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Three rare carbamate-containing alkaloids, penicimutamides A–C (1–3), were isolated from a fungal mutant from the diethyl sulfate (DES) mutagenesis of marine-derived Penicillium purpurogenum G59. Their structures, including their absolute configurations, were determined by spectroscopic methods, especially the X-ray crystallography and CD analyses. HPLC-UV and HPLC-MS analyses evidenced that 1–3 were only produced in the mutant strain via biosynthetic pathways that were silent in the parental strain and activated by DES mutagenesis.

It is important to find a way for separation of concerned chemicals from product mixture after reaction, in order to avoid spreading harmful chemicals to society. The homogeneous nature of DMAP-catalyzed acylation still suffers from the problems of catalyst separation and/or residual DMAP contamination. DMAP causes acute dermal toxicity, whereas the corresponding DMAP salt exhibits only slight irritation to the skin. Very recently, we found that the DMAP saccharinate salt is also great recyclable catalyst, whose acylation of alcohols has been successfully and effectively carried out 10 times without loss in activity. This report covers our comprehensive studies on using the pyridinium saccharinate salts as efficient recyclable acylation catalysts including 4-N,N-dimethylaminopyridinium saccharinate (A), 4-(1-pyrrolidinyl) pyridinium saccharinate (B), 2-N,N-dimethylaminopyridinium saccharinate (C), and pyridinium saccharinate (D). Their structure and reactivity have been studied. The salts A, C, and D contain very interesting seven-membered synthon showing multiple H-bonding interactions for pair of pyridinium cation and saccharinate anion in the solid state. The salt B exhibits H-bonding interaction of N(sac) … H–N(py) in the solid state, instead of seven-membered synthon. The catalytic reactivity studies show that salts A and B are both very effective, with salt B even better in reactivity, and are both recyclable in the esterification of a variety of alcohols, under solvent-free and base-free conditions at room temperature.

Indolyl methanol derivatives undergo an efficient dehydrative SN1-type reaction with a variety of nucleophiles using water as the solvent, affording versatile 3-indolyl derivatives in high yields.

This paper describes an efficient SN1-type reaction of 3-indolylmethanols with miscellaneous nucleophiles, featuring a catalyst-free procedure, low cost, wide substrate scope and mild reaction conditions. This approach provides green and efficient methods for the synthesis of diverse 3-substituted indolyl derivatives as well as unsymmetrical bisindolylmethanes and triarylmethanes.

A pair of new enantiomeric alkaloid dimers, (+)- and (−)-pestaloxazine A (1), with an unprecedented symmetric spiro[oxazinane-piperazinedione] skeleton, consisting of 22 carbons and 12 heteroatoms, were isolated from a Pestalotiopsis sp. fungus derived from a soft coral. Separation of the enantiomeric alkaloid dimers was achieved by chiral HPLC. Their structures including absolute configurations were elucidated on the basis of a comprehensive analysis of their spectroscopic and X-ray diffraction data and CD calculations. (+)-Pestaloxazine A exhibited potent antiviral activity against EV71 with an IC50 value of 14.2 ± 1.3 μM, which was stronger than that of the positive control ribavirin (IC50 = 256.1 ± 15.1 μM).

Bioassay-guided fractionation of an AcOEt-soluble fraction of the liquid fermentation of an endophytic fungus Hypoxylon sp. BCRC 12F0687 associated with the root of Taiwanese Ilex formosana (Aquifoliaceae) resulted in the isolation of two new compounds, i.e., one benzenoid, hypoxyphenone (1), and one azaphilone derivative, hypoillexidiol (2), two metabolites isolated for the first time from natural source, (−)-(3S)-3-hydroxy-3-methyloxindole (3) and (+)-vermelone (4), along with twelve previously identified compounds, 5–16. Their structures were determined through in-depth spectroscopic and mass-spectrometric analyses. The effects of some isolates on the inhibition of NO and IL-6 production in lipopolysaccharide-activated RAW 264.7 murine macrophages were evaluated. Of the isolates, 2 and 3 exhibited potent anti-NO production activity, with IC50 values of 17.5±1.8 and 24.7±1.6 μM, respectively, compared to that of quercetin, an iNOS inhibitor with an IC50 value of 35.9±1.7 μM. Compounds 2, 4, 5, and 12 also showed moderate inhibition of IL-6 production, with IC50 values ranging from 27.2±1.8 to 35.3±5.8 μM. This is the first report on an oxindole metabolite from the genus Hypoxylon.

One new merosesquiterpenoid, craterellin D (1), along with one known analog, craterellin A (2), and five known ten-membered macrolides, 3-7, were isolated from a soft coral-derived Lophiostoma sp. fungus. The absolute configuration of 1 was established based on biogenetic consideration with the co-isolated analog 2, whose configuration was determined by modified Mosher's method and single-crystal X-ray diffraction analysis using CuKα radiation. The absolute configuration of 3 was determined by X-ray diffraction analysis using CuKα radiation. Compounds 2 and 3 showed antibacterial activities against Bacillus cereus with a MIC value of 3.12 μM.

Three new diphenyl ether derivatives, talaromycins A—C, are isolated together with six known analogues and evaluated for their cytotoxic and antifouling activities.

Eleven new scalarane sesterterpenoids, including three 20,24-bishomo-25-norscalaranes, carteriofenones A–C (1–3), and eight 20,24-bishomoscalaranes, carteriofenones D–K (4–11), along with two known analogues (12 and 13), were obtained from the marine sponge Carteriospongia foliascens collected from the South China Sea. Their planar structures and relative configurations were elucidated by extensive NMR spectroscopic data. The absolute configuration of 3 was determined using the modified Mosher's method on its hydrolysis product. Scalarane sesterterpenoids with 4-methylpentanate or pentanoate substituents at the 12-position (1–8) were reported for the first time. Carteriofenones E–H (5–8) represented rare naturally occurring scalarane sesterterpenoids with a cyclobutane ring. Compound 4 showed cytotoxicity against the mouse lymphocytic leukemia cell line (P388) with an IC50 value of 0.96 μM.

Two new labdane-type diterpene acids, (12S)-12-hydroxylabda-8(17),13(16),14-trien-18-oic acid (1) and (12R)-12-hydroxy-15,16-epoxylabda-8(17),13-dien-18-oic acid (2), along with a known labdane-type diterpene, (11E)-15,16-bisnor-13-oxolabda-8(17),11-dien-19-oic acid (3), were isolated from the MeOH extract of the wood of Cunninghamia konishii. Their structures were determined by analysis of spectroscopic data and comparison with the data of known analogs.

isolation and structure of two new compounds, 1β,7α-dihydroxyeudesman-4-one (I) and 5αH-megastigm-7-ene-3α,4α,6.beta,9-tetrol (II), along with nine known terpenoids

The cytotoxic activities of (I) and (II) are evaluated showing that (II) has medium antiproliferative activity.

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.

isolation and structure determination of a new abietane diterpene, named abietopinoic acid (I), and a new podocarpane diterpene, podopinoic acid (II)

New brominated title compounds (I) are isolated together with four known non-brominated analogues.

isolation, structure and cytotoxicity of five new secosteroids (I) and seven known analogues

A diverse library of novel carbamates was synthesized utilizing copper-catalyzed oxidative C–O coupling of formamides and salicylaldehydes. Sensitive aldehyde groups remained intact in the presence of an oxidant and a transition-metal salt. Salicylaldehydes bearing electron-donating, electron-withdrawing, and halogen groups as well as 1-hydroxy-2-naphthaldehydes provided the desired carbamates in good to excellent yields.

A simple iron carbonyl catalyzed method for the α-selective aryloxylation of cyclic ethers is developed using a variety of salicylic aldehydes as phenol derivative and tBuOOH as the oxidant.

A convenient synthetic route for the construction of functionalized 2-cyano-1,4-diketones has been established from the nucleophilic substitution of 2-bromoacetophenones with NaCN via the in situ-generated β-ketonitriles. This method was further applied to the synthesis of cyanosubstituted furans, pyrroles, or dihydropyridazines, which were obtained in good to excellent yields using Bi(OTf)3, NH4OAc, or N2H4. The key structures were confirmed by X-ray single crystal diffraction analysis.

The difluoromethylation of N-arylsulfonyl hydrazones with difluorocarbene generated from difluoromethylene phosphobetaine (Ph3P+CF2CO2−) to give various difluoromethyl aryl sulfones is described.

Gold-catalyzed C-heteroatom (C–X) coupling reactions are evaluated without using sacrificial oxidants. Vital to the success of this methodology is the nucleophile-assisted activation of aryldiazonium salts, which could be an effective oxidant for converting Au(I) to Au(III) even without the addition of an assisting ligand or photocatalyst. By accelerating the reaction kinetics to outcompete C–C homo-coupling or diazonium dediazoniation, gold-catalyzed Sandmeyer reactions were achieved with different nucleophiles, forming C–Br, C–S and C–P bonds in high yields and selectivities.

Three new abietane-type diterpenoids, 7β-acetoxy-12-methoxyabieta-8,11,13-triene-6α,11-diol (1), 7α-acetoxy-12-methoxyabieta-8,11,13-triene-6α,11-diol (2), and 6α-acetoxy-12-methoxyabieta-8,11,13-triene-7α,11-diol (3), as well as two known abietane-type diterpenoids, 12-methoxyabieta-8,11,13-triene-6α,7β,11-triol (4) and 6α-acetoxy-12-methoxyabieta-8,11,13-triene-7β,11-diol (5), were isolated from the MeOH extract of the bark of Cryptomeria japonica. Their structures were determined by analysis of spectroscopic data and comparison of NMR data with those of related metabolites.

Single phase CuSbSe2 crystallites are prepared by hot injection of a solution of Cu(OAc)2 and Sb(OAc)3 in triethylene glycol (TEG) into a solution of Se in TEG as both the solvent and reducing agent as well as different amounts of triethylenetetramine (TETA) as co-reducing agent (250 °C, various periods; cooling to 60 °C and termination of the reaction by injecting EtOH).

2-Cyclopentenone derivatives have been efficiently synthesized from 5-bromo-5-hexen-2-ones via palladium-catalyzed intramolecular carbonyl α-alkenylation followed by double-bond migration under mild reaction conditions.

We report on a facile synthetic route for the preparation of substituted 1,4-diketones by thulium triflate mediated hydration of substituted 4-alkynones in MeNO 2 at 25 °C for five hours. The products were obtained in moderate to high yields.

α-Amino phosphinates with P , C -stereogenic centers were prepared from a P -retained addition of ( R P )-(−)-menthyl H -phenylphosphinate to ( R )-aldimines with up to 86:14 dr under catalyst and solvent free condition at ambient temperature; the single ( S P , S α-C )-stereoisomers were isolated in moderate yields. Chirality on the nitrogen of chiral aldimine was proposed to control the stereoselectivity, and the (−)-menthoxyl showed mismatched asymmetric induction with ( S )-aldimines.

An efficient transition-metal-free fluoroarylation reaction of N-aryl diazoacetamides with NFSI (N-fluorobenzenesulfonimide) is described. This reaction directly provides 3-fluorooxindole derivatives in yields of 67–93% with high selectivity via a carbene-free process under mild reaction conditions.

The title compound (II), a key intermediate for the synthesis of the anti-psychotic drug olanzapine, is prepared by intramolecular cyclocondensation of [(nitrophenyl)amino]thiophenecarbonitrile (I) using tin powder and HCl a reducing system.

An efficient protocol for the synthesis of highly functionalized furans via intramolecular Wittig reaction has been developed using catalytic amounts of phosphine and triethylamine. Silyl chloride served as the initial promoter to activate the phosphine oxide. Reduction of the activated phosphine oxide by hydrosilane resulted in generation of phosphine, while decomposition of Et3N·HCl resulted in regeneration of base, which mediated formation of phosphorus ylide. Remarkably, the in situ generated byproduct, Et3N·HCl, also catalyzes reduction of phosphine oxide.

An iodine mediated intramolecular C—H amination of N-2-pyridyl substituted electron rich anilines is developed to produce pyrido[1,2-a]benzimidazoles in good yields, in general.

Unique imidoylation of thioorganics with isocyanides endows an unprecedented aerobic oxidation process. Catalyzed by Pd(Ph3P)2Cl2 in the presence of Ph3SiH under N2 then upon exposure to air, a wide range of α-acyl ketene dithioacetals react with isocyanides to afford 5-hydroxy-α,β-unsaturated γ-lactams via a C–S bond activation, isocyanide migratory insertion, hydrogenation, selective aerobic oxidation, and intramolecular nucleophilic addition sequence.

A four-component Ugi reaction (Ugi-4CR) utilizing formylphenyl boronic acids under mild condition was developed for the synthesis of arylboronic acid analogs. The reactions were performed in methanol and accelerated by microwave irradiation, which makes this strategy suitable for constructing boronic-containing chemical libraries. Two of the synthesized analogs were found to have cytotoxic activity against HepG2, MDA-MB231, and A549 cancer cell lines, demonstrating the potential application of this approach in developing novel boron-containing pharmaceuticals.

We present a metal-free [2 + 2 + 2] cycloaddition of ynamides with nitriles that enables highly efficient access to 2,4-diaminopyridines. This catalytic protocol is more environmentally friendly and allows for a concomitant construction of C–C and C–N bonds between ynamides and nitriles, exhibiting excellent chemoselectivity, regioselectivity, and wide functional groups tolerance.

Polycrystalline K2Ti8O17 is prepared by hydrothermal reaction of (BuO)4Ti and KOH in a 1:1 mixture of ethylene glycol and H2O (autoclave, 200 °C, 20 h) followed by calcination in air (700 °C, 12 h).

Under control of a chiral Bronsted acid catalyst, racemic indolines undergo intramolecular Povarov reactions with achiral aromatic aldehydes bearing a pendent dienophile. One enantiomer of the indoline reacts preferentially, resulting in the highly enantio- and diastereoselective formation of polycyclic heterocycles with four stereogenic centers. This kinetic resolution approach exploits the differential formation/reactivity of diastereomeric ion pairs.

Copper is an essential element in biological systems. Its potent redox activity renders it necessary for life, but at the same time, misregulation of its cellular pools can lead to oxidative stress implicated in aging and various disease states. Copper is commonly thought of as a static cofactor buried in protein active sites; however, evidence of a more loosely bound, labile pool of copper has emerged. To help identify and understand new roles for dynamic copper pools in biology, we have developed selective molecular imaging agents for this metal, drawing inspiration from both biological binding motifs and synthetic model complexes that reveal thioether coordination as a general design strategy for selective and sensitive copper recognition. In this review, we summarize some contributions, primarily from our own laboratory, on fluorescence- and magnetic resonance-based molecular-imaging probes for studying copper in living systems using thioether coordination chemistry.

Colorless block-shaped crystals of the title compound are prepared from aqueous solutions of Mn(NO3)2, NaN3, and cyclohexylamine hydrochloride (room temperature, 2 d, 50% yield).

Phosphonium salt ([Ph3P(+)CF2H] Br(-), DFPB) was found to be an efficient nucleophilic difluoromethylation reagent. Although DFPB is known as a phosphonium ylide precursor, its reaction with carbonyl compounds under traditional "Wittig reaction conditions" did not give the expected Wittig difluoroolefinated products, but afforded the nucleophilic difluoromethylation products, α-CF2H alcohols. Mechanistic investigation reveals that the unexpected transformation proceeded via the direct transfer of the CF2H group, which resulted from the high P-O affinity.

Idelalisib ((S)-5-fluoro-3-phenyl-2-[1-(9H-purin-6-ylamino)-propyl]-3H-quinazolin -4-one, 9) is the first-in-class, highly selective inhibitor of phosphoinositide 3-kinase p110δ; it has been clinic...

A facile and efficient approach to access 1,2,4-triazolo[4,3-a]pyridines and related heterocycles has been accomplished through condensation of readily available aryl hydrazines with corresponding aldehydes followed by iodine-mediated oxidative cyclization. This transition-metal-free synthetic process is broadly applicable to a variety of aromatic, aliphatic, and α,β-unsaturated aldehydes, and can be conveniently conducted on the gram scale.

The novel allenylphosphinates containing up to three axial and phosphorus asymmetric centers were prepared in excellent yields via the reactions of 6-chloro-6H-dibenzo[c,e][1,2]oxaphosphinine to propargyl alcohols. During the process, the configuration of phosphorus determined the biphenyl axial chirality, stereospecifically forming (l)-stereomers but did not influence the chirality of allenyl axis.

Phosphine-catalyzed [2 + 4] annulation of allenoates with thiazolone-derived alkenes has been achieved under mild conditions, giving biologically important 6,7-dihydro-5H-pyrano[2,3-d]thiazole derivatives in high to excellent yields. With the use of Kwon’s phosphine as the chiral catalyst, optically active products were obtained in good yields with excellent enantioselectivities.

[Me2NH2]2Na11 [X2W21NaO72(OH)2] ·34H2O (X: SbIII (I), BiIII (II)) are prepared by a one-pot self-assembly of aqueous solutions of Na2WO4, NaOAc, and Me2NH2Cl to which a HCl solution of SbCl3 (or Bi(NO3)3 and Zr(NO3)4 for (II)) is added dropwise.

Sodium amalgam mediated desulfonylative reduction of β-ketosulfones in MeOH at rt affords alcohols in good yields via radical desulfonylation of β-ketosulfones and sequential Bouveault-Blanc reduction of the resulting ketones.

A novel method for the formation of indole derivatives via gold-catalyzed tandem reactions of 2-alkynyl arylazides and oxygen-containing heterocycles has been developed. A variety of indole derivatives were prepared under mild reaction conditions.