, Heracleum persicum, Pimpinella affinis, Parrotia persica, Primula heterochroma, Pyrus boissieriana, Ruscus hyrcanus, and Smilax excelsa were investigated. These plants, which mostly serve as food flavoring, were collected from Hyrcania region, Sari, Iran. Some extracts of H. persicum, S. excels, P. boissieriana, P. persica, and P. heterochroma exhibited significant antidiabetic activities in α-amylase and α-glucosidase assays, more effective than acarbose (concentrations that cause 50% inhibition = 75.7 μg/mL and 6.1 μg/mL against α-amylase and α-glucosidase, respectively). Also, C. persicus, P. boissieriana, and P. heterochroma showed strong antioxidant activities, compared with butylated hydroxytoluene (concentration that causes 50% inhibition = 16.7 μg/mL). In conclusion, this study can recommend these plants as good candidates for further investigations to find potent antidiabetic natural products or probable lead compounds. Statistical analysis showed significant correlation between the 2,2-diphenyl-1-picrylhydrazyl scavenging activity and total phenolic contents (r = 0.711, p < 0.001)
An expedient approach for the regio- and stereoselective synthesis of novel spiroindolizidines via [3+2] cycloaddition
A theoretical investigation on the regioselectivity of the intramolecular hetero Diels-Alder and 1,3-dipolar cycloaddition of 2-vinyloxybenzaldehyde derivatives
The present study reports a systematic computational analysis of the two
possible pathways, fused and bridged, for an intramolecular hetero
Diels-Alder (IMHDA) and an intramolecular 1,3-dipolar cycloaddition (IMDCA)
of 2-vinyloxybenzaldehyde derivatives. The potential energy surface analysis
for both reactions is in agreement with experimental observations. The
activation energies associated with the two regioisomeric channels in IMHDA
reaction show that the bridged product is favored, although in IMDCA, the
most stable TS results the fused product. The global electronic properties
of fragments within each molecule were studied to discuss the reactivity
patterns and charge transfer direction in the intramolecular processes. The
asynchronicity of the bond formation and aromaticity of the optimized TSs in
the Diels-Alder reaction as well as cycloaddition reaction were evaluated.
Finally, 1H NMR chemical shifts of the possible regioisomers have been
calculated using the GIAO method which of the most stable products are in
agreement with the experimental data in the both reaction