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71.
Iron‐Catalyzed Dehydration of Aldoximes to Nitriles Requiring Neither Other Reagents Nor Nitrile Media
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Dr. Kengo Hyodo Saki Kitagawa Masayuki Yamazaki Prof. Dr. Kingo Uchida 《化学:亚洲杂志》2016,11(9):1348-1352
The dehydration of aldoximes is an environmentally benign reaction affording the desired nitrile and water as a by‐product. However, most of the reported catalytic dehydration reactions of aldoximes require a solvent containing nitrile to synthesize the corresponding nitrile compounds. Inspired by recent reports on the enzymatic synthesis under nitrile‐free conditions, we here describe that a simple iron salt catalyzes the dehydration of aldoximes requiring neither other reagents nor nitrile media. Our method can be applied to the one‐pot synthesis of nitiriles from aldehydes. 相似文献
72.
Rapid motion capture of phase-controlled wave packets was realized using a sensitive wave-packet spectrometer, which was previously developed by the present authors. Two-dimensional Fourier-transformed spectrograms obtained by the wave-packet spectrometer provide us full information about the wave-packet motion on both excited- and ground-state potential surfaces. Vibrational wave packet associated with a twisting mode in a DTTCI molecule was observed to be dependent on the pulse chirp, and was generated in the excited state preferably with negatively chirped excitation. The result indicates that the excited-state wave packet can be driven along a favorable configuration coordinate by using phase-controlled femtosecond pulses. The present method is essential to adaptive coherent-control application. 相似文献
73.
Stereoselective total synthesis of (+)-Scyphostatin via a pi-facially selective Diels-Alder reaction
Takagi R Miyanaga W Tojo K Tsuyumine S Ohkata K 《The Journal of organic chemistry》2007,72(11):4117-4125
A stereoselective total synthesis of scyphostatin is described. The hydrophilic moiety was stereoselectively synthesized via (i) a highly pi-facially selective Diels-Alder reaction of a spirolactone generated from L-tyrosine and (ii) a hydroxy group directed epoxidation as key reactions. The hydrophilic moiety was combined with the hydrophobic side chain in the final stage. Total synthesis was achieved by overcoming the instability of the C5-C6 epoxide ring with carefully executed mild reactions. In the course of this work, it was revealed that we had mistakenly assigned the relative stereochemistry of the C5-C6 epoxide ring of the end product in our previous model study. Revision of the stereochemical assignment in the model study is described. A diastereomer of (+)-scyphostatin epimeric at C5 and C6 (the epoxide region) was also synthesized. 相似文献
74.
Takahide Y Konoike T Enomoto K Nishimura M Terashima T Uji S Yamamoto HM 《Physical review letters》2007,98(11):116602
We report a large positive magnetoresistance ratio in insulating organic crystals theta-(ET)(2)CsZn(SCN)(4) at low temperatures at which they exhibit highly nonlinear current-voltage characteristics. Despite the nonlinearity, the magnetoresistance ratio is independent of the applied voltage. The magnetoresistance ratio depends little on the magnetic field direction and is described by a simple universal function of mu(B)B/k(B)T, where mu(B) is the Bohr magneton. The positive magnetoresistance may be caused by magnetic-field-induced parallel alignment of spins of mobile and localized electrons, and a resulting blockade of electrical conduction due to the Pauli exclusion principle. 相似文献
75.
Haketa Y Sakamoto S Chigusa K Nakanishi T Maeda H 《The Journal of organic chemistry》2011,76(13):5177-5184
Dipyrrolyldiketone BF(2) complexes acting as acyclic anion receptors form supramolecular assemblies with structures and properties that are dependent on the pyrrole β-substituents. In particular, although β-alkyl substituents interfered with the formation of stable gel states, the introduction of fluorine moieties induced a stable supramolecular gel when compared to that of β-unsubstituted receptor. 相似文献
76.
77.
Fujii Kengo Endo Nobuaki Hagen Nathan Yasugi Masaki Suyama Shiro Yamamoto Hirotsugu 《Optical Review》2022,29(5):429-439
Optical Review - We propose a method to realize video calling with an aerial display using a camera that has a direct view of the speaker's face, but which is not visible to the speaker.... 相似文献
78.
Yoshida K Furuyama T Wang C Muranaka A Hashizume D Yasuike S Uchiyama M 《The Journal of organic chemistry》2012,77(1):729-732
We report synthesis of dibenzoaluminepin as the first aluminepin, an aluminum analogue of borepin and gallepin. This compound contains one molecule of ethereal solvent on the Al atom, which adopts a tetrahedral geometry. The central 7-membered aluminepin ring has a boatlike conformation and was characterized by single-crystal X-ray diffraction, (1)H/(13)C NMR, and DFT studies. In addition, NICS, NBO, and theoretical calculations provide insight into the nature of the bonding and aromaticity of aluminepins. 相似文献
79.
Sumiyoshi T Urabe D Tojo K Sakamoto M Niidome K Tsuboya N Nakajima T Tobe M 《Molecules (Basel, Switzerland)》2012,17(6):6507-6518
We describe in this study the asymmetric synthesis of radioisotope (RI)-labeled selective glucocorticoid receptor modulator. This synthesis is based on optimization of the cinchona alkaloid catalyzed addition of 6-bromoindole to ethyl trifluoropyruvate and Negishi coupling of zinc cyanide to the 6-bromoindole moiety. [1?C] Labeled (-)-{4-[(1-{2-[6-cyano-1-(cyclohexylmethyl)-1H-indol-3-yl]-3,3,3-trifluoro-2-hydroxypropyl}piperidin-4-yl)oxy]-3-methoxyphenyl}acetic acid (-)-1 was synthesized successfully with high enantioselectivity (>99% ee) and sufficient radiochemical purity. 相似文献
80.
We give a modified derivation of the Einstein equation of state by considering the Clausius relation TδS−δN=δQ on a null hypersurface with a non-vanishing expansion (θ≠0), i.e. not in the equilibrium. The derivation corresponds to choosing a specific observer to the hypersurface, and such a generalization gives a hint how we can improve the original derivation by Jacobson. We also give an interpretation of the thermodynamic relation based on the Noether charge method. 相似文献