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Your search keyword '"Yoshito Tobe"' showing total 21 results
Start Over Author "Yoshito Tobe" Publisher american chemical society
21 results on '"Yoshito Tobe"'

1. Unusual reactivity of (6)paracyclophane toward alkyllithiums

Author

Yoshito Tobe, Mamoru Jimbo, Shinji Saiki, Kiyomi Kakiuchi, and Koichiro Naemura

Subjects
Organometallic compounds -- Analysis, Organic compounds -- Analysis, Reactivity (Chemistry) -- Analysis, Biological sciences, Chemistry
Abstract

Increased sensitivity is seen in strained (n)cyclophanes, which are subjected to rare interactions in electrophilic interactions. The aromatic ring undergoes a strain which is characterized by incorporation and reorganization interactions. The early stage of the interactions omit these strains in substantial quantities. Transition-state energy is reduced by enhanced HOMO levels. Nucleophilic interactions with increased reactivity are exhibited by strained cyclophanes due to strain emissions. LUMO level nucleophilic replacement is seen in 8,11-dihalo-substituted (5)metacyclophanes, which are the tiniest isolable (n)metacyclophane products. Powerful classes which withdraw electrons do not metabolize the products, although the interaction occurs in a gentle environment.

Published
1993

9. Synthesis and molecular structure of 1,4,5,8-tetramethyl(6)(9, 10)anthracenophane: the smallest 9,10-bridged anthracene

Author

Yoshito Tobe, Hideaki Ishii, Shinji Saiki, Kiyomi Kakiuchi, and Koichiro Naemura

Subjects
Aromatic compounds, Cyclophanes -- Analysis, Molecular structure -- Analysis, Isomerization -- Observations, Chemistry
Abstract

Anthracenophanes instantly undergo air oxidation, although the central aromatic ring of its compounds is only a little deformed from planarity. This is in contrast to the benzolog, paracyclophane. Also H NMR spectrum of the anthracenophane derivative at 30 degrees Celsius shows three signals for methylene protons, revealing that the flipping of methylene bridge is faster on the NMR time scale. As the temperature is lowered, the signals broaden, thus enabling methylene proton to appear at delta-1.89 parts per million at -90 degrees Celsius.

Published
1993

10. Azophenolic acerands having chiral 1-phenyl-cis-1,2-cyclohexanediol units: a correlation between enantiorecognitive coloration and host-guest complementarity

Author

Koichiro Naemura, Koji Ueno, Sachiko Takeuchi, Yoshito Tobe, Takahiro Kaneda, and Yoshiteru Sakata

Subjects
Chirality -- Analysis, Quinone -- Research, Chemistry
Abstract

A correlation between the enantiorecognitive coloration of indicator 1, and the complementarity defined by the association constants including the CPK modeling, has been established. Quinone hydrazone-azophenol tautomerization from optically pure 1-phenyl-cis-1,2-cyclohexanediol with a known absolute configuration, protection of the diol with CH2(OCH3)2, etherification with diethylene glycol ditosylate/NaH, deprotection, cyclization with 1, 4-dimethoxy-2,6-bis(bromomethyl)benzene and oxidation with ceric ammonium nitrate and 2,4-dinitrophenylhydrazonation, were used to synthesize two enantiomeric chiral acerands.

Published
1993

21. Site-Selective Guest Inclusion in Molecular Networks of Butadiyne- Bridged Pyridino and Benzeno Square Macrocycles on a Surface.

Author

Tahara, Kazukuni, Lei, Shengbin, Mamdouh, Waet, Yamaguchi, Yui, Ichikawa, Tomoyuki, Uji-i, Hiroshi, Sonoda, Motohiro, Hirose, Keiji, De Schryver, Frans C., De Feyter, Steven, and Yoshito Tobe

Subjects
*ACETYLENE, *MACROCYCLIC compounds, *COAL gas, *MOLECULES, *MACROMOLECULES, *HETEROCYCLIC compounds
Abstract

The article presents a study on site-selective guest inclusion in molecular networks of butadiyne-bridged pyridino and benzeno square macrocycles on a surface. It states that alignment of functional molecules on two-dimensional (2D) molecular networks on solid surfaces is of current concern owing to possible nanotechnological applications, like the fabrication of molecular scale devices and machines.

Published
2008
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