A5054753108- Glass properties and applications
- Luminescence Properties of Advanced Materials
- Synthetic Organic Chemistry Methods
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Inorganic Fluorides and Related Compounds
- Marine Sponges and Natural Products
- Solid-state spectroscopy and crystallography
- Oxidative Organic Chemistry Reactions
- Chemical synthesis and alkaloids
- Asymmetric Synthesis and Catalysis
- Microbial Natural Products and Biosynthesis
- Iron-based superconductors research
- Optical properties and cooling technologies in crystalline materials
- Sperm and Testicular Function
- Solid State Laser Technologies
- Fungal Biology and Applications
- Reproductive Biology and Fertility
- Phase-change materials and chalcogenides
- Traditional and Medicinal Uses of Annonaceae
- Cyclopropane Reaction Mechanisms
- Lanthanide and Transition Metal Complexes
- Natural product bioactivities and synthesis
- Bioactive Natural Diterpenoids Research
- Advanced Synthetic Organic Chemistry
Tokyo University of Pharmacy and Life Sciences
2018-2024
Astellas Pharma (Japan)
2017-2022
Kyoto University
1991-2016
The University of Tokyo
2007-2014
University of the Ryukyus
2011-2014
Kagoshima University
2013
Chubu University
2013
Inuyama Chuo Hospital
2010
University of Shizuoka
2007-2008
Nagoya University
2002-2003
Abstract Meroterpenoids isolated from fungi of the Ganoderma family have received much attention owing to their unique structures and diverse biological activities. A number meroterpenoids been since 2000 many total syntheses synthetic studies reported. In this review, we highlight fifteen conducted 2014 2023 polycyclic classified according connection pattern dihydroquinone with terpenoid structure. The selected illustrate how molecular complexity was constructed by tactics.
Spectroscopic properties of Er3+ in Ga2S3–GeS2–La2S3 glasses are investigated on the basis spontaneous emission probabilities calculated by use Judd–Ofelt theory and lifetime data. Frequency upconversion spectra also measured with excitation at 800 980 nm. The much larger than those other glass systems such as oxides fluorides. This is mainly attributed to large refractive indices sulfide glasses. quantum efficiencies I11/24 F9/24 levels comparable or typical values a fluoride glass....
To gain insight into the unconventional superconductivity of Fe pnictides with no electron pockets, we measure thermal conductivity $\ensuremath{\kappa}$ and penetration depth $\ensuremath{\lambda}$ in heavily hole-doped regime Ba${}_{1\ensuremath{-}x}$K${}_{x}$Fe${}_{2}$As${}_{2}$. The residual ${(\ensuremath{\kappa}/T)}_{T\ensuremath{\rightarrow}0\phantom{\rule{0.28em}{0ex}}\mathrm{K}}$ $T$ dependence consistently indicate fully gapped at $x=0.76$ (line) nodal higher hole concentrations....
The total synthesis of lucidumone (1), a Ganoderma meroterpenoid, was accomplished in racemic form from easily prepared 6 and 7 10 steps as the longest linear sequence. completed through one-pot preparation tetracyclic core skeleton by Claisen rearrangement followed an intramolecular aldol reaction. reaction allowed for stereocontrolled construction bicyclo [2.2.2] octane fused to indanone structure. enantioselective 1 also described via chiral transfer strategy rearrangement.
We have investigated the decay processes of Er:4S3/2 and F39/2 states mechanisms frequency upconversion under 800 nm excitation Er3+ in ternary ZrF4–BaF2–LaF3 glasses. The F49/2 are discussed on basis Er concentration dependence fluorescence lifetime. quantum efficiencies emission S43/2 73% 25%, respectively. difference between these can be explained from multiphonon rates: rate state is much smaller than that state. relaxation a dominant nonradiative process A self-quenching at high...
The stereoselective synthesis of the key intermediate for altemicidin has been accomplished. commenced with a bicyclo[3.3.0] framework, which was readily obtained via an intramolecular C−H insertion reaction. A Curtius rearrangement employed as step to stereoselectively construct β-hydroxyl α-disubstituted-α-amino acid structure. Synthesis vinylogous urea achieved using hydrolysis nitrile intermediate.
The asymmetric total synthesis of lemnalemnane A, a rare rearranged sesquiterpenoid, has been accomplished in 13 steps from (S)-carvone. key features the are removal isopropenyl group derived (S)-carvone via radical intermediate, formation bicyclo[3.3.1]nonane skeleton using Dieckmann condensation, stereocontrolled construction five continuous chiral centers by chemo- and stereoselective reduction introduction alkyne group, spirolactone moiety hemiacetal intermediate.
Molecular dynamics simulation was performed on barium meta-fluorozirconate, BaZrF6, glass by using the Born–Mayer–Huggins pair potential. The cumulative F coordination numbers and correlation functions of Zr Ba ions revealed that, in simulated BaZrF6 glass, number mean distance nearest neighboring were about eight at 2.12 Å for ten 2.75 ions. This is consistent with previous x-ray diffraction result glass. A little uncertainty number, however, may admit presence small amounts seven...
Optical properties of Er3+ -doped fluoride glasses in the pseudoternary systems MFn–BaF2–YF3, where M is Zr, Hf, Al, Sc, Ga, In, or Zn, were investigated, and variation local structure was discussed. Of three Judd–Ofelt Ωt parameters (t = 2, 4, 6) that dominate f–f transition probabilities ions, Ω2 increased as cationic field strength network-forming Mn+ ions increased. Ω6 showed a correlation with Er—F bond length. The intensity 4S3/2→4I15/2 green upconversion luminescence at 0.55 μm...
Optical absorption and emission properties of Er3+ ions in ZnCl2-based glasses are investigated. The electric dipole line strengths for various transitions were estimated from the measured optical spectra. spontaneous probabilities predicted using Judd–Ofelt theory. Among Ωt (t=2, 4, 6) phenomenological intensity parameters, Ω2 value is larger than that ZrF4-based glass. On contrary, Ω4 Ω6 values comparatively small. Multiphonon relaxation rates follow a so-called “energy-gap law” which...
Spectroscopic properties of Ho3+-doped ZnCl2-based glasses are investigated. The Ω2 value the glass is especially large compared with those in fluoride while Ω4 and Ω6 parameters relatively small. Decay measurements for three excited states F55, S25+F45, F2,35+K83 were performed multiphonon relaxation (MPR) rates respective estimated. experimental data approximately on a line expressed by WMPR=C exp(−αΔE) C=5.0×107 s−1 α=4.0×10−3 cm. host-dependent constant C very small, contributing to high...
Immiscibility temperatures of Na 2 O‐B O 3 ‐SiO glasses, with andwithout 1 mol% MoO , additions, were determined and the effect additions on 65O°C immiscibility isotherms was established. In addition, temperature phase‐separation morphology an glass progressive investigated. It found that addition small amounts extends boundary system raises by ∼l8°C for each mol % addition. Analysis suggests do not significantly alter tie lines phase separation in system, although such cause a lowering...
Total synthesis of SB-203207 (1) was achieved, beginning with a desymmetrical C–H insertion reaction diazoester bearing our recently developed chiral auxiliary. Utilizing the optically active bicyclo[3.3.0]octane ring, four stereogenic centers were efficiently constructed in sequence. Finally, mild oxidation 27 to carboxylic acid via cyanohydrin intermediate and hydrolysis cyanide carboxyamide presence labile enamide group completed an efficient total 1.
The first total synthesis of the tricyclic meroterpenoid applanatumol B, isolated from Ganoderma applanatum, was accomplished in 14 steps 2,5-dimethoxybenzaldehyde and 4-pentyn-1-ol. synthetic features include an intramolecular Morita–Baylis–Hillman reaction, a stereoselective Michael addition, efficient construction skeleton under acidic conditions involving epimerization at α-position ketone.
In earlier work, a prediction method of the immiscibility boundary ternary silicate glass system was developed involving two known binary boundaries and measured temperature one composition. present is extended to case where not applied as an example systems containing K 2 O. First, O‐SiO estimated by measuring temperatures three glasses in O‐Li O (or Na O)‐SiO . Using this result , O‐Na O‐BaO‐SiO are estimated. The results agree reasonably well with experimentally determined at selected...
A novel chiral 1,3-diketone possessing C2 symmetry was synthesized and utilized in the asymmetric synthesis of guignardone H I by employing sequential condensation–6π-electrocyclization reactions with followed stereoselective hydrogenation as key steps. Although synthetic compounds differed from natural I, we realized that C4-epimers proposed structures for were actual structures.