Pd- and Cu-catalyzed one-pot multicomponent synthesis of hetero α,α'-dimers of heterocycles

A novel palladium- and copper-catalyzed one-pot multicomponent synthesis of hetero α,α'-dimers of heterocycles via Sonogashira coupling and double cyclization cascade involving imine formation has been developed. This reaction cascade proceeded under mild conditions, providing a powerful synthetic tool for the assembly of π-conjugated systems with a combination of palladium-catalyzed post-direct C-H bond arylations.     

An unexpected disproportional reaction of 2H-azirines giving (1E,3Z)-2-aza-1,3-dienes and aromatic nitriles in the presence of nickel catalysts

An unprecedented nickel-catalysed disproportional reaction of 2,3-diaryl-2H-azirines forming azabutadienes and aromatic nitriles was discovered. This reaction involves the cleavage of two bonds of the 2H-azirine framework, which provides a novel type of transformation of 2H-azirines.     

Practical synthesis of aromatic nitriles via gallium-catalysed electrophilic cyanation of aromatic C-H bonds

A gallium-catalysed, direct cyanation reaction of aromatic and heteroaromatic C-H bonds with cyanogen bromide was developed as a practical synthetic method for the preparation of aromatic nitriles.     

Fast and highly accurate boundary element method for scattering calculation of defective gratings

A numerical scattering calculation method for defective gratings is proposed. This method is based on an integral equation method that computes a difference-field distribution, which is the difference between the scattering fields with and without the defect, and it is possible to simulate the arbitrary (finite) size and shape of a defect in the grating without any limitation. A calculation example is also presented to demonstrate the fast convergence and high accuracy of this method.     

Time-domain observation of the spinmotive force in permalloy nanowires

The spinmotive force associated with a moving domain wall is observed directly in Permalloy nanowires using real time voltage measurements with proper subtraction of the electromotive force. Whereas the wall velocity exhibits nonlinear dependence on magnetic field, the generated voltage increases linearly with the field. We show that the sign of the voltage reverses when the wall propagation direction is altered. Numerical simulations explain quantitatively these features of spinmotive force and indicate that it scales with the field even in a field range where the wall motion is no longer associated with periodic angular rotation of the wall magnetization.     

Stereoselective allylation of azirines with allylindium reagents

Allylindium reagents allylated azirines to give allylaziridines in good yields. The delivery of the allyl group was well regulated by the substituents at the C³-carbon of azirines. The cis-allylation with respect to the substituent was realized with azirines bearing a hydroxylmethyl or an acetoxymethyl group due to the chelation with allylindium reagents, whereas the trans-allylation was achieved with azirines substituted by a methyl, phenyl, or ester group owing to the steric repulsion.     

Allylgallation of cyclopropenes. Crystal structure of a novel cyclopropylgallium compound prepared by allylgallation of hydroxy-bearing cyclopropene

Allylgallation of cyclopropenes with allylgallium sesquibromide has been investigated; a novel cyclopropylgallium compound was isolated via allylgallation of hydroxy-bearing cyclopropene, and its structure was fully characterized by X-ray crystallography.     

Stereoselective Construction of 1,3‐Disilylcyclopentane Derivatives by Scandium‐Catalyzed [3+2] Cycloaddition of Allylsilanes to β‐Silylenones

The Sc(OTf)₃‐catalyzed [3+2] cycloaddition of allylsilanes to β‐silyl‐α,β‐unsaturated ketones (β‐silylenones) has been developed to form five‐membered syn‐1,3‐disilylketones diastereoselectively through the rearrangement of the silicon substituents on the allylsilane. Stabilization of the carbocation intermediates by a double silicon effect plays a key role in directing the course of the reaction to favor the [3+2] cycloaddition pathway over simple allylation.