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121.
Koichi Mitsudo 《Tetrahedron letters》2008,49(46):6593-6595
An electrochemical method for generating cationic palladium complexes was integrated into an electrooxidative homo-coupling of arylboronic acids. In the presence of a catalytic amount of TEMPO, the homo-coupling reaction proceeded efficiently under argon to afford symmetric biaryls. 相似文献
122.
Prof. Dr. Shintaro Ishida Takuroh Hatakeyama Takuya Nomura Maiko Matsumoto Dr. Kimio Yoshimura Prof. Dr. Soichiro Kyushin Prof. Dr. Takeaki Iwamoto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):15811-15815
The catalyst-free hydrosilylation of CO2 under mild conditions remains limited. Herein, we report the synthesis, characterization, and reactivity of 5,10,15,20-tetraphenylporphyrinato(dihydrido)silicon(IV) ( 1 ) as a six-coordinate silicon dihydride. The Si-H moiety of 1 reacts with polar double bonds and CO2 in the absence of a catalyst to afford hydrosilylated products. Combining the hydrosilylation with subsequent transformation furnishes formic acid from CO2. Computational studies indicate that the hydride-donor properties of 1 are exceptionally high for a neutral silicon hydride, and that the direct hydride transfer from silicon to carbon is a pivotal step in the hydrosilylation of CO2 with 1 . 相似文献
123.
An Operator Transform from Class A to the Class of Hyponormal Operators and its Application 总被引:1,自引:0,他引:1
In this paper, we shall give an operator transform
from class A to the class of hyponormal operators. Then we shall show that
and
in case T belongs to class A. Next, as an application of
we will show that every class A operator has SVEP and property (β). 相似文献
124.
Sufficient conditions are given that certain statistics have a common distribution under a wide class of underlying distributions. Invariance methods are the primary technical tool in establishing the theoretical results. These results are applied to MANOVA problems, problems involving canonical correlations, and certain statistics associated with the complex normal distribution. 相似文献
125.
126.
127.
Novel intermolecular carbon radical addition to a nitrone: asymmetric synthesis of alpha-amino acids
Ueda M Miyabe H Teramachi M Miyata O Naito T 《Chemical communications (Cambridge, England)》2003,(3):426-427
A nitrone was used as a synthetically useful radical acceptor in carbon-carbon bond-forming radical reactions; the intermolecular addition of alkyl radicals to chiral glyoxylic nitrone was studied; a high degree of stereocontrol in radical addition to glyoxylic nitrone was achieved to provide a new method for asymmetric synthesis of alpha-amino acids. 相似文献
128.
129.
We propose a polynomial-time-delay polynomial-space algorithm to enumerate all efficient extreme solutions of a multi-criteria minimum-cost spanning tree problem, while only the bi-criteria case was studied in the literature. The algorithm is based on the reverse search framework due to Avis and Fukuda. We also show that the same technique can be applied to the multi-criteria version of the minimum-cost basis problem in a (possibly degenerated) submodular system. As an ultimate generalization, we propose an algorithm to enumerate all efficient extreme solutions of a multi-criteria linear program. When the given linear program has no degeneracy, the algorithm runs in polynomial-time delay and polynomial space. To best of our knowledge, they are the first polynomial-time delay and polynomial-space algorithms for the problems. 相似文献
130.
Nakakoshi M Ueda M Sakurai S Miyata O Sugiura M Naito T 《Magnetic resonance in chemistry : MRC》2006,44(8):807-812
The structures of the components in the triethylborane-mediated radical addition reaction of oxime ether were investigated by 1H- and 3D-DOSY NMR methods. It has been impossible to physically separate the unstable intermediates; therefore, the structures were thus far unidentified. It has been possible to elucidate the structures of these unstable intermediates using Diffusion-Ordered Spectroscopy (DOSY) methods for the reaction in an NMR tube. The DOSY methods resolved the spectra of each starting compound, intermediate and product having different diffusion coefficients. The structure of the intermediate was shown to be due to the bonding of diethylborane to the nitrogen atom of the alkoxyamino group. 相似文献