This study aimed to compare the untreated, cold plasma (CP)-optimized (30 kV/5 mm/6.7 min), CP-extreme (30 kV/2 mm/10 min), and thermally treated (TT) (90 ℃/5 min) kiwifruit juices based on the physicochemical (pH, total soluble solids (TSS), titratable acidity (TA), total color change (ΔE)), physical (particle size and rheology), microstructure (optical microscope), bioactive compounds (polyphenol, ascorbic acid, and sugar compounds), and sensory characteristics of kiwifruit juice. The pH, TSS, and TA were not significantly affected in CP and TT juice, whereas the ΔE (6.
View Article and Find Full Text PDFNovel finding of aldehyde in 2-oxoaldehyde (2OA) is presented as it unprecedentedly disinclines to react with Grignard reagents but reacts with moderate organocuprate reagents in anaerobic condition to give [1,2] addition (α-hydroxyketones) reaction. In the presence of air, the reaction produces an efficient protocol for the synthesis of 1,2-diones through a copper-catalyzed oxidative cross-coupling reaction at room temperature. Mechanistic studies indicate that α-hydroxy ketone perhaps is generated before the hydrolysis step/acid work-up process.
View Article and Find Full Text PDFBioorg Chem
October 2021
With the aim to discover potent and novel antitumor agents, a series of thiourea compounds bearing 3-(4-methoxyphenyl)azetidine moiety were designed according to the essential pharmacophoric features of the reported VEGFR-2 inhibitors and synthesized. All the synthesized compounds were evaluated for their in vitro anticancer activity against various human cancer cell lines (lung (A549), prostate (PC3), breast (MCF-7), liver (HepG2), colon (HCT-116), ovarian (SKOV-3), skin (A431), brain (U251) and kidney (786-O)). 3-(4-Methoxy-3-(2-methoxypyridin-4-yl)phenyl)-N-(4-methoxyphenyl)azetidine-1-carbothioamide (3B) was found to be most potent member against PC3, U251, A431, and 786-O cancer cell lines with EC values 0.
View Article and Find Full Text PDFAn efficient functional group induced strategy for the synthesis of 6-aminophenanthridines (6AP) has been developed as a result of an in situ generated novel system "CO-CH(N1N2)". This reaction presents a new mode of N2 extrusion in benzotriazoles that later result in decarbonylative cyclization to 6AP. This method offers an easier protocol for the synthesis of 6AP from readily available inexpensive substrates.
View Article and Find Full Text PDFThe potential of TBHP to promote oxidative hydroxylation of α-hydroxy-β-oxophosphonates (HOPs) through C(CO)-C bond cleavage is described. This cleavage, as depicted in the mechanism is expected through an isomer of HOP that reacts with TBHP to generate acids.
View Article and Find Full Text PDFHighly efficient catalyst free methods for the synthesis of α-hydroxy-β-oxophosphonates and α-oxoesters have been described. The existence of a 2-oxo group in α-oxoaldehydes is a key factor in promoting the reaction of the tervalent phosphite form towards 2-oxoaldehydes in the synthesis of α-hydroxy-β-oxophosphonates. The in situ activated α-C-H atom of α-hydroxy-β-oxophosphonates sustains aerobic intramolecular nucleophilic displacement in a curious way to produce α-oxoester.
View Article and Find Full Text PDFA highly efficient, novel, microwave-assisted, metal-free, diastereoselective synthesis of tetrahydrofuro[3,2-d]oxazole is disclosed. The synthesis of napthoxazoles is achieved for the first time without the aid of an external catalyst. On the contrary, our reactions generated naphthofuranones when treated in the presence of metals in microwave/thermal conditions.
View Article and Find Full Text PDFGiven the attractive ability of iminium ions to functionalize molecules directly at ostensibly unreactive positions, the reactivity of iminium ions, in which an α CH2 group is replaced by CO was explored. Background studies on the ability of such iminium cations to promote reactions via an iminium-catalyzed or iminium-equivalent pathway are apparently unavailable. Previously, tandem cross-coupling reactions were reported, in which an iminium ion undergoes nucleophilic 1,2-addition to give a putative three-component intermediate that abstracts a proton in situ and undergoes self-deamination followed by unprecedented DMSO/aerobic oxidation to generate α-ketoamides.
View Article and Find Full Text PDFA novel and efficient method for the synthesis of α-ketoamides, employing a dimethyl sulfoxide (DMSO)-promoted oxidative amidation reaction between 2-oxoaldehydes and amines under metal-free conditions is presented. Furthermore, mechanistic studies supported an iminium ion-based intermediate as a central feature of reaction wherein C1-oxygen atom of α-ketoamides is finally derived from DMSO.
View Article and Find Full Text PDFAn efficient one-pot multi-component synthesis of flavans using perchloric acid supported on silica as a recyclable heterogeneous catalyst has been described. This is the first report of direct one-step construction of a flavan skeleton from a phenolic precursor. The method involves a Knoevenagel-type condensation leading to in situ formation of transient O-quinone methide which further undergoes [4 + 2]-Diels-Alder cycloaddition with styrene to yield a flavan skeleton.
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