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41.
Ochiai M Takeuchi Y Katayama T Sueda T Miyamoto K 《Journal of the American Chemical Society》2005,127(35):12244-12245
Reported here for the first time is the iodobenzene-catalyzed alpha-oxidation of ketones, in which diacyloxy(phenyl)-lambda3-iodanes generated in situ act as real oxidants of ketones and m-chloroperbenzoic acid serves as a terminal oxidant. Oxidation of a ketone with m-chloroperbenzoic acid in acetic acid in the presence of a catalytic amount of iodobenzene, BF3.Et2O, and water at room temperature under argon affords an alpha-acetoxy ketone in good yield. p-Methyl- and p-chloroiodobenzene also serve as efficient catalysts in this direct oxidation. We found that when the reaction was carried out in the absence of a catalytic amount of iodobenzene, Baeyer-Villiger oxidation of a ketone took place. It is noted that use of water and BF3.Et2O is crucial to the success of this alpha-acetoxylation. 相似文献
42.
Exposure of 1-alkynyl[p-(trifluoromethyl)phenyl](tetrafluoroborato)-lambda3-bromanes to 2-mercaptobenzimidazole or benzothiazole in dichloromethane at 0 degrees C under argon resulted in a domino Michael addition-carbene rearrangement-cyclization reaction to produce directly tricyclic heterocycles in high yields, whereas the reaction with 2-mercaptobenzoxazole afforded 1-alkynyl sulfides. 相似文献
43.
Thermal decomposition of 1-tert-butylperoxy-1,2-benziodoxol-3(1H)-one in cyclic ethers and acetals at 50 degrees C generates alpha-oxy carbon-centered radicals, which undergo an addition reaction with vinyl sulfones and unsaturated esters. 相似文献
44.
K. Hayashi K. Hotai M. Hayakawa Y. Ochiai H. Matsuda S. Uedaira K. Aso 《Journal of magnetism and magnetic materials》1983,38(2):142-146
The effects of the substitutions of 3d-, 4d- and 5d-transition metals for silicon on magnetostriction of Co-based amorphous alloys have been investigated by measuring the tension dependence of anisotropy field in magnetic hysteresis loop. Fractional changes of the magnetostriction with transition metal solutes in Co-based amorphous alloys are qualitatively discussed in terms of the magnetic moment and coordination number, and classified into 3 types, i.e., positive, negative and complicated types, from a viewpoint of the contribution to magnetostriction. 相似文献
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Morimoto T Henmi M Naito R Tsubaki K Aoki N Bird JP Ochiai Y 《Physical review letters》2006,97(9):096801
We report on a remarkable resonance in the differential conductance of long quantum point contacts (QPCs) that is observed as a precursor to regular quantized transport. This effect is increasingly pronounced in longer QPCs, in which the differential conductance may resonantly exceed 2e2/h. From a study of the experimental characteristics of this feature, we suggest that it may be associated with the formation of a well-resolved energy gap that opens dynamically as a result of enhanced many-body interactions in long QPCs. 相似文献
47.
Yoshitake Yamazaki Arno Holz Herbert Gleiter Yoshiichi Fukuda Moyuru Ochiai 《Phase Transitions》2013,86(1-4):109-144
We shall focus on extended defect systems and review their critical behavior. Primarily, with two aims, one of which is to understand phase transitions and how to derive effective dimension of extended defects with various structures, and the other is to propose a new research-method for defect systems, we let extended defects grow on a triangular lattice with frustration in a similar fashion to diffusion-limited aggregation, and discuss the situation. The existence of phase transitions, phase diagram, effective defect dimension, etc. will be shown. Furthermore, we shall summarize theoretical studies of extended defect systems on phase diagrams, critical behavior, tricritical behavior, and crossover behavior as static properties, and on nonconserved systems and conserved systems as dynamic properties. 相似文献
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Tatsumi Ochiai Dr. Daniel Franz Dr. Elisabeth Irran Prof. Dr. Shigeyoshi Inoue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(18):6704-6707
The novel amino(imino)stannylene 1 was prepared by conversion of HNIPr (NIPr=bis(2,6‐diisopropylphenyl)imidazolin‐2‐imino) with one equivalent of Lappert’s tin reagent (Sn[N(SiMe3)2]2). Treatment of 1 with DMAP (4‐dimethylaminopyridine) yields its Lewis acid–base adduct 2 . The reaction of 1 with one equivalent of trimethylsilyl azide results in replacement of the amino group at the tin center by an N3 substituent with concomitant elimination of N(SiMe3)3 to afford dimeric [N3SnNIPr]2 ( 3 ). Remarkably, the reaction of 1 with B(C6F5)3 produces the novel tin(II) monocation 4 +[MeB(C6F5)3]? comprising a four‐membered stannacycle through methyl‐abstraction from the trimethylsilyl group. 相似文献