A5066525722- Asymmetric Synthesis and Catalysis
- Chemical Synthesis and Analysis
- Synthetic Organic Chemistry Methods
- Synthesis and Catalytic Reactions
- Catalytic C–H Functionalization Methods
- Essential Oils and Antimicrobial Activity
- Chemical Synthesis and Reactions
- Synthesis of Organic Compounds
- Asymmetric Hydrogenation and Catalysis
- Oxidative Organic Chemistry Reactions
- X-ray Diffraction in Crystallography
- Catalytic Cross-Coupling Reactions
- Cyclopropane Reaction Mechanisms
- Enzyme Catalysis and Immobilization
- Crystallization and Solubility Studies
- Phytochemicals and Antioxidant Activities
- Subcritical and Supercritical Water Processes
- Bioactive natural compounds
- Chemical synthesis and alkaloids
- Synthesis and properties of polymers
- Advanced Synthetic Organic Chemistry
- Biological Activity of Diterpenoids and Biflavonoids
- Carbohydrate Chemistry and Synthesis
- Pharmacological Effects of Natural Compounds
- Synthesis and Characterization of Heterocyclic Compounds
Kitami Institute of Technology
2016-2024
Muroran Institute of Technology
2010-2016
Enantioselective Diels-Alder reactions of 1,2-dihydropyridines with acroleins using a novel chiral oxazolidine organocatalyst afforded isoquinuclidines that is an efficient synthetic intermediate oseltamivir, fairly good chemical yield and excellent enantioselectivity (90%, up to >99% ee).
The enantioselective Diels-Alder reaction of 1,2-dihydropyridines with aldehydes using an easily prepared optically active β-amino alcohol catalyst was found to provide isoquinuclidines, efficient synthetic intermediate pharmaceutically important compounds such as oseltamivir phosphate, a satisfactory chemical yield and enantioselectivity (up 96%, up 98% ee). In addition, the obtained highly pure isoquinuclidine converted piperidine having four successive carbon centers.
Enantioselective aldol reactions of various isatins with ketones using newly designed amino amide organocatalysts were found to provide chiral 3‐substituted 3‐hydroxy‐2‐oxindoles in good excellent yields and stereoselectivities (up 99 %, up 98 % ee , syn/anti = 99:1); one catalyst, 3i proved particularly successful. One the resulting oxindoles, 3‐hydroxy‐3‐(2‐oxocyclohexyl)‐2‐indolinone may serve as a synthetic intermediate for pharmaceutically important compounds and, its own right, shows...
Abstract The catalytic activity of a simple amino alcohol that contains bulky super silyl group [i.e., tris(trimethylsilyl)silyl (TTMSS)] bonded to the oxygen atom at γ‐position along with primary amine moiety was examined in enantioselective 1,3‐dipolar cycloaddition nitrones α,β‐unsaturated aldehydes. organocatalyst successfully provided optically active isoxazolidines good chemical yields (up 86 %) excellent diastereoselectivities ( endo / exo , up 96:4) and enantioselectivities 97 % ee...
Abstract The Ru‐catalyzed dehydrogenative silylation of 2‐alkyloxazolines with 1,1,1,3,5,5,5‐heptamethyltrisiloxane took place site‐selectively at methyl C(sp 3 )−H bonds located γ to the nitrogen atom oxazolyl groups. Pyridine and pyrazole rings could also be used as a directing group. A catalytic mechanism based upon successive σ‐bond metathesis is proposed.
The intramolecular dehydrogenative cyclization of 2-(dialkylsilyl)biaryls proceeded in the presence a catalytic amount platinum(II) chloride and potassium tris(3,5-dimethyl-1-pyrazolyl)borohydride to give good yields corresponding dibenzosilole derivatives.
The present study provides valuable data that the herbal water byproduct of Japanese peppermint, produced during steam distillation extraction an essential oil, can be utilized as antibacterial agent. major ingredient in from peppermint 'Hokuto' was menthol, with a concentration close to its solubility. showed excellent efficacy against typical gram-negative and gram-positive bacterial strains Escherichia coli Staphylococcus aureus, respectively, maintained even when diluted up appropriate...
Synthesis of bicyclic compounds was achieved via a lipase-catalyzed, stereoselective, domino Michael–aldol reaction 2-methyl-1,3-cycloalkanedione and methyl vinyl ketone. Appropriate conditions, including the type enzyme, solvent, temperature, were determined. In addition, effects solvent polarity addtives investigated. The proceeded in presence lipase AS solution 20% acetone dimethylsulfoxide (DMSO) at 10 °C for 8 days, followed by addition p-toluenesulfonic acid (TsOH) to afford 51–83%...
The enantioselective Diels-Alder reactions of 1,2-dihydropyridines with acroleins using a chiral primary amino silyl ether organocatalyst afforded isoquinuclidines good chemical yields and excellent enantioselectivities (up to 70% up 99% ee).
The yield and composition of Japanese peppermint (Mentha arvensis L.) essential oil obtained by solvent-free microwave extraction were determined compared with those traditional hydrodistillation. was in 0.88-0.95 % treatment at 100-500 W for 20-90 min, these yields are similar to Thus, is a suitable distillation method the oils from peppermint.
Stereoselective synthesis of warfarin by promiscuous lipase-catalyzedMichael reaction 4-hydroxycoumarin to benzylideneacetone has been developed.The best result was obtained using lipase AS as a catalyst in anhydrous DMSO with 1:3 molar ratio at 20 ºC for 7 days.The yield and enantiomeric excess were 85% 45% ee (R-form), respectively.
In this study, we provide a method for obtaining essential oil from Mentha arvensis L. in large quantities. Three types of polysaccharide-degrading enzymes were investigated, namely cellulase A "Amano" 3, T 4, and hemicellulase 90. The optimum extraction conditions the combined use 2 wt% 90, 3 h incubation. Enzymeassisted increased amount 2.2 mL to 3.0 mL, compared with extracted without an enzyme.
Chiral primary amino amide organocatalysts were designed and synthesized as new for the enantioselective Michael addition of 4-hydroxycoumarin with !,"-unsaturated ketones to produce chiral warfarin (up 56% ee up 92% yield).
Thermal stabilities of four major components (l-menthol, l-menthone, piperitone, and l-menthyl acetate) Japanese mint essential oil were evaluated via subcritical water treatment. To improve experimental throughput for measuring compound stabilities, a small-scale treatment method using ampoule bottles was developed employed. A mixture the treated in at 180–240 °C 5–60 min, then analyzed by gas chromatography. The results indicated that order thermal resistance, from strongest to weakest,...
Asymmetric conjugate addition-cyclization of lithium amide 6-membered hydrazine 4, piperidazine, (or 5-membered 6, pyrazolidine) to N-(E)-cinnamoyl-(1S)-2,10-camphorsultam (1S)-3 afforded -amino acid derivative (S)-1 {or (S)-2} for the synthesis polyamine alkaloids in good yield with stereoselectivity (up 86% ee).A number acids have been isolated free form and show interesting pharmacological properties. 1 In addition, many classes natural products contain derivatives as...
Preparation of the tripeptide catalystsCondensation between Cbz-Pro-OH and amino ester hydrochloride: To a solution (20.0 mmol, 4.985 g) in CH2Cl2 (100 mL), Amino hydrochloride mmol), HOBt (22.0 2.973g), EDCI (22 3.9 mL) NMM (40 4.4 was added at 0 °C.The reaction mixture stirred room temperature for 12 h.The resulting concentrated under reduced pressure diluted by ethyl acetate.The washed with saturated aqueous NaHCO3 1M HClaq brine.The Organic phase dried over Na2SO4.After removal solvent...
Biflavones having a A ring-A ring of two flavone units were easily prepared by using Suzuki cross-coupling reaction borylated flavones with bromoflavones or flavone-5-triflate in good to excellent yields.
The enantioselective Diels-Alder (D-A) reaction between N-phenoxycarbonyl-or N-benzyloxycarbonyl-1,2-dihydropyridine (1a or 1b) and N(2)-acryloyl-N(1)-(1-naphthylmethyl)-5,5-dimethylpyrazolidin-3-one (2b) using (S,S)-bisoxazoline-Cu(II) catalyst (A, B, C D) has been investigated.Utilizing (S,S)-t-Bu-bisoxazoline-Cu(II) C, the D-A of 1a 2 afforded endo-(7S)-isoquinuclidines (3, 4 5) in good chemical yields with high enantioselectivity (up to 99% e.e.).
Japanese mint (Mentha arvensis) is a widely used herb for culinary, fragrant, and medicinal applications. In this study, useful substances were obtained from leaves by extraction using subcritical water (180 to 260 °C). The characteristics of the extracts, including carbohydrates, proteins, phenolic content, as well 2′,2′-diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity investigated. highest carbohydrate content was at 180 °C, while amount protein 200 °C. A linear relationship...
Subcritical water treatment with pressure-releasing distillation was proposed as a method to obtain essential oil from Japanese mint (Mentha arvensis L. var. piperascens Malinv. cv.). The extraction and fractionation were carried out between 100 °C 220 °C, times of 5 60 min investigated. Quantitative analysis volatile component conducted by gas chromatography. yields both l-menthol l-menthone converged in the initial fractions temperature increased. l-menthol, l-limonene, l-menthone,...