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81.
82.
A one-pot synthesis of C1-elongated amides starting from olefins and carbamoyl chlorides has been developed. Alkylboranes, generated by hydroboration of terminal olefins with 9-BBN-H, underwent smooth coupling with carbamoyl chlorides in the presence of palladium catalyst and Cs2CO3. 相似文献
83.
Kamikawa K Takemoto I Takemoto S Matsuzaka H 《The Journal of organic chemistry》2007,72(19):7406-7408
[5]- and [6]helicenes were synthesized in moderate to good yields from Z,Z-bis(bromostilbene)s by palladium-catalyzed double C-H arylation reaction. This method can be applied to the syntheses of helicenes possessing electron-deficient substituents. 相似文献
84.
Inter-Layer Energy Transfer through Wetting-Layer States in Bi-layer InGaAs/GaAs Quantum-Dot Structures with Thick Barriers
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The inter-layer energy transfer in a bi-layer InGaAs/GaAs quantum dot structure with a thick GaAs barrier is studied using temperature-dependent photoluminescence. The abnormal enhancement of the photoluminescence of the QDs in the layer with a larger amount of coverage considering the resonant Forster energy transfer between the at 110K is observed, which can be explained by wetting layer states at elevated temperatures. 相似文献
85.
The oxygen atom of oximes acts as a reactive nucleophile in the iridium-catalyzed allylic substitution of unsymmetrical substrates to give the branched oxime ethers. Among several chiral ligands evaluated, the iridium complex of pybox ligand having phenyl group catalyzed the allylic substitution of phosphates with high activity to form the branched oxime ethers with good enantioselectivities. 相似文献
86.
87.
Takemoto S Ogura S Yo H Hosokoshi Y Kamikawa K Matsuzaka H 《Inorganic chemistry》2006,45(13):4871-4873
A reaction between [CpFeCl]x and LiNHPh (1 equiv to Fe) produces a new paramagnetic Fe(II)-Fe(III) mu2-amido-mu2-imido complex [(CpFe)2(mu2-NHPh)(mu2-NPh)] (1), which, upon interaction with 2,2'-azobis(2,4-dimethylvaleronitrile), undergoes a net N-H hydrogen atom abstraction reaction to give a diamagnetic Fe(III)-Fe(III) mu2-imido dimer [CpFe(mu2-NPh)]2 (2). The molecular structures of 1 and 2 have been determined by single-crystal X-ray diffraction. 相似文献
88.
Acoustic analysis of the vocal tract during vowel production by finite-difference time-domain method
Takemoto H Mokhtari P Kitamura T 《The Journal of the Acoustical Society of America》2010,128(6):3724-3738
The vocal tract shape is three-dimensionally complex. For accurate acoustic analysis, a finite-difference time-domain method was introduced in the present study. By this method, transfer functions of the vocal tract for the five Japanese vowels were calculated from three-dimensionally reconstructed magnetic resonance imaging (MRI) data. The calculated transfer functions were compared with those obtained from acoustic measurements of vocal tract physical models precisely constructed from the same MRI data. Calculated transfer functions agreed well with measured ones up to 10 kHz. Acoustic effects of the piriform fossae, epiglottic valleculae, and inter-dental spaces were also examined. They caused spectral changes by generating dips. The amount of change was significant for the piriform fossae, while it was almost negligible for the other two. The piriform fossae and valleculae generated spectral dips for all the vowels. The dip frequencies of the piriform fossae were almost stable, while those of the valleculae varied among vowels. The inter-dental spaces generated very small spectral dips below 2.5 kHz for the high and middle vowels. In addition, transverse resonances within the oral cavity generated small spectral dips above 4 kHz for the low vowels. 相似文献
89.
Muramatsu W Tanigawa S Takemoto Y Yoshimatsu H Onomura O 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(16):4850-4853
Nonprotected carbohydrates: The catalytic regioselective thiocarbonylation of carbohydrates by using organotin dichloride under mild conditions was demonstrated. The reaction afforded various deoxy saccharides in high yields and excellent regioselectivity in a minimum number of steps. The regioselectivity of the thiocarbonylation is attributed to the intrinsic character of the carbohydrates based on the stereorelationship of their hydroxy groups (see scheme). 相似文献
90.
Tsukano C Okuno M Takemoto Y 《Angewandte Chemie (International ed. in English)》2012,51(11):2763-2766
Quite select: a new strategy was developed for the synthesis of various oxindoles from carbamoyl chlorides. Under the optimum reaction conditions, with Ad(2)PBu as a ligand, tBuCONHOH as an additive, and a CO atmosphere, selective C(sp(3))-H activation proceeded in the presence of a C(sp(2))-H bond. Ad=adamantyl. 相似文献