Showing papers by "Chizuko Kabuto published in 1998"
TL;DR: In this paper, a series of optically active macrocyclic amides consisting of the chiral unit and a dianiline spacer were synthesized by one-pot procedures, and their structures were compared by spectroscopy and X-ray crystallography.
Abstract: Helical chiral 1,12-dimethylbenzo[c]phenanthrene-5,8-dicarboxylic acid was synthesized and resolved in multigram quantities. The absolute configuration was determined by X-ray analysis of the bis(camphorsultamamide) derivative. A series of optically active macrocyclic amides consisting of the chiral unit and a dianiline spacer were synthesized by one-pot procedures, and their structures were compared by spectroscopy and X-ray crystallography. One of the cycloamides exhibited catalytic activity in the asymmetric addition of diethylzinc to aromatic aldehydes. N-Alkylated derivatives were also synthesized, which possessed folded structures distinct from those of the parent cyclic amides.
56 citations
TL;DR: X-ray crystallographic analysis of 3,3-bis (diisopropylamino)-1,2-bis(trimethylsilyl)-3-silacyclopropene (1) gave the first experimental evidence for significant substituent effects on the ring stru...
29 citations
TL;DR: T4M (M = Si, Ge, Sn; T = tropolonato)-type compounds were synthesized by reactions of tropolone with tetramethoxysilane, tetramerethoxygermane, and tetrachlorostannane, respectively X-ray and NMR an
28 citations
27 citations
TL;DR: A series of oligo(1,1-silole)s, Me3Si[SiC4Me4]n SiMe3 (3: n=3, 4:n = 4, 5:n=5) were synthesized and characterized.
Abstract: A series of oligo(1,1-silole)s, Me3Si[SiC4Me4]n SiMe3 (3: n=3, 4:n=4, 5:n=5) were synthesized and characterized. X-ray diffraction analysis of tersilole 3 revealed that the pentasilane backbone has almost all-trans conformation. The oligo(1,1-silole)s show distinct UV absorptions due to σ-σ*, σ-π*, and π-π* transitions.
26 citations
TL;DR: Alkeneselenolate and alkenetellurolate ions were generated by treating ketone p-toluenesulfonylhydrazones possessing an α-methylene or an αmethine group with t-BuOK and elemental selenium or tellurium, respectively, at 110-150 °C, and were converted into dialkenyl dichalcogenides by aerobic oxidation.
Abstract: Alkeneselenolate and alkenetellurolate ions were generated by treating ketone p-toluenesulfonylhydrazones possessing an α-methylene or an α-methine group with t-BuOK and elemental selenium or tellurium, respectively, at 110-150 °C, and were converted into dialkenyl dichalcogenides by aerobic oxidation.
10 citations
TL;DR: In this paper, the UV spectrum and regioselectivity of the addition reaction of phenols to the disilene were discussed, and the molecular structure of the masked disilenes was also determined by single-crystal X-ray diffraction.
Abstract: (Trimethylsilylmethyl)trimethyldisilene was generated photochemically from 1-phenyl-7-trimethylsilylmethyl-7,8,8-trimethyl-7,8-disilabicyclo[2.2.2]octa-2,5-diene (masked disilene). UV spectrum and regioselectivity of the addition reaction of phenols to the disilene were discussed. The molecular structure of the masked disilene was also determined by single-crystal X-ray diffraction.
2 citations
TL;DR: Alkeneselenolate and alkenetellurolate ions were generated by treating ketone p-toluenesulfonylhydrazones possessing an α-methylene or an αmethine group with t-BuOK and elemental selenium or tellurium, respectively, at 110-150 °C, and were converted into dialkenyl dichalcogenides by aerobic oxidation as mentioned in this paper.
Abstract: Alkeneselenolate and alkenetellurolate ions were generated by treating ketone p-toluenesulfonylhydrazones possessing an α-methylene or an α-methine group with t-BuOK and elemental selenium or tellurium, respectively, at 110-150 °C, and were converted into dialkenyl dichalcogenides by aerobic oxidation.