A5090373363- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Crystallography and molecular interactions
- Asymmetric Synthesis and Catalysis
- Photochromic and Fluorescence Chemistry
- Molecular spectroscopy and chirality
- Axial and Atropisomeric Chirality Synthesis
- Oxidative Organic Chemistry Reactions
- Catalytic C–H Functionalization Methods
- Catalytic Cross-Coupling Reactions
- Origins and Evolution of Life
- Luminescence and Fluorescent Materials
- Synthesis and Reactivity of Heterocycles
- Porphyrin and Phthalocyanine Chemistry
- Advanced Synthetic Organic Chemistry
- Asymmetric Hydrogenation and Catalysis
- Synthesis of Organic Compounds
- Synthetic Organic Chemistry Methods
- Radical Photochemical Reactions
- Alkaloids: synthesis and pharmacology
- Chemical synthesis and alkaloids
- Nanoplatforms for cancer theranostics
- Organic Chemistry Cycloaddition Reactions
- Synthesis and Biological Evaluation
- Organic Light-Emitting Diodes Research
Tokushima University
2016-2025
National Hospital Organization Kyushu Cancer Center
2020
Photonics (United States)
2020
Chiba University
2010-2015
Shizuoka University
2013-2015
Graduate School USA
2014
Institute for Analytical Instrumentation
2013
Redox enzymes play a central role in generating structural complexity during natural product biosynthesis. In the postassembly tailoring steps, redox cascades can transform nascent chemical scaffolds into structurally complex final products. Chaetoglobosin A (1) is biosynthesized by hybrid polyketide synthase–nonribosomal peptide synthetase. It belongs to chaetoglobosin family of products, comprising many analogs having different degrees oxidation introduced their We report here...
Understanding enzymatic Diels-Alder (DA) reactions that can form complex natural product scaffolds is of considerable interest. Sch 210972 1, a potential anti-HIV fungal product, contains decalin core proposed to through DA reaction. We identified the gene cluster responsible for biosynthesis 1 and heterologously reconstituted biosynthetic pathway in Aspergillus nidulans characterize enzymes involved. Most notably, deletion cghA resulted loss stereoselective formation, yielding both an endo...
Abstract As dimeric natural products frequently exhibit useful biological activities, identifying and understanding their mechanisms of dimerization is great interest. One such compound (−)‐ditryptophenaline, isolated from Aspergillus flavus , which inhibits substance P receptor for potential analgesic anti‐inflammatory activity. Through targeted gene knockout in A. heterologous yeast expression, we determined the first time cluster pathway biosynthesis a diketopiperazine alkaloid. We also...
Separated: 3-Hydroxy-3-phenylisoindolin-1-ones have been resolved by dynamic preferential crystallization. The compounds were effectively racemized through ring-opening and ring-closing reactions via achiral intermediates under basic conditions. Crystallization from a toluene solution containing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with stirring evaporation of the solvent gave optically active crystals quantitatively high ee values. Detailed facts importance to specialist readers are...
A remarkably effective method allowing an extremely high enantioselective synthesis of the spiro-fused 2-oxindole/α-methylene-γ-butyrolactones is described. The key strategy lies in use indium-catalyzed asymmetric amide allylation N-methyl isatin with functionalized allylstannanes, which can lead to antineoplastic spirocyclic lactones almost enantiopure forms.
Abstract This article is a full account of the work exploring potential utility catalytic enantioselective amide allylation various isatins using indium‐based chiral catalysts. A survey isatin substrates and NH‐containing stannylated reagents revealed that reaction has remarkably wide scope to result in extremely high yields enantioselectivities (up >99 %, 99 % ee ) variously substituted homoallylic alcohols. Several mechanistic investigations demonstrated substrate–reagent hydrogen‐bond...
We have synthesized naphthalene-fused imidazo[1,2-a]pyridines by a novel electrophilic iodocyclization of 2-alkynyl-3-arylimidazo[1,2-a]pyridines. Notably, their quaternized salts exhibited green emission with unexpectedly high quantum yields and mega-large Stokes shift were successfully used for mitochondrial imaging.
Abstract Chiral organic salts, composed of a specific chiral cyclic β-aminoguanidine and an optional achiral phosphoric acid diester, were designed demonstrated to serve as readily accessible, noncovalently tunable, versatile asymmetric organocatalysts. These catalysts facilitated the Brønsted base-catalyzed reaction between malonates nitroolefins Lewis aldehydes maleimides. DFT calculations supported salt’s predicted structure, revealing that host’s guanidine moiety interacts with guest...
Optically active materials could be generated by simple solidification of achiral without an external chiral source. When cis-3,4-diphenylsuccinimides were solidified in the presence a catalytic amount DBU evaporating solvent with stirring, optically trans-3,4-diphenylsuccinimides obtained quantitatively high enantiomeric excesses.
The irradiation of chromone-2-carboxylic esters resulted in the stereo- and regioselective formation C(2) chiral anti-HH dimers from triplet excited state. On contrary, photolysis solid-state gave anti-HT exclusively controlled by molecular arrangement crystal.
N,N-diallyl-4-methyl-1-propyl-2-quinolone-3-carboxamide afforded chiral crystals of a P2(1) crystal system by spontaneous crystallization. The molecular chirality in the was retained after were dissolved solvent at low temperature, and frozen effectively transferred to products two-step reaction involving hydrogenation intermolecular photocycloaddition reactions.
Abstract A series of fluorescent dimeric imidazo[1,5‐ a ]pyridinium salts have been synthesized. These displayed large Stokes shifts (up to 196 nm), possessed good water solubility, and exhibited blue yellow emission ( Φ em =up 0.50) in solution. When one specific compound was used for co‐incubation HeLa cells, green signals were observed. The combined use the salt commercially available dye realized double staining cells under single UV excitation.
Crystal structures and photochemical reactions of three N,N-diallyl-2-quinolone-3-carboxamides were investigated. One quinolonecarboxamide afforded chiral crystals a P21 crystal system by spontaneous crystallization, the molecular chirality in was effectively transferred to cyclobutane 96% ee an intramolecular 2 + photocycloaddition reaction solid state.
Abstract We report a new catalyst system, morpholine–Pd(OAc) 2 complex, for Suzuki–Miyaura coupling of aryl tosylates or mesylates with arylboronic acids to give biaryl compounds. The system is proposed be precursor the catalytically active species in reaction. Aryl chlorides and triflates can also used this Altogether, 22 compounds were obtained using system.
X-Ray crystallographic analysis of N-(1-naphthyl)-2(1H)-pyrimidinethione revealed that the space group was tetragonal and chiral P43. The rate racemization due to C–N bond rotation considerably influenced by solvent properties. A nonpolar lowers ΔG‡value about 3.0 kcal mol−1 relative value in a polar or protic solvent. crystallization racemic axially pyrimidinethione at high temperature led breaking symmetry up 91% ee.
Getrennt: Die Racematspaltung von 3-Hydroxy-3-phenylisoindolin-1-onen gelang mit der Methode bevorzugten Kristallisation. Verbindungen wurden durch Ringöffnungs- und Ringschlussreaktionen über achirale Intermediate effektiv racemisiert. Nach Kristallisation aus Toluol 1,8-Diazabicyclo[5.4.0]undec-7-en (DBU) Verdampfen des Lösungsmittels optisch aktive Kristalle quantitativ hohen ee-Werten erhalten. Detailed facts of importance to specialist readers are published as ”Supporting Information”....
Abstract We designed a new class of N ‐type ligands bearing an imidazo[1,5‐ ]pyridine moiety and synthesized seven derivatives. The palladium‐catalyzed Mizoroki–Heck reaction aryl bromides chlorides with alkenes using our ]pyridine‐PdCl 2 system afforded the desired products in good‐to‐high yields low palladium loadings short times.
Copper-catalyzed C-C coupling reaction of aryl iodides with diethylmalonate in toluene at 90 ˚C gave arylated malonates using 5 mol% CuI hydrazone 1a as a ligand good yields under an aerobic atmosphere. We also found CuI/hydrazone 1b to be efficient catalytic system for C-O reactions bromides phenols give ethers 110
N-(2-methoxy-1-naphthoyl)pyrrolidine afforded chiral crystals by spontaneous crystallization. The molecular chirality in the crystal was retained after dissolving a cooled solvent. Kinetic resolution of racemic amines performed using provisional conformation derived from crystals.
N,N'-Dimethylated imidazo[1,5-a]pyridinium salt having good water solubility and exhibiting fluorescence emission was found to work as not only a bioimaging agent but also therapeutic under UVA-LED irradiation conditions. Because the continuous HeLa cells stained by synthesized resulted in cell death due mitochondrial damage, has potential application photodynamic therapy against tumor cells.
Abstract An asymmetric photoreaction by using chirality provided dynamic chiral salt formation was demonstrated. Crystallization of racemic 2‐quinolone‐3‐carboxamide and 2‐quinolone‐4‐carboxamide with enantiopure L ‐dibenzoyltartaric acid led to deracemization gave high diastereomeric excess values the crystalline salts in almost quantitative yield. The axial retained for a long period time after were dissolved cooled solvent. frozen derived from effectively transferred products typical...
This communication reports a significant breakthrough on the novel catalytic amide allylation to acyclic α-ketoester systems, achieving satisfactorily high yields and extremely levels of asymmetric induction allow for highly enantioselective synthesis ester functionalised α-methylene-γ-butyrolactones.
Irradiation of three chromone-2-carboxamides with a chiral auxiliary resulted in diastereoselective formation C2-chiral anti-HH dimer scaffold. Selection the solvent polarity and decreasing temperature asymmetric induction up to 84% diastereomeric excess (de).