Highly stereo- and regioselective ni-catalyzed homoallylation of aldimines with conjugated dienes promoted by diethylzinc

Under the nickel catalysis, in one pot, diethylzinc serves as a reducing agent to connect the three components of 1,3-dienes, alkyl or aryl aldehydes, and anilines to furnish 3-substituted 3,5-syn-5-(arylamino)pent-1-enes 1, the homoallylation products of aldimines with dienes, in excellent yields and with high regio- and stereoselectivity.     

Synthesis of 1-hydrocarbon substituted cyclopropyl silyl ketones

The synthesis of cyclopropyl silyl ketones possessing a hydrocarbon group at 1-position of three-membered ring was investigated. The reaction of sulfoxonium ylide with α,β-unsaturated acylsilanes derived from α,β-unsaturated aldehydes did not afford the desired acylsilane derivatives. Instead, the corresponding silyl enol ethers were yielded exclusively. On the other hand, the Corey-Chaykovsky cyclopropanation of α-substituted α,β-unsaturated aldehydes proceeded well to give 1-substituted cyclopropyl aldehydes. The silyl substitution of formyl proton in the obtained aldehydes via umpolung of carbonyl group afforded the target acylsilanes.     

Oxygen island formation on Pt(111) studied by dynamic Monte Carlo simulation

The formation of oxygen islands on the Pt(111) surface has been studied as a function of temperature by low energy electron diffraction (LEED) experiments and dynamic Monte Carlo (DMC) simulations. By raising the temperature, the (2 x 2) LEED spot intensity increases gradually and decays after a peak at around 255 K (T(p)) with full width of half maximum of 160 K. This behavior is interpreted by DMC simulations with the kinematical LEED analysis. In the DMC simulation, an oxygen atom hops to the neighboring site via the activation barrier of the saddle point. The potential energies at initial, saddle, and final points are changed at each hopping event depending on the surrounding oxygen atoms. By comparing the observed T(p) with the simulated one, the interaction energy E of oxygen atoms on Pt(111) was determined to be 25+/-3 meV at 2a(0). The DMC simulations visualize how the oxygen islands are formed and collapse on Pt(111) with increase of the temperature and well reproduce the surface configurations observed by scanning tunneling microscopy.     

Water formation reaction on Pt(111): role of the proton transfer

The catalytic water formation reaction on Pt(111) was investigated by kinetic Monte Carlo simulations, where the interaction energy between reaction species and the high mobility of H(2)O molecule was considered. Results obtained clearly reproduce the scanning tunneling microscopy images which show that the reaction proceeds via traveling the reaction fronts on the O-covered Pt(111) surface by creating H(2)O islands backwards. The reaction front is a mixed layer of OH and H(2)O with a (square root 3 x square root 3)R30(o) structure. Coverage change during the reaction is also reproduced in which the reaction consists of three characteristic processes, as observed by the previous experiments. The simulation also revealed that the proton transfer from H(2)O to OH plays an important role to propagate the water formation.     

Gold-catalyzed intermolecular addition of alcohols toward the allenic bond of 4-vinylidene-2-oxazolidinones

Gold catalyzed intermolecular addition of alcohols toward the proximal allenic double bond of 4-vinylidene-2-oxazolidinones gives hydroalkoxylation products, which can be easily converted into the corresponding novel spiro dihydrofuran or dihydropyran derivatives in high yield.     

Tunable molecular magnetism in conjugated assembly of functional spin units

Molecular design and photoelectrochemically responsive functions of several redox‐tunable building blocks toward conjugated assembling were described. The viologen dimers and pyridylpyridinium dimers through π‐conjugated linkers showed multi‐step redox processes which were demonstrated electrochemically and photochemically. The 4,6‐pyrimidinylene and 3,6‐pyridazinylene linkers played an important role as effective mediators between two attached electrons in the two viologens or pyridinium groups. The latter pyridylpyridinium dimers and 3‐pyridylviologen have potential to coordinate various metal ions to give conjugated self‐assemblies.     

Designing of interference pattern in ultra-short pulse laser processing

We have studied material processing by using an interfering ultra-short pulse laser. In this process, an interference pattern is transferred to material surface, and a periodic structure can be generated in a single shot of laser irradiation. Here, it is well known that the period of the interference pattern can be controlled by correlation angle and wavelength. In addition, a composite, doubled in density or designed interference pattern can be formed by controlling the phase shift and variation of amplitude between the interfering laser beams. In this paper, basic patterns of interference are summarized in the case of four-beam correlation.