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A novel copper-catalyzed difluoromethylation of 2- or 3-propargylamide-substituted indoles with ICF2CO2Et via a radical cascade cyclization process is described. A wide substrate scope is compatible with the reaction conditions to synthesize mono- and bis-difluoromethylated indoloazepinone derivatives, which contain a seven-membered ring.

A novel, four-component synthetic strategy to synthesize a series of β-difluoroalkyl unsaturated esters/amides with high regioslectivity is described. This Pd-catalyzed difluoroalkylation and carbonylation reaction can be carried out with simple starting materials. Through this protocol, two new C–C bonds (including one C–CF2 bond) and one C–O(N) bond are constructed simultaneously in a single step. The synthetic utility of this reaction system has been certified by the applicability to a wide scope of alkynes and nucleophiles. Preliminary mechanistic studies suggest that the difluoroalkyl radical pathway is involved in this reaction.

A method for the synthesis of trifluoromethyl CF3-substituted spirocyclic compounds containing with a unique quaternary carbon center from readily available starting materials has been developed. The reaction provides a facile access to 2H-azirines via cascade cyclization. These compounds constitute a new class of functionalized synthetic intermediates, which can be used for the synthesis of various nitrogen-containing heterocycles and biologically active CF3-containing compounds.

The title compound (dap: 1,2-diaminopropane) is synthesized by hydrothermal reaction of Na10[A-α-SiW9O34], CuCl2, YCl3, dap, and HCl in aqueous solution (autoclave, 160 °C, 5 d, 24% yield).

The simple procedure works successful in the condensation of aromatic and α,β-unsaturated aldehydes.

The regio- and stereoselective synthesis of peracetylated carbohydrate esters of stearic acid of type (VI)/(VII) or (IX)/(X) using p-toluenesulfonic acid as catalyst is described.

The Michael addition reactions of β-nitrostyrenes 1 with 4-pentene-1-magnesium bromide 2a or 3-butene-1-magnesium bromide 2b generated nitronates 3 or 4. Medium to high yields of isoxazolidine derivatives 9 and 10 were obtained when nitronates 3 or 4 were treated with ethyl chloroformate and catalytic amount of 4-dimethylaminopyridine (DMAP) at room temperature in one-pot and the ratios of trans-9: cis-9 were from 1:3.00 to 1:4.06 and the ratios of trans-10:cis-10 were >99:1. The formation of compounds 9 is proposed to proceed through intramolecular nitrile oxide-olefin cycloadditions (INOC) because compounds 14a-d, obtained from the trapping of the nitrile oxides by ethyl chloroformate, could be isolated. The mechanism of the generation of compounds 10 is proposed to proceed through intramolecular alkoxycarbonyl nitronate-olefin cycloadditions (IAOC) to form intermediates N-(ethoxycarbonyl)isoxazolidines 13 and then eliminate EtOH and CO2 (or EtOCO2H) to yield the final products.

The Michael addition of the diethyl allyl malonate anion to β-nitrostyrenes 1 generated nitronates 5. Nitronates 5 could be converted into nitrile oxides 7 to undergo intramolecular nitrile oxide–olefin cycloaddition (INOC) to form medium to high yields (51–95%) of five-membered carbocycles 8 and 9 by using ethyl chloroformate in the presence of a catalytic amount of 4-dimethylaminopyridine (DMAP). High yields (91%) of tricyclic compounds 11 and 12 were obtained when 1a reacted with the anion of 10 under similar experimental conditions and procedures.

Reaction of β-nitrostyrenes 1 with allyl mercaptan 2 in the presence of triethylamine generated unsaturated nitro sulfides 3 and then the solution was treated with methyl chloroformate (MCF) and was refluxed to obtain [3.3.0]bicyclic products trans-6 and cis-6 in one-pot. The rations of trans-6:cis-6 were from 1.1:1 to 1.8:1 and the mechanism of the formation 6 is proposed to proceed through the formation of nitrile oxides 5 to undergo intramolecular nitrile oxide-olefin cycloaddition (INOC). Nitronates 16, prepared from 1 with allyl alcohol and base, can be converted into methoxycarbonyl nitronates 22 by treating the solution with methyl chloroformate and calytic amount of 4-dimethylaminopyridine (DMAP) in the presence of different amounts of triethylamine. Intermediates 22 can either undergo intramolecular alkoxycarbonyl nitronate-olefin cycloaddition (IAOC) to generate highly stereoselective product trans-14 or undergo INOC to yield trans-14 and cis-14. The application of this improved methodology to synthesize different heterocyclic products 10, 26, and 27 is reported.

Methyl- and phenyl-substituted N-(ethoxycarbonyl)-2-azabicyclo[2.2.0]hex-5-enes 6 were reacted with NBS in wet DMSO to afford bromohydrins. Mixtures of unrearranged 6-exo-bromo-5-endo-hydroxy-2-azabicyclo[2.2.0]hexanes 7a,b and rearranged 5-anti-bromo-6-anti-hydroxy-2-azabicyclo[2.1.1]hexanes 8a,b were formed stereoselectively from the parent alkene 6a and 4-methyl alkene 6b. The 5-methyl alkene 6c affords only unrearranged bromohydrin 7c and dibromohydrin 9. By contrast, solely rearranged 3-endo-substituted-2-azabicyclo[2.1.1]hexane bromohydrins 8d-f result from additions to 3-endo-methyl alkene 6d, 3-endo-4-dimethyl alkene 6e, and 3-endo-phenyl alkene 6f. As an alternative route to bromohydrins, the parent 5,6-exo-epoxide 10a and 5-endo-methyl-5,6-exo-epoxide 10b were ring opened with bromine/triphenylphosphine to afford unrearranged 5-endo-bromo-6-exo-hydroxy-2-azabicyclo[2.2.0]hexanes 11a,b, while the 3-endo-methyl epoxide 10c afforded solely the rearranged 5-anti-bromo-6-anti-hydroxy-3-exo-methyl-2-azabicyclo[2.1.1]hexane isomer 8g. Tributyltin hydride reduction of bromohydrins 7a,b and 11a afforded novel 2-azabicyclo[2.2.0]hexan-5-ols 13a,b and -6-ol 14, and bromohydrins 8a,b, 8d-g afforded new 2-azabicyclo[2.1.1]-hexan-5-ols 15a,b and 15d-g.

The Sonogashira cross-coupling of aryl iodides with terminal alkynes catalyzed by a simple and inexpensive catalyst system of CuI/PPh3 in water as the sole solvent has been reported. In the presence of CuI/PPh3, with KOH used as a base, a number of aryl iodides were treated with alkynes to afford the corresponding products in moderate to excellent yields. Copyright © 2008 John Wiley & Sons, Ltd.

Rodlike and cubiform hematite nanocrystals free of organic contaminants were controllably synthesized via hydrothermal processing of an air-stable metallorganic molecular precursor (ferric acetylacetonate: Fe-(ACAC) 3 ) in distilled water, simply by adjusting the reaction temperatures (140–180 °C) and reaction times (1.5–12 h); while pure quadrate maghemite nanocrystals were obtained by direct thermolysis of the Fe-(ACAC) 3 in air at 300 °C for 3 h. The phase, morphology, size, and purity of the as-prepared products were characterized by powder X-ray diffraction, transmission electronic microscope, Fourier transform infrared spectroscopy and Raman spectroscopy. The magnetization measurements revealed that the as-prepared hematite nanocrystals all showed a typical superparamagnetic behavior at room temperature, except some variation in the values of remanences and coercive forces with different product morphologies; while the as-prepared maghemite nanocrystals showed a ferromagnetic behavior at room temperature.

Stereoselective styryl derivatives have been prepared based on radical substitution (addition-elimination) of heterocycles or cyclohydrocarbons units to (E)-beta-nitrostyrenes 1 using a common radical initiator benzoyl peroxide. High reactivity and selectivity with wide substrate scope were attained by using this easy methodology. The reactions using easily obtained and one-pot potential starting materials gave excellent trans-selectivity with medium to high yields in all cases. Synthetic utility of this approach has been demonstrated by the preparation of various trans-styryl derivatives.