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A NaI-promoted sequential double carbon – sulfur bond formation was developed to afford sulfur-bridged imidazopyridines, using Deoxofluor as the sulfur source and requiring only 15 min at room temperature. Using this process, imidazo[1,5-a]pyridines could also be transformed to 1,2,4-thiadiazoles in the presence of ammonium salt with the formation of both carbon – sulfur and nitrogen – sulfur bonds. This mechanistically unique method is distinguished by its wide substrate scope, lack of requirement for transition metals and mild conditions. [ABSTRACT FROM AUTHOR]

Silicon nanowires (Si-NWs) have been fabricated at wafer-scale with Au nanoparticles as catalysts at 500 °C using a chemical-vapor-deposition (CVD) method combined with a high-speed rotation wafer-disk. High resolution TEM and SAED patterns were used to characterize the microstructures of the grown Si-NWs. Single crystalline Si-NWs appear self-oriented on Si (100) substrates along the ＜111＞ growth axis. The nanowires have a uniform diameter of 50 nm and varying lengths and densities depending on the rotation speed of the wafer substrate. The effects of wafer-rotation speed on the growth of Si-NWs are discussed. Due to a reduced boundary layer thickness, fast mass transport leads to both an enhanced growth rate and density of the Si-NWs. Moreover, the density of the Si-NW array is optimized to achieve a low reflectance loss for their further application in tandem solar cells as the light-trapping layer. [ABSTRACT FROM AUTHOR]

A highly diastereo- and enantioselective [3+2] cycloaddition reaction of N-2,2,2-trifluoroethylisatin ketimines and 3-alkenyl-5-arylfuran-2(3H)-ones was developed with 1 mol% thiourea–tertiary amine as the catalyst. A series of spiro[pyrrolidin-3,2′-oxindoles] bearing four consecutive stereocenters, including two vicinal spiro-quaternary chiral centers, were efficiently obtained with excellent results (up to ＞99% yield, ＞20 : 1 dr, and ＞99% ee). [ABSTRACT FROM AUTHOR]

Silicon nanowires (Si-NWs) have been fabricated at wafer-scale with Au nanoparticles as catalysts at 500 °C using a chemical-vapor-deposition (CVD) method combined with a high-speed rotation wafer-disk. High resolution TEM and SAED patterns were used to characterize the microstructures of the grown Si-NWs. Single crystalline Si-NWs appear self-oriented on Si (100) substrates along the ＜111＞ growth axis. The nanowires have a uniform diameter of 50 nm and varying lengths and densities depending on the rotation speed of the wafer substrate. The effects of wafer-rotation speed on the growth of Si-NWs are discussed. Due to a reduced boundary layer thickness, fast mass transport leads to both an enhanced growth rate and density of the Si-NWs. Moreover, the density of the Si-NW array is optimized to achieve a low reflectance loss for their further application in tandem solar cells as the light-trapping layer. [ABSTRACT FROM AUTHOR]

The diastereo- and enantioselective direct vinylogous Michael addition reaction of γ-substituted butenolides to 2-enoylpyridines has been achieved. A range of γ,γ-disubstituted butenolide derivatives, bearing two consecutive tri- and tetrasubstituted stereogenic centers, were readily obtained in good yields with excellent stereoselectivities (up to ＞99 : 1 dr and ＞99% ee). [ABSTRACT FROM AUTHOR]

A novel approach has been developed to prepare the magnetic micelles. Polyethylene glycol (PEG) and poly(N-isopropylacrylamide) (PNIPAM) are firstly attached on the surface of the magnetic nanoparticle via the host–guest inclusion between ferrocene groups (Fc) and β-cyclodextrin (β-CD). Then the resulting MNPs became amphiphilic in water above the LCST of PNIPAM and self-assembled into magnetomicelles with a size of 250 nm. These hybrid micelles show high loading capacity for anticancer drug (DOX) and high saturation magnetization simultaneously. Furthermore, these micelles could disassemble under the effects of oxidant or temperature, providing an opportunity to fine-tune the release properties of the encapsulated drug in response to temperature, H2O2 or pH independently, or a combined effect of multiple stimuli. Taking other advantages of magnetic carriers, such as high sensitivity to the external magnetic field, contrast effect to magnetic resonance, and magnetic hyperthermia, the micelles developed by this study show great potential application in cancer treatment. [ABSTRACT FROM AUTHOR]

A metal-free cross-dehydrogenative coupling of quinones with toluene derivatives has been established. A series of quinones were subjected to reaction with toluene derivatives in the presence of di-tertbutyl peroxide (DTBP) for direct synthesis of benzylquinones. The method exhibits good functional group tolerance, and desired products were obtained in moderate to good yields. Meanwhile, a radical pathway was proposed to describe the cross-dehydrogenative coupling of quinones with toluene derivatives., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

An organocatalyzed direct asymmetric vinylogous Michael addition reaction of α,β-unsaturated γ-butyrolactam to 2-enoylpyridines has been developed with a chiral bifunctional amine-squaramide as the catalyst. This approach provides easy access to a series of optically active α,β-unsaturated γ-substituted butyrolactams in high yields (up to 99%) with excellent diastereoselectivities (up to >99 : 1) and enantioselectivities (up to >99% ee).

A range of 3-pyrrolyl-3,3'-disubstituted oxindoles were smoothly obtained via the reaction of 3-pyrrolyl-oxindoles with nitroalkenes using an organocatalyst. The usefulness of the protocol was also demonstrated by the versatile conversions of the Michael adducts into other functionalized 3,3'-disubstituted oxindoles, as well as into the analogues of some valuable natural products.

A series of novel chiral Lewis base catalysts were synthesized from L-serine and applied in the hydrosilylation of β-enamino esters, in which the optimal one promoted the reactions to afford a wide variety of β-amino esters in good yields with good enantioselectivities. It is noteworthy that several cyclic substrates were hydrosilylated under the optimal conditions to give the cyclic β-amino esters with high yields, good diastereoselectivities as well as good ee values.