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The synthesis of 1,2′-biazulenes was established by palladium-catalyzed homocoupling reactions of the corresponding 1-haloazulenes in the presence of ferrocene. The optical properties of the novel 1,2′-biazulenes were investigated by UV/Vis spectroscopy and theoretical calculations. The redox behaviors of 1,2′-biazulenes were also examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV).

Prismatic single crystals of novel compounds BaLaSi2 and Ba5LaSi6 were synthesized from the elements with or without a Na flux. The crystal structures of the compounds were analyzed by X-ray diffraction. BaLaSi2, containing cis–trans ∞1[Si] chains, crystallizes in an orthorhombic cell (a = 4.6414(2) A, b = 14.8851(7) A, c = 6.7519(5) A; space group, Cmcm (No. 63), Z = 4) and is isotypic with the low-temperature phase of LaSi. The crystal structure of Ba5LaSi6 (a = 17.1447(5) A, b = 4.8767(1) A, and c = 17.9102(4) A; space group Pnma (No. 62), Z = 4) is a new type containing isolated anionic groups (0[Si5–Si]) of a pentagonal Si ring with a Si–Si stem. The electrical resistivities measured for the polycrystalline BaLaSi2 and Ba5LaSi6 sintered samples were 0.31 and 0.48 mΩ·cm, respectively, at 300 K and increased with temperature. The Seebeck coefficients of BaLaSi2 and Ba5LaSi6 were −7.6 and −11 μV·K–1, respectively, at 296 K.

The esterification of the sterically hindered 5-OH group of p-methoxybenzyl quinate (I) obtained in five steps from commercially available (-)-quinic acid is presented.

Novel main group element compounds, geminal dianionic derivatives of the heavier group 14 elements; namely, 1,1-dilithiosilanes, 1,1-dilithiogermanes and 1,1-dilithiostannanes (and closely related derivatives of the cyclopentadiene-1,1-diide and cyclobutadiene dianion), are the focus of the present review. The synthetic strategies for their preparation, structural features, and synthetic applications are discussed.

AlCl3-mediated reaction of 2-hydroxyazulenes with β-ketoesters provides the title species in low to moderate yields.

The reaction of N-aryl benzamidines 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l, 1m, 1n with diphenyl carbonate 2a or ethyl phenyl carbonate 2b synthesized 2-arylquinazolin-4(3H)-ones 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l, 3m, 3n in simple and safe process with good yields (71–90%). It was suggested that different electron-donating substituent in N-aryl benzamidines 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l, 1m, 1n afforded similar effect to the yields of 2-arylquinazolin-4(3H)-ones 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l, 3m, 3n. In these reactions, N-aryl benzamidines 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l, 1m, 1n built up intermediate compounds by nucleophilic addition to carbonates 2 to give annulation products 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l, 3m, 3n, following to cyclization involving the elimination of ethanol/phenol.

The title reaction proceeds without a metal catalyst by a unique mechanism involving SET oxidation by means of aryliodonium salts followed by electron-rich aryl transfer.

Reaction of tetrakis(trimethylsilyl)tetrahedrane with MeLi produces a solution of tris(trimethylsilyl)tetrahydryl lithium which is easily amenable for Pd-catalyzed cross-coupling processes to produce thermally stable arylated tetrahedranes.

A modified synthesis of 2-mercaptooxazoles (III) via an iminophosphorane-mediated reaction and its application to the multi-gram preparation of compound (IIIi), a key intermediate for PI3Kγ inhibitors, is reported.

The blue-emitting title phosphors are synthesized from mixtures of AlN, α-Si3N4, SrCO3, and Eu2O3 (1 MPa N2, 1800 °C, 2 h).

The presented approach can be combined with known Negishi cross-coupling for the expeditious access to multiple arylated thiophenes.

Unsaturated main group 14 species have unique properties and reactivity compared with their organic analogues. The isolation of stable disilynes, one of the most recent and intriguing additions to ...

The synthesis of the novel silylated digermene (II) is achieved via reduction of the dichlorine precursor (I) with potassium graphite.

Two novel alkaloids with a furo[2,3-b]pyrazin-2(1H)-one moiety and a guanidino group, hyrtioseragamines A (1) and B (2), have been isolated from an Okinawan marine sponge Hyrtios species. The structures of 1 and 2 were elucidated on the basis of spectroscopic data and chemical conversions. Compounds 1 and 2 are the first natural products possessing a furo[2,3-b]pyrazine-related moiety.

A C–N bond of spermine coordinated to cobalt(III) is cleaved through site-selective oxidation to yield 1,5-diazabicyclo[4.3.0]nonane and complexes containing 1,3-diaminopropane in an aqueous solution.

New selenium-containing heterocyclic compounds, 6H-1,3,5-oxaselenazines, have been synthesized stereoselectively by the reaction of selenoamides with aldehydes in the presence of boron trifluoride etherate complex.

The reduction of elemental selenium by samarium diiodide led to selective formation of selenolate anion species (Se2− and Se22−), the alkylation of which provided dialkyl selenides and diselenides, respectively, in excellent yields.

Separated were 1,1,1-trifluoro-4-mercapto-4-(2-thienyl)-3-butene-2-one (thiothenoyltrifluoroacetone, STTA) chelates of Zn2+, Cu2+, Cd2+, Ni2+, Co3+ by reversed phase high performance liquid chromatography (RP-HPLC). The elution of the STTA chelates of Cd2+, Zn2+, and Ni2+ was delayed by the addition of pyridine, α-picoline, or γ-picoline, indicating the formation of the adducts.

Diphenyl diselenide promotes the radical addition of benzeneselenol to inactivated acetylenes upon irradiation through Pyrex with a tungsten lamp. The addition may proceed by a radical chain mechanism that involves phenylseleno radical (PhSe·) as the key species, generated by the photolysis of (PhSe)2.

N,N-Disubstituted selenoamides were found to undergo deselenative coupling by the action of copper(0), providing 1,2-enediamines in good yields. The driving force of this reaction may be a high affinity of selenium for soft metals such as copper.

The oxidation of 1,2-bis(phenylseleno)-1-alkenes and the reactivity of thus formed selenoxides have been investigated. When (Z)-1,2-bis(phenylseleno)-1-octene was oxidized with two equivalents of MCPBA, a novel selenoxide anti-elimination has been found to take place at or below room temperature.

Recent works on ethylene dianions and benzene dianions are reviewed. Silyl substituted dianions, [Li (thf)] 2 [(Me3Si) 2C=C (SiMe3) 2], [Li (thf)] 2 [(HMe2Si) 2C=C (SiMe2H) 2], [Li (dme)] 2 [(Me3Si) 2C=C (SiMe3) Ph], [Li2 (thf) 3] [Me3Si) 2C = CPh2], [Li (thf)] 2 [(Me3Si) 6C6], and [Li (dme)] 2 [1, 2, 4, 5- (Me3Si) 4C6H2], are reported. X-ray crystallographic analyses of these dilithium complexes revealed interesting features on the molecular structures. Silyl substituted cyclopentadienyllithium, [Li (C7H13N)] [(HMe2Si) 5C5], is also described.

Condensations of R(Ph)GeCl2 (R = t-Bu and R = CEt2Me) with Mg/MgBr2 in THF produced cyclotetragermanes [R(Ph)Ge]4, which were converted to [R(Cl)Ge]4 by treatment with HCl/AlCl3 or with CF3SO3H followed by CH3COCl. The crystal structure of [t-Bu(Cl)Ge]4 was established by X-ray diffraction. Unusual configurational behavior of cyclotetragermanes is also described.

Herein we report the novel finding that a samarium/samarium diiodide mixed reagent (Sm/SmI{sub 2}) successfully effects the deoxygenative coupling of amides, which provides a powerful tool for preparing vic-diaminoalkenes. However, a reaction system combining SmI{sub 2} with samarium metal accomplished deoxygenative coupling to provide vic-diaminoalkenes in excellent yields. As can be seen in the experiments varying the molar ratio of Sm/SmI{sub 2}, the yield of coupling product 2a was dependent on the amount of samarium metal (runs 1-3). More remarkable is the observation that magnesium metal (Mg{sup 2+}/Mg = -2.37 V), which has a reducing power similar to that of samarium metal (Sm{sup 3+}/Sm = -2.41 V), also effected the coupling of 1a in the presence of SmI{sub 2} (run 6). 17 refs., 2 tabs.

Arabinoaminooxazoline reacted readily with α-(bromomethyl)acrylate derivatives to afford the corresponding adduct. Potassium tert-butoxide- or sodium methoxide-catalyzed cyclization of the adduct gave 5-substituted 2,2′-anhydroarabinofuranosyluracil derivatives.

5-Substituted uracil nucleosides useful for the attachment of linker arms to nucleic acids are prepared from arabinoaminooxazoline and dimethyl α-bromomethylfumarate in a short reaction sequence without using any protecting groups, and incorporated into oligodeoxyribonucleotides.

The fluoro-dediazoniation of ArN2BF4 using HF-pyridine solution has been successfully carried out either thermally or photochemically to afford the corresponding ArF in good yields. Particularly, t...

The electrochemical oxidation of 2,2-disubstituted cyclic ketones was carried out using Et3N-5HF as the electrolyte. The selective cleavage of the carbon-carbon bond between the carbonyl carbon and substituted α-carbon took place and fluorocarboxylic acid esters (2) were obtained in good yields after the esterification of the resulting fluoroacyl fluorides (1).

A number of compounds with heteronuclear double bonds between heavy elements of groups 13, 14, 15, and 16 have been isolated and characterized in the last three decades; they are kinetically stabilized by the use of bulky substituents or thermodynamically stabilized by intra- or intermolecular coordination. They are fascinating compounds in respect of their unusual chemical properties, being very useful building blocks in organometallic chemistry.

β-Ketoesters are selectively fluorinated at the α-position by iodotoluene difluoride and a HF–pyridine complex.