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Jun Terao

Publications and source records attributed to Jun Terao.

12 recordsLinked to original sources

Self-organized interconnect method for molecular devices.

Lack of an appropriate method for wiring molecules that have controlled functions and structures has been a barrier for the development of molecular devices. We developed an interconnect method to program three kinds of component molecules with their own functions and to wire a molecular device in a self-organized manner. By using the interconnect method we developed, we produced conductive wires and optical switching devices and have demonstrated their device functions. Our interconnect method allows us to control various molecular device characteristics by combining the three molecules.

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cis-to-trans isomerization promoted by pyridine as a crucial step for the selective preparation of trans-Pt(SAr)(Cl)(PAr'3)2.

The general strategy for the syntheses of trans-Pt(SAr)(Cl)(PAr'3)2 (1) (Ar = Ph, C6H4-2-Me, C6H4-3-OMe C6H4-2-F, etc.; Ar' = Ph, C6H4-4-OMe, C6H4-4-Me, and C6H4-4-CF3) by the reaction of cis-PtCl2(PAr'3)2 with ArSH has been developed. The mechanistic investigation suggested that isomerization of cis-1 into trans-1 promoted by the combined use of C6H6 as a solvent and pyridine as a base was the key to the successful preparation of 1.

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Ni-catalyzed alkylative dimerization of vinyl grignard reagents using alkyl fluorides.

Alkyl halides underwent unique cross-coupling reaction with vinylmagnesium chloride in the presence of Ni catalyst to give 2-alkyl-3-butenyl Grignard reagent (1) in high yields. This reaction proceeded efficiently at 25 degrees C in THF using primary and secondary alkyl fluorides. On the other hand, PhCH=CHMgBr gave double alkylative vinyl coupling product 4 in good yield as the sole coupling product. Alkyl fluorides react as the most suitable alkylating reagent in comparison to the corresponding chlorides, bromides, and iodides.

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Palladium-catalyzed dimerization disilylation of 1,3-butadiene with chlorosilanes.

[reaction: see text] 1,3-Butadiene reacted with chlorosilanes and Grignard reagents at 20 degrees C in the presence of a catalytic amount of Pd(acac)(2) to give disilylated dimers 2 regioselectively, which have two silyl groups (R(3)Si) at the 3- and 8-positions of a 1,6-octadiene skeleton. When phenyl- or allyl-substituted chlorosilanes were used, coupling product was obtained stereo- as well as regioselectively, giving rise to only (E)-olefins. It is proposed that Pd-ate complexes play important roles in both C-Si bond-forming processes.

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Titanocene-catalyzed regioselective carbomagnesation of alkenes and dienes.

A new method for regioselective carbomagnesation of alkenes and dienes has been developed by the use of a titanocene catalyst. This reaction proceeds efficiently at 0 degrees C in THF in the presence of Cp(2)TiCl(2) by the combined use of organic halides (R-X; R = alkyl, aryl and vinyl) and n-BuMgCl to afford benzyl, alpha-silylalkyl, or allyl Grignard reagents, which were trapped with various electrophiles. The present reaction involves (i) addition of carbon radicals toward alkenes or dienes in the carbon-carbon bond-forming step and (ii) transmetalation on Ti of benzyl-, alpha-silylalkyl-, or allyltitanocene with n-BuMgCl in the carbon-magnesium bond-forming step. The scope and limitations of this reaction have also been examined.

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Ni- or Cu-catalyzed cross-coupling reaction of alkyl fluorides with Grignard reagents.

n-Octyl fluoride underwent a cross-coupling reaction with n-propylmagnesium bromide in the presence of 1,3-butadiene using NiCl2 as a catalyst at room temperature to give undecane in moderate yields. This alkyl-alkyl cross-coupling proceeded more efficiently when CuCl2 was employed instead of NiCl2. Addition of 1,3-butadiene dramatically improved the yields of the coupling products from primary alkyl Grignard reagents in both Ni- and Cu-catalyzed reactions. Alkyl fluorides efficiently reacted with tertiary alkyl and phenyl Grignard reagents using CuCl2 in the absence of 1,3-butadiene to afford the coupling products in high yields. The competitive reaction of a mixture of alkyl halides (R-X; X = F, Cl, Br) with nC5H11MgBr showed that the reactivities of the halides increase in the order R-Cl < R-F < R-Br. In contrast, in the Cu-catalyzed reaction with PhMgBr, the reactivities increase in the order R-Cl < R-Br < R-F.

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Nickel-catalyzed cross-coupling reaction of grignard reagents with alkyl halides and tosylates: remarkable effect of 1,3-butadienes.

A new method for the cross-coupling reaction of Grignard reagents with alkyl chlorides, bromides, and tosylates has been developed by the use of a nickel catalyst in the presence of a diene as an additive. This reaction proceeds efficiently at 0-25 degrees C in THF using primary and secondary alkyl and aryl Grignard reagents. Nickel complexes bearing no phosphine ligands, such as NiCl2, Ni(acac)2, and Ni(COD)2, afford the coupling products in good yields, whereas NiCl2(PPh3)2 and NiCl2(dppp) were less effective. 1,3-Butadiene shows the highest activity as an additive for the present coupling reaction. A plausible reaction pathway was proposed.

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