An efficient triflic anhydride promoted phosphorylation of ketone was disclosed, and vinylphosphorus compounds were prepared under solvent- and metal-free conditions. Both aryl and alkyl ketones could perform smoothly to give vinyl phosphonates in high to excellent yields. In addition, the reaction was easy to carry out and easy to scale up.
View Article and Find Full Text PDFAn addition of H-phosphonates to aryl alkynes was realized under solvent- and metal-free conditions, affording Markovnikov-selective α-vinylphosphonates in moderate to good yields. A wide range of aryl alkynes could be applied for the reaction. A tentative mechanism of addition-substitution was proposed based on P {H} NMR studies.
View Article and Find Full Text PDFOvarian cancer (OC) is one of the most aggressive female cancers in the world. OC trends to be diagnosed at an advanced stage with abdominal metastasis. Our study explored the biological function and underlying mechanism of lncRNA on OC cell proliferation and migration.
View Article and Find Full Text PDFOpen-cage fullerenes with a 19-membered orifice were prepared in three steps from C . The key step for cage-opening is aniline mediated ring expansion of a fullerene-mixed peroxide with a ketolactone moiety on the orifice. Release of ring strain on the spherical fullerene cage served as the main driving force for the efficient cage-opening sequence.
View Article and Find Full Text PDFResulting from the drastic increase of atmospheric CO concentration day by day, global warming has become a serious environmental issue nowadays. The fixation of CO to obtain desirable, economically competitive chemicals has recently received considerable attention. This work investigates the fixation of CO along with three bromopyridines via a facile electrochemical method using a silver cathode to synthesize picolinic acids, which are important industrial and fine chemicals.
View Article and Find Full Text PDFA series of bibenzo[ b][1,4]thiazines with various functional groups has been synthesized by a free-radical condensation reaction. Bibenzo[ b][1,4]thiazines were obtained in moderate to good yield (up to 85%) through a one-step reaction of readily available 2,2'-dithiodianiline and methyl aryl ketones with AIBN as radical initiator in HOAc. Bibenzo[ b][1,4]thiazines exhibit diversiform solid-state packing.
View Article and Find Full Text PDFA novel metal-free one-pot protocol for the effective and efficient synthesis of 3-phosphinoylbenzofurans via a phospha-Michael addition/cyclization of H-phosphine oxides and in situ generated ortho-quinone methides is described. Based on the expeditious construction of C(sp)-P bonds, asymmetric synthesis of optically pure 3-phosphinoylbenzofurans containing chiral P-stereogenic center has also been probed by using chiral R-(-)-menthyl phenylphosphine oxide.
View Article and Find Full Text PDFBy the combination of Pd-complexes and [VO], three Pd-decavanadate compounds [Pd(NH)][VO]·8HO (1), [Pd(deta)(HO)](NH)[VO]·2HO (2) (deta = diethylenetriamine) and [Pd(dpa)](Hdpa)(EtNH)[VO]·2HO (3) (dpa = 2,2'-dipyridylamine) have been successfully synthesized and thoroughly characterized using single X-ray diffraction (SXRD), powder X-ray diffraction (PXRD), infrared spectroscopy (FT-IR) and elemental analyses (EA). Interestingly, in the three compounds, the molar ratios of Pd to decavanadate vary from 3 : 1 to 1 : 1 by changing N-ligands. The three Pd-decavanadates as heterogeneous catalysts are active in the aerobic oxidation of benzylic hydrocarbons under solvent-free conditions without adding any additives and co-catalysts.
View Article and Find Full Text PDFAn open-cage C derivative 9 with anilino, hemiketal, and lactone moieties on the edge of the opening was prepared through a fullerene-mixed peroxide procedure. Key steps include decarbonylation, intramolecular Friedel-Crafts reaction and oxetane ring opening rearrangement. The open-cage compound 9 readily reacts with various metal salts.
View Article and Find Full Text PDFP,C-stereogenic 1,3-bisphosphinylpropanes 3 that have up to five stereogenic centers could be obtained stereoselectively in high yields by a one-step reaction of (RP)-menthylphenylphosphine oxide 1 with α,β-unsaturated aldehydes 2 catalyzed by KOH at room temperature. A mechanism was proposed as to involve a stereoselective intermolecular 1,3'-phosphorus migration from the 1,2-adduct of 1 with 2 to another 2 generating a 1,4-adduct that subsequently reacts with 1 to produce 3.
View Article and Find Full Text PDFAromatic methyl ketones and cyclic asymmetric ketones underwent hydrophosphorylation with P-stereogenic H-P species in the presence of potassium carbonate to produce P,C-stereogenic tertiary α-hydroxyl phosphinates in excellent yields with up to 99 : 1 dr. The diastereoselectivity was induced by a reversible conversion of less stable stereomer of product to that of a more stable one via an equilibrium, which was confirmed by aldehyde/ketone exchanging reaction. Toward the exchange, aliphatic or aldehyde carbonyl were more active than aromatic or ketone carbonyls, respectively.
View Article and Find Full Text PDFFour isomers are currently known for the trioxygenated fullerene derivative C(60)(O)(3), three regioisomers with all of the oxygen addends as epoxy groups and the unstable ozonide isomer with a 1,2,3-trioxlane ring. Here we report the synthesis of an open-cage isomer for C(60)(O)(3) with a ketolactone moiety embedded into the fullerene skeleton through a three-step procedure mediated by fullerene peroxide chemistry. Two fullerene skeleton carbon-carbon bonds are cleaved in the process.
View Article and Find Full Text PDFA series of isomerically pure alkynyl-substituted fullerenol derivatives such as C(60)(OH)(6)(O(CH(2))(3)CCH)(2) were synthesized through Lewis acid catalyzed epoxy ring opening and/or S(N)1 replacement reactions starting from the fullerene-mixed peroxide C(60)(O)(t-BuOO)(4). Copper-catalyzed azide-alkyne cycloaddition readily converted the terminal alkynyl groups into triazole groups. Intramolecular oxidative alkyne coupling afforded a fullerenyl crown ether derivative.
View Article and Find Full Text PDFBromine reacts with the 1,2-bisadduct C(60)(OOtBu)(2) efficiently to form the cyclopentadienyl-type compound 4 (C(60)(OOtBu)(2)Br(4)). In the presence of AgClO(4), the four bromine atoms can be replaced regioselectively by methoxyl groups in a stepwise fashion to form C(60)(OOtBu)(2)Br(4-x)(OMe)(x). A second alcohol may be introduced by treating partially methoxylated compound 6 (C(60)(OOtBu)(2)Br(2)(OMe)(2)) with ROH/AgClO(4).
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