Scandium Triflate–Promoted Addition of Organozinc Reagents to Benzaldiminetricarbonylchromium Derivatives

The reaction of benzaldiminetricarbonylchromium derivatives with organozinc reagents in the presence of scandium triflate afforded a single diastereomer of the corresponding amine complex exclusively. Even in the case of benzaldiminetricarbonylchromium having an m‐substituent of the aromatic ring, one diastereomer was obtained using the o‐TMS‐protected chromium complex. The TMS group and the chromium moiety were easily removed and the benzyl group was deprotected using HOOH and Pd to afford the corresponding amine.     

Electron Energy Distribution Function at Potential Drop between two Negative Ar Glow Discharges

The electron energy distribution function was measured at the potential drops (double layer) formed between two negative Ar glows. The acceleration of the electrons by the electric field and the electron trapping due to the high plasma potential formed a double-humped distribution function.     

Development of curved two-dimensional photonic crystal waveguides

A two-dimensional photonic crystal waveguide with a novel geometry is introduced. The center line of this waveguide is bent along a free-curve such that the direction of the propagating light can be changed without scattering or reflection losses. The design method is described for a triangular lattice, its optical properties such as transmission spectrum and dispersion relation are calculated, and actual devices are then fabricated and demonstrated that they worked as optical waveguides.     

Synthesis and chiroptical property of C2-symmetric cyclohexapyrrole

Condensation reaction of gem-dimethyldipyrrylmethane-5,5′-dicarbinol and 4,4′-dimethyl-3,3′-di-iso-butyl-2,2′-bipyrrole under the catalysis by trifluoroacetic acid gave a hexapyrrolic macrocycle 6 in 15% yield after DDQ oxidation. X-ray crystallography of 6 shows that three parts of highly planar dipyrrylmethene unit are assembled by two sp³ hybridized gem-dimethyl carbon bridges and one direct linking at the pyrrole α-positions, leading to C₂ molecular symmetry. The complexation of 6 with (S)-(+)- and (R)-(−)-mandelic acid induced a CD Cotton effect at 461 and 650 nm.     

Sodium arenetellurolate-catalyzed reduction of nitroalkanes to oximes

Treatment of aliphatic nitro compounds with NaBH₄ in alkaline ethanol in the presence of a catalytic amount of diaryl ditelluride at 25°C for 5–20 h produces the corresponding oximes, generally as a mixture of E/Z isomers, in fair to good yields. Arenetellurolate anion (ArTe⁻) generated in situ is suggested to be the active species for the reduction.     

Gallium(III)-catalysed bromocyanation of alkynes: regio- and stereoselective synthesis of β-bromo-α,β-unsaturated nitriles

Treatment of arylacetylenes and cyanogen bromide in ClCH(2)CH(2)Cl with a catalytic amount of GaCl(3) afforded (Z)-β-bromoacrylonitriles with high regio- and stereoselectivity.