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The activation and cleavage of benzyl fluorides by the electrophilic organofluorophosphonium catalyst, [(C6F5)3PF][B(C6F5)4], is reported and used for the preparation of 1,1-diarylalkanes (37 examples) and substituted aryl homoallylic alkenes (14 examples). This procedure involves mild conditions, avoids harmful waste, and is compatible with a range of substituted arenes and allylic silanes.

Single crystals of Sr0.5CuZrSe3 (I), Ba0.5CuZrSe3 (II), SrCuYSe3 (III), and BaCuYSe3 (IV) are prepared by solid state reactions of stoichiometric amounts of Cu or Cu2Se (in case of (III)), Ba or BaSe (in case of (II)), and the remaining elements (sealed silica ampoules, 1.

A protocol for effecting a rapid Saegusa-type oxidation of enol acetates is reported. This new method relies on the in situ elimination of an α-bromo intermediate to generate α,β-unsaturated ketones using copper(II) bromide. The methodology developed was applied to a range of substrates including a cyclohexanone, which could be directly converted to the corresponding phenol derivative. A catalytic system in which a non-masked ketone was successfully oxidised using substoichiometric CuBr2 was also developed as a proof of principle.

Zinc reagents (Me2PhSi)2Zn and [(Me3Si)3Si]2Zn undergo highly regio- and stereoselective addition across the carbon–carbon triple bond of nitrogen-, sulfur-, oxygen-, and phosphorus-substituted terminal alkynes in the absence of copper or any other catalyst. Both reagents yield exclusively β-isomers, and the stereoselectivity is determined by the silyl group: Me2PhSi for cis or (Me3Si)3Si for trans. These stereodivergent silylzincation protocols offer an efficient access to heteroatom-substituted vinylsilanes with either double bond geometry, including trisubstituted vinylsilanes by one-pot electrophilic substitution of the intermediate C(sp2)–Zn bond by copper(I)-mediated carbon–carbon bond formation.

The use of tert-butanesulfinamides as nitrogen nucleophiles in carbon-nitrogen bond forming reactions is reviewed. This field has grown in the shadow of the general interest in N-tert-butanesulfinyl imines for asymmetric synthesis and occupies now an important place in its own right in the chemistry of the chiral amine reagent tert-butanesulfinamide. This article provides an overview of the area and emphasizes recent contributions wherein the tert-butanesulfinamides act as chiral auxiliaries or perform as nitrogen donors in metal-catalyzed amination reactions.

Six new polyketide derivatives, including pestalpolyol I (1), pestapyrones A (2) and B (3), (R)-periplanetin D (6), pestaxanthone (7), norpestaphthalide A (8), and an isolation artifact pestapyrone C (4), were obtained from extracts of the endophytic fungus Pestalotiopsis clavispora isolated from the Mangrove plant Rhizophora harrisonii. In addition, seven known metabolites, including similanpyrone B (5), (R,S)-5,7-dihydroxy-3-(1-hydroxyethyl)phthalide (9), for which we propose the trivial name norpestaphthalide B, pestaphthalides A (10) and B (11), 2-epi-herbarumin II (12), and pestalotiollides A (13) and B (14) were isolated. The structures of the new compounds were unambiguously elucidated on the basis of one- and two-dimensional NMR spectroscopy, as well as by high-resolution mass spectrometry. All compounds were tested for their cytotoxicity against the mouse lymphoma cell line L5178Y. Compound 1 exhibited strong activity with an IC50 value of 4.10 μM. All other compounds (2–14) proved to be inactive (IC50 >10 μM) in this assay.

Herein an extremely versatile, well-defined, low-valent cobalt catalyst [Co(PMe3)4] capable of intermolecular and intramolecular imine-directed C2-alkylation and alkenylation of indoles is reported. The reaction proceeds in the absence of reducing agents or additives, affording a range of substituted indoles and dihydropyrroloindoles in high yields and regioselectivities. With the aid of deuterium labeling studies and DFT (Density Functional Theory) calculations, a mechanism is proposed that is based on a Ligand-to-Ligand Hydrogen Transfer pathway.

The asymmetric 1,6-conjugate addition of arylboronic acids to natural securinine under rhodium(I) catalysis displays a very high regioselectivity, along with a remarkable diastereoselectivity (>99:1) and high yields. The in vitro cytotoxicity of the resulting securinine analogues was assayed against HCT-116 colon cancer cells, giving a new insight into the structure–activity relationship of securinine.

The polyketide natural product cryptocaryol A (I) is prepared in 8 steps via iridium catalyzed enantioselective diol double C—H allylation, which directly generates an acetate-based triketide stereodiad.

Since the discovery of the giant magnetocaloric effect (MCE) close to room temperature in FeRh and particularly in Gd5Si2Ge2 compounds, the study of this phenomenon has experienced an exponential growth. Among the different techniques used to produce magnetocaloric materials, ball milling has been shown as a very versatile one and presents several advantages over other preparation techniques (e.g., easy scale-up to industrial production). Although a general decrease of the peak value of the magnetic entropy change is observed for milled samples, it can be compensated by the large broadening of the MCE peak, leading to an increase of the refrigeration capacity. In this short review, several aspects inherent to powder samples affecting MCE will be discussed, such as the relevant effect of the demagnetizing field, the possible multiphase character, and the presence of Curie temperature distributions. In mechanically alloyed samples, the two latter factors are typically affected by the degree of integration of the different starting constituents.

Aryl and alkyl CF3 groups are converted into CH2-aryl fragments upon treatment with arenes in the presence of the reagents/catalyst combination under conditions A).

Ruthenium(0) complexes modified by CyJohnPhos or RuPhos catalyze the successive C-C coupling of acetylenic aldehydes with α-ketols to form [4+2] cycloadducts as single diastereomers. This method enables convergent construction of type II polyketide ring systems of the angucycline class.

A modular entry to enantiopure (E)-2-substituted 3-alkylideneprolines is disclosed in 5 or 6 steps from tert-butanesulfinamide.

A convenient and general asymmetric transfer hydrogenation of a wide array of 1-aryl-3,4-dihydroisoquinoline derivatives using a [RuIICl(η6-benzene)TsDPEN] complex in combination with a 5:2 HCOOH–Et3N azeotropic mixture as a hydrogen source was developed. Under mild reaction conditions, the described catalytic transformation secured a practical synthetic access to the corresponding valuable chiral 1-aryltetrahydroisoquinoline units with high atom economy, a broad substrate scope, high isolated yields (up to 97 %) and good to excellent enantioselectivities (up to 99 % ee). It was found that the stereochemical outcome of the reaction was strongly influenced by both the structure of the catalyst and the substituents present on the substrate. The synthetic utility of the present protocol has been demonstrated through the asymmetric synthesis of several biologically important alkaloids including the antiepileptic drug agent 1c, as well as (–)-nor-cryptostyline alkaloids I and II.

The hydrogenation of olefins is achieved using a combination of phoshorous(V)-based Lewis acids with diaryl amines for the activation of dihydrogen.

Polycrystalline Ba0.5Cr5Se8 is prepared from a stoichiometric mixture of BaSe, Cr, and Se (alumina boat in sealed silica tube, 873 K, 2 d).

We report here an improved, highly efficient, and general method for the ligand-free Suzuki cross-coupling reaction to the synthesis of biaryls, bipyridyls, thienylpyridine, and allylphenols. Microwave irradiation of (het)aryl halides and (hetaryl, allyl)arylboronic acid N-methyl-iminodiacetic acid (MIDA) ester, using polyurea microencapsulated palladium catalyst (Pd EnCat 30), gave the coupling adducts 1a–x in excellent yields in just 10–18 min.

Electrophilic phosphonium cations (EPCs) are efficient main group catalysts for the hydroarylation of olefins under mild conditions, providing a facile route to substituted aniline, bis-arylamine, phenol, furan, thiophene, pyrrole, and indole derivatives. Similarly, EPCs catalyze the hydrothiolation of aryl olefins with thiophenol affording a series of alkyl aryl thioethers. Experimental data support a mechanism for these reactions that involves initial activation of the olefin.

Ketones are efficiently deoxygenated in the presence of silane using highly electrophilic phosphonium cation (EPC) salts as catalysts, thus affording the corresponding alkane and siloxane. The influence of distinct substitution patterns on the catalytic effectiveness of several EPCs was evaluated. The deoxygenation mechanism was probed by DFT methods.

Upon exposure of 3,4-benzannulated 1,5-diynes (benzo-endiynes) to α-ketols (α-hydroxyketones) in the presence of Ru(0) catalysts derived from Ru3(CO)12 and RuPhos or CyJohnPhos, successive redox-triggered C–C coupling occurs to generate products of [4 + 2] cycloaddition. The proposed catalytic mechanism involves consecutive alkyne-carbonyl oxidative couplings to form transient oxaruthanacycles that suffer α-ketol mediated transfer hydrogenolysis. This process provides a new, convergent means of assembling Type II polyketide substructures.

Ba4Fe3Se10 (I) and BaFe2Se4 (II) are prepared from stoichiometric amounts of the elements (evacuated silica tubes, 700 °C, 2 d).

Single crystals of CaOFeS are prepared by solid state reaction of CaO, iron, and sulfur in a 1:1:1 ratio (alumina crucible, 950 °C, 12 h).

Review: some of the most relevant synthetic procedures reported up to date, with a special focus on synthetic routes to nonfunctionalized gold nanoparticle in aqueous media, influence of synthesis conditions on the shape, stability, and reactivity of the nanoparticles; 92 refs.

A facile C–H activation and functionalization of aromatic imines is presented using low-valent cobalt catalysts. Using Co(PMe3)4 as catalyst we have developed an efficient and simple protocol for the C–H/hydroarylation of alkynes with an anti selectivity. Deuterium-labeling experiments, DFT calculations coupled with the use of a well-defined catalyst have for the first time shed light on the elusive black box of cobalt catalyzed C–H functionalization.

A copper/phosphoramidite catalyzed asymmetric allylic alkylation of Z trisubstituted allyl bromides with organolithium reagents is reported. The reaction affords all-carbon quaternary stereogenic centers in high yields and very good regio- and enantioselectivity. This systematic study illustrates the crucial role of the olefin geometry of the allyl substrate on the outcome of the reaction and provides a viable alternative to access these important structural motifs.

The radical silylzincation of ynamides (I) and (IX) followed by quenching with NH4Cl and NH3 leads to desired β-silylenamides (III) and (X), resp., with high trans-selectivity.

The novel method using palladium microencapsulated in a polyurea matrix as the catalyst allows the Suzuki—Miyaura coupling of aryl halides with arylboronic acid esters (I) and (IV) in aqueous ethanol.

Optimization of the reaction parameter temperature, solvent, and catalyst loading allows for the development of an improved procedure for the synthesis of title compounds (III).

The title ceramic is prepared by solid state reaction of CaO, Fe2O3, and Fe in a ratio of 1:2:1 (alumina crucible, 1100 °C for 24 h and 900 °C for 48 h).

Five new polyketide derivatives, 6′-hydroxypestalotiopsone C ( 1 ), acropyrone ( 2 ), bicytosporone D ( 3 ), waol acid ( 4 ), and pestalotiopene C ( 5 ), together with seven known metabolites ( 6 – 12 ), were obtained from extracts of the endophytic fungus Acremonium strictum , isolated from the mangrove tree Rhizophora apiculata . The structures of the isolated compounds were elucidated on the basis of comprehensive NMR and MS analysis. Compounds 6 , 7 , and 9 showed moderate cytotoxic activity against human cisplatin-sensitive (IC 50 values 27.1, 76.2, and 8.3 μM, respectively) and resistant A2780 cell lines (IC 50 values 12.6, 30.1, and 19.0 μM, respectively), whereas only 9 exhibited antibacterial activity against Staphylococcus aureus (MIC value 14.3 μM).