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The two-step approach for the synthesis of triborylalkenes starts with the conversion of terminal alkynes and pinacolborane (HBpin) into alkynylboronate catalyzed by a SiNN pincer ligand supported iridium complex, followed by treatment of the reaction mixture with CO for the generation of a new catalyst.

Two pairs of enantiomeric alkaloid dimers, (±)-macleayins A (1) and B (2), representing a novel dimerization pattern of two different types of alkaloids via a C-C σ-bond, were isolated from the aerial parts of Macleaya cordata. The enantiomeric separation was achieved by chiral chromatography. Their structures and stereochemistry were determined by the analysis of extensive spectroscopic data, electronic circular dichroism calculation, and single-crystal X-ray diffraction data. (-)-Macleayin A exhibits modest cytotoxic activity against HL-60 cell line with the IC50 value of 3.51 μM.

A new “single-flask” method was developed for the synthesis of imidazolidines and pyrrolidines with high stereoselectivity. First, a Schiff base was arylated with an aryne. Second, an intramolecular proton transfer took place from the methylene position to the anionic aryne ring. Third, the resultant ylide reacted with a second equivalent of the same Schiff base in situ or an electron-deficient alkene through a (3+2) cycloaddition. These sequential tandem 1,2-addition/(3+2) cycloaddition reactions led to the desired heterocycles in 63–88 % yields.

The domino reaction of ester-substituted Morita—Baylis—Hillman carbonates (I) with α-cyano-α,β-unsaturated ketones (II) and (IV) proceeds via α-selective cyclopropanation, ring-opening, and ring-closure cascade reactions to afford chiral tetrahydrofuropyranoindoles (III) and (V), respectively.

C1-Benzoyl isoquinolines can be generated via a palladium(II)-catalyzed C–C and C–O coupling of isoquinoline N-oxides with aromatic nitroalkenes. The reaction proceeds through remote C–H bond activation and subsequent intramolecular oxygen atom transfer (OAT). In this reaction, the N–O bond was designed as a directing group in the C–H bond activation as well as the source of an oxygen atom.

β-Acetoxy alcohols can be synthesized in good yields with excellent diastereoselectivity from tertiary alcohols through PhI(OAc)2-mediated metal-free β-acetoxylation. Mechanistic studies showed that the β-acetoxylation process might undergo dehydration and sequential highly regioselective and diastereoseletive dioxygenation. Gram scale and diverse useful scaffolds could be prepared via this β-acetoxylation process.

A general and efficient method for the direct alkynylation of unactivated C(sp3)–H bonds under metal-free conditions is described. The reaction performs smoothly under mild conditions and shows excellent functional-group tolerance. Initial mechanistic investigation indicates that the reaction may involve a radical pathway.

A remote OH group-directed metal-free transformation of alkynes to carbonyl compounds has been developed. Using only HOAc and EtOH solvent, this reaction elegantly converts alkynes into valuable ketones by remote hydroxyl group activation. Through comparison and isotope labeling experiments, it was confirmed that the process operates via a hydration reaction involving an acetic acid molecule, instead of a water molecule.

A novel strategy based on phase transfer catalysis for the diastereoselective and enantioselective direct assembly of unsymmetric β,β-diaryl-α-amino acid esters via 1,6-conjugate addition of para-quinone methides and glycine derivatives is described. This protocol also provides an alternative route to the synthetically interesting functionalized chiral tetrahydroisoquinoline and its analogues.

Copper-catalyzed three-component reactions of 2-iodoanilines, benzylamines, and sulfur powder are reported to afford benzothiazoles in a simple one-pot procedure by using water as solvent. A variety of 2-arylbenzothiazoles were obtained in moderate to good yields up to 88%.

Single-molecule magnets (SMMs) have attracted attention due to their potential applications in quantum computation and information storage, and many SMMs have been reported in the past two decades. In this review, we summarize the structures and the magnetic exchange interactions of pyridine alcohol-based SMMs to give a possible relationship between structure and magnetic property, providing information to generate new molecule-based magnetic materials. According to the correlated metal centers, these SMMs are separated into three segments to discuss.

β-Trifluoromethyl (CF3 ) enones were proved to act as good dienophiles in asymmetric normal-electron-demand Diels-Alder cycloadditions with 2,4-dienals under trienamine catalysis with a chiral secondary amine. The sequential reductive amination transformations with benzylamine produced cis- and trans-fused chiral trifluoromethylated octahydroisoquinolines in a diastereodivergent manner by using NaBH(OAc)3 and NaBH3 CN as the reductants, respectively. Moreover, other types of activated alkenes that bear a CF3 group have also been successfully utilized to construct a diverse range of chiral cyclic frameworks in high stereoselectivity.

The use of electron-poor, fluoro-containing arylboronic acids as general coupling partners for nickel(0) /tricyclohexylphosphine-catalyzed cross-coupling of aryl arenesulfonates is described. Electron-poor fluoro-containing arylboronic acids were found to react, faster than electron-rich/neutral arylboronic acids, with (4-methoxyphenyl)(4-methylbenzenesulfonato-κO)bis(tricyclohexylphosphine)nickel. Bis(1,5-cyclooctadiene)nickel(0)/tricyclohexylphosphine, (4-methoxyphenyl)(4-methylbenzenesulfonato-κO)bis(tricyclohexylpho sphine)nickel and bis(tricyclohexylphosphine)nickel (II) bromide were all found to be efficient catalysts/catalyst precursors.

Metal-based anticancer agents with non-DNA targets are anticipated for overcoming cisplatin resistance problems. Gold complexes are generally known to undergo ligand exchange or redox reactions with thiols, and hence, are potentially useful agents that could target thiol-containing enzymes, but not DNA. Recent studies have shown that deubiquitinases (DUBs), key enzymes regulating proteasome-related protein homeostasis, are potential anticancer targets of both gold(I) and gold(III) complexes. In this review, the current status of gold complexes as DUB inhibitors is discussed. In particular, auranofin and cyclometalated gold(III) complexes containing dithiocarbamate ligands (e.g., [(AuIII(C N)(DEDT)]+, HC N=2-phenylpyridine, DEDT=diethyldithiocarbamate) are highlighted as examples of DUB inhibitors. The mechanisms of their anticancer action, together with in vitro and/or in vivo antitumor potencies, are also explored.

A highly efficient and facile cobalt-catalyzed C–H activation and peroxidation of 2-oxindoles was reported, which provides a new pathway for the synthesis of biologically active 3-peroxy-2-oxindoles from readily available starting materials in excellent chemical yields. The resulting products could be further transformed into various substituted 3-peroxyoxindoles in good to excellent yields. The developed method has been successfully applied to the synthesis of the natural product (±)-N-[2-(3-hydroxy-2-oxo-2,3-dihydro-1H-indol-3-yl)ethyl]acetamide.

An unprecedented Ag(I)-catalyzed ligand-controlled stereodivergent 1,3-dipolar cycloaddition of azomethine ylides with 3-methyl-4-nitro-5-styrylisoxazoles has been developed to afford heterocycles bearing both methylisoxazole and pyrrolidine moieties. The endo- and exo-cycloadducts were obtained in good yields with excellent stereoselectivities, assisted by tBu-Phosferrox and phosphoramidite as chiral ligands, respectively.

The first intermolecular Schmidt reaction of alkyl azides with acyl silanes has been designed and realized, producing a range of amides with absolute site selectivity in good to excellent yields. The mechanism of the conversion has been proposed, and the reaction exhibits scope of substrates.

Iridium(III) complexes are one of the most important electrophosphorescent dyes with tunable emissions in the range of visible and near infrared lights, high photoluminescence yields and short lifetimes for high-efficiency organic light-emitting diodes (OLED) with 100% exciton harvesting. This review summarizes the recent development of electroluminescent Ir 3+ complexes functionalized with host-featured carrier-transporting groups, with emphasis on correlations between functionalization, optoelectronic properties and device performance. According to the introducing approaches, the complexes were sorted with conjugated and aliphatic linkages, as well as the types of functional groups. The modification effect on physical properties and the state-of-the-art device performances were discussed.

This review summarizes the recent progress of efficient room temperature phosphorescence (RTP) from pure organic luminogens achieved by crystallization-induced phosphorescence (CIP), with focus on the advances in our group. Besides homocrystals, mixed crystals and cocrystals are also discussed. Meanwhile, intriguing RTP emission from the luminogens without conventional chromophores is demonstrated.

A chiral iridium(I) N-heterocyclic carbene complex was reported for the first time as the catalyst in the highly enantioselective intramolecular allylic amination reaction. The current method provides facile access to biologically important enantioenriched indolopiperazinones and piperazinones in good yields (74-91 %) and excellent enantioselectivities (92-99 % ee). Preliminary mechanistic investigations reveal that the C-H activation occurs at the position ortho to the N-aryl group of the ligand.

A [Cp*Rh(III)]-catalyzed electrophilic amination of arylboronic acids with diethyl azodicarboxylate (DEAD) was developed, and arylhydrazides were produced in excellent yields and selectivity. The analogous amination with the arylazocarboxylates afforded the corresponding N,N-diarylhydrazides. The electrophilic amination of arylboronic acids with azocarboxylates proceeds readily under mild conditions with excellent functional group tolerance. Up to 99% yields were obtained. Preliminary mechanistic studies revealed that prior formation of an arylrhodium(III) intermediate for the azo coupling reaction can be ruled out.

Single crystals of the title compound are prepared by hydrothermal reaction of a 1:5 molar mixture of Bi2O3 and SeO2 in 40% aq.

The enantioselective N-heterocyclic carbene-catalyzed [2 + 4] cyclocondensation of α-chloroaldehydes and saccharine-derived 1-azadienes was developed, giving the corresponding saccharine-derived dihydropyridinones in good yields with exclusive cis-selectivities and excellent enantioselectivities.

A facile access to cis-dihydrofurobenzofuran from a Pd-catalyzed intramolecular oxidative C–O bond formation of 2-(2,5-dihydro-furan-2-yl)-phenol is reported. The combined use of Pd(OAc)2 as catalyst, acetonitrile as solvent and AgOAc or air as oxidant affords cis-dihydrofurobenzofurans in good (up to 83%) yields.

An Ir-catalyzed asymmetric synthesis of five-membered aza-spiroindolenines is achieved. Based on the detailed investigation of the reaction patterns of the aryl iminium migration, a one-pot asymmetric allylic dearomatization/migration sequence from racemic indole derivatives is realized, affording enantioenriched Pictet–Spengler-type products bearing an additional allylic stereogenic center adjacent to the C3 position of the indole core.

The dual character of benzoquinone is exploited for the synthesis of benzo[a]carbazole derivatives starting from 3-ethylindole derivatives. A diene is generated in situ from the 3-ethylindole derivative with the help of benzoquinone, where it acts as an oxidizing agent. Later it serves as a dienophile and participates in a Diels–Alder reaction with the diene to afford benzo[a]carbazole derivatives.

The process is found to form the desired carboxylic acids with complete (E) selectivity except for substrate (XV), where an E/Z mixture is identified.

An α-regioselective asymmetric [3 + 2] annulation reaction with Morita–Baylis–Hillman carbonates of isatins and (E)-2-nitro-1,3-enynes catalysed by cinchona-derived amines has been developed, providing spirooxindoles with contiguous chiral centres including adjacent quaternary ones in moderate to good yields with high enantioselectivity and excellent diastereoselectivity.

The unique electronic configuration and structural properties of ceria make ceria-based nanomaterials such as morphology-dependent ceria nanocrystals, rare earth-doped ceria-zirconia solid solutions and noble metal-ceria nanocomposites effective promoters in three-way catalysts for low-temperature water-gas-shift reaction, preferential oxidation of traces of CO, the treatment of toxic auto-mobile exhaust, etc. The activities of nanoceria catalysts can be determined by their morphologies, oxygen vacancies, interfacial structures and the type of exposed crystal surfaces, as well as the synergistic effect exhibited by nanocomposites. In this review, the state-of-the-art developments in the well-controlled synthesis of ceria-based nanocatalysts and their applications in both environmental and energy fields is summarized. The involved reaction mechanisms are also briefly introduced, and eventually an outlook in the design of novel nanoceria catalysts for valuable energy applications is addressed.

A transition metal-free and efficient method for the synthesis of 3-alkynylpyrrole-2-carboxylates from diynones and glycine esters or 2-aminoacetophenone hydrochloride has been developed. This transformation provides a large range of substituted pyrroles in good to excellent yields with the elimination of water as the only by-product. The detailed mechanistic studies elucidated that this transformation involves a Michael addition/intramolecular cyclodehydration process.

Hydroboration of conjugated enyne alcohol/amine is studied by using copper salts and bis(pinacolato)diboron as pre-catalysts and boron source respectively. It is suggested that the chemo-selectivity is derived from a combined electronic influence of the heteroatoms on the substrate and the ligand on the transition metal. The regioselectivity is probably dominated mainly by electronic effect of the alkyne substituent. This study resulted in a highly selective protocol to access Z,Z-/Z,E-1,3-dien-1/2-ylboronic ester bearing hydroxyl/amino group.

The asymmetric cross-hydroalkenylation of vinylarenes with terminal olefins in the presence of NiH complexes bearing various chiral N-heterocyclic carbenes (NHCs) is studied.

A simple method for preparation of per-O-trimethylsilylated amino sugars with unprotected amines is developed.

Dye-sensitized solar cells (DSSCs) are fabricated using low-cost materials and a simple fabrication process; these advantages make them attractive candidates for research on next generation solar cells. In this type of solar cell, dye-sensitized metal oxide electrodes play an important role for achieving high performance since the porous metal oxide films provide large specific surface area for dye loading and the dye molecule possesses broad absorption covering the visible region or even part of the near-infrared (NIR). Recently, metal-free sensitizers have made great progress and become the most potential alternatives. This review mainly focuses on recent progress in metal-free sensitizers for applications in DSSCs. Besides, we also briefly report DSSCs with near-infrared (NIR) organic sensitizers, which provide the possibility to extend the absorption threshold of the sensitizers in the NIR region. Finally, special consideration has been paid to panchromatic engineering, co-sensitization, a key technique to achieve whole light absorption for improving the performance of DSSCs.

The title compounds are screened for their activity against five human cancer cell lines and show significant cytotoxicity against HL-60 cells with IC50 values of 9.4 and 13.6 μM, respectively.

Depending on the solvent used, the efficient synthesis of either β-aryl enaminones (DMF) or 1,4,5-trisubstituted 1,2,3-triazoles (toluene) succeeds in a highly regioselective manner.

Two new β-carbolines, penipalines A and B (I), and the new indole carbaldehyde derivative, penipaline C (II) are isolated along with two known indole derived analogs from the deep-sea-sediment derived fungus Penicillium paneum SD-44 Compounds (Ib) and (II) exhibit potent cytotoxic activities against A-549 an HCT-116 cell lines.

The catalytic cyclocondensation of in situ activated α,β-unsaturated carboxylic acids was developed. N-heterocyclic carbenes efficiently catalyzed the generation of α,β-unsaturated acyl azolium intermediates from α,β-unsaturated carboxylic acids via in situ generated mixed anhydrides for the enantioselective [3+2] and [3+3] cyclocondensation with α-amino ketones and alkyl(aryl)imines, respectively. The corresponding pyrrolidinones and dihydropyridinones were isolated in good yields with high to excellent enantioselectivities.

A chemical investigation of Zoanthus kuroshio has yielded two new alkaloids, kuroshines A (1) and B (2). The compounds possess a densely functionalized ring system on the basis of the zoanthamine frames. The structures of 1 and 2 were elucidated through interpretation of spectroscopic methods, especially 2D NMR techniques (COSY, HMQC, HMBC, and ROESY). The absolute stereochemistry of 1 was further confirmed by an X-ray single crystallographic analysis using a mirror Cu-Kα radiation.

Selective oxidation of sulfides was successfully performed by employing phenyliodine diacetate as an oxidant with the catalysis of TsOH in aqueous solution under mild conditions. Sulfoxides were formed with 1.1 equiv of PhI(OAc)2 at room temperature; whereas sulfones were obtained in the presence of 2.1 equiv of PhI(OAc)2 at 80 °C under otherwise identical conditions. Notably, various sulfides were converted to corresponding sulfoxides or sulfones in good to high yields by this metal-free protocol.

A highly efficient Ag(I)-catalyzed atroposelective desymmetrization of N-(2-t-butylphenyl)maleimide via 1,3-dipolar cycloaddition of in situ generated azomethine ylides has been established successfully, affording a facile access to a series of biologically important and enantioenriched octahydropyrrolo[3,4-c]pyrrole derivatives in generally high yields (up to 99%) with excellent levels of diastereo-/enantioselectivities (up to 99% ee, >20:1 dr). Subsequent transformations led to fascinating 2H-pyrrole and polysubstituted pyrrole compounds without loss of stereoselectivity. The absolute configuration of the generated chiral axis has been unambiguously identified as (M) through single-crystal X-ray diffraction analysis. Furthermore, on the basis of the comprehensive experimental results and the absolute configuration of one of the cycloadducts, the origin of the stereoselectivity was proposed to be attributed to the steric congestion imposed by the bulky PPh2 group of the chiral ligand and the tert-butyl g...

Three unusual polyketide-sesquiterpene metabolites peyronellins A–C (1–3), along with the new epoxyphomalin analog 11-dehydroxy epoxyphomalin A (4), have been isolated from the endophytic fungus Peyronellaea coffeae-arabicae FT238, which was isolated from the native Hawaiian plant Pritchardia lowreyana. The structures of compounds 1–4 were characterized based on NMR and MS spectroscopic analysis. The absolute configuration (AC) of the compounds was determined by electronic circular dichroism (ECD). Compound 4 showed antiproliferative activity with an IC50 of 0.5 μM against OVCAR3, and it also strongly inhibited Stat3 at 5 μM.

SrWO4:Eu3 + nanowires with high aspect ratio were prepared by a solvothermal method via a poor solvent induced self-assembly process. The luminescence properties of SrWO4:Eu3 + nanowires were investigated in detail. In the emission spectrum excited at 277 nm, the 5D0 → 7F2 is much stronger than the 5D0 → 7F1, indicating that Eu3 + ions occupy low symmetry sites in SrWO4 lattices. The broad excitation band centered at 277 nm is assigned to the overlap of WO42 − absorption and charge transfer transition between Eu3 + and O2 −. The temperature-dependent luminescent properties are also investigated in a wide temperature range from 100 to 450 K, it reveals that SrWO4:Eu3 + is a potential luminescent thermometer in the temperature range from 310 K to 450 K.

An enantioselective In(OTf)3-catalyzed allylation of ketimines derived from isatins in the presence of an imidazolylpyridine ligand is described. The reaction proceeded smoothly under mild conditions and resulted in 3-allyl 3-aminooxindoles with good yields and moderate to excellent enantioselectivities (up to 97% ee).

A simple and highly efficient protocol has been developed for the Pd/C-catalyzed ligand-free Suzuki–Miyaura reaction of potassium aryltrifluoroborates. In this catalytic system, the results demonstrate that oxygen plays a positive role in the cross-coupling reaction. In addition, this catalytic system could be successfully applied to synthesize biaryl compounds containing a carbazole moiety and the catalyst was recycled seven times without significant loss of catalytic activity.

In searching for more bioactive compounds, phytochemical investigations on the acetone extract of the leaves of Nicotiana tabacum resulted in the isolation of two new sesquiterpenes, nicosesquiterpene A and B ( 1 and 2 ), along with four known sesquiterpene derivatives ( 3–6 ). Structural elucidation of 1 and 2 was performed by spectral methods, such as HRMS, IR, UV, 1D and 2D NMR spectroscopy. Compounds 1 and 2 are the first naturally occurring pterosin-type sesquiterpene bearing an isopropyl moiety. Compounds 1–6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 exhibited high anti-TMV activity with inhibition rates of 36.7% and 45.6%, respectively, which is higher than that of positive control. The other compounds also showed potential activity with inhibition rates in the range of 22.7%–29.2%.