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We developed a photo-chemical coupling reaction of α-keto esters with several simple alcohols, alkanes, ethers, and amides. Use of tertiary alkyl ester, α-cumyl ester, is the key for avoiding the known photo-degradation process. Intermolecular C–H bond activation and subsequent C–C bond formation were promoted by irradiation with an LED lamp (365 nm) without any additives. Among the coupling partners, reactions with sterically less demanding amides proceeded efficiently to provide unique N-acyl-β-amino-α-hydroxy acid derivatives. In benzene or acetone as a solvent, the reaction with a solid amino acid derivative provided a precursor of tetrahydro-1,4-diazepine-2,5-dione derivatives.

The reaction of α,β-disubstituted ( E )- o -(trimethylsilylethynyl)styrenes with a substoichiometric amount of diisobutylaluminum hydride at 100 °C gave 1,2,3-trisubstituted naphthalenes. This benzocyclization is initiated by regioselective hydroalumination of the alkyne moiety, and the resultant alkenylaluminums lead to naphthalenes through intramolecular carboalumination, skeletal rearrangement, and dehydroalumination steps. The silylated products could be efficiently transformed into iodinated polycyclic aromatic hydrocarbons.

Substitution reactions between a phosphoroselenoyl chloride and Grignard reagents proceeded smoothly at the phosphorus atom to furnish phosphonoselenoic acid esters. The resulting mixture of diastereoisomers could be readily distinguished on the basis of 31P NMR, and separated by recrystallization or column chromatography to afford diastereoisomerically enriched products. For one of these diastereoisomers, the absolute configuration was determined by carrying out a single-crystal X-ray diffraction analysis.

Reaction of the title ylide with simple aldehydes and ketones affords the expected Wittig products as mixtures of EIZ-isomers.

Two novel compounds 1 and 2, along with two known ones (3 and 4) were isolated from the edible mushroom Mycoleptodonoides aitchisonii. The structures of 1–4 were determined and identified by interpreting their spectroscopic data. All the compounds showed protective activity against endoplasmic reticulum stress-dependent cell death.

3,4-Disubstituted, 3-substituted, and 4-substituted carbazoles, advanced intermediates in the synthesis of natural carbazole alkaloids, are regioselectively synthesized by Diels—Alder reactions of indolines with alkynes.

An easily recoverable and recyclable heterogeneous catalyst renders possible the synthesis of secondary amines from azobenzenes (I) and alcohols (II) or (IV) under mild reaction conditions.

Photoirradiation (λ > 300 nm) of TiO2 loaded with Pd nanoparticles (2 wt%, ca. 5 nm diameter) in water containing benzyl alcohol and nitrobenzene at room temperature successfully produces the corresponding secondary amine (N-benzylaniline) with 96% yield. This is achieved via three consecutive catalytic reactions: (i) photocatalytic oxidation of alcohol (aldehyde formation) and reduction of nitrobenzene (aniline formation); (ii) catalytic condensation of the formed aldehyde with aniline on the TiO2 surface (imine formation); and, (iii) photocatalytic hydrogenation of the formed imine (secondary amine formation). This catalytic system successfully produces several kinds of secondary amines, even those containing reducible substituents such as –CN, –COOH, or –CHO with >76% yields.

Natural products are often attractive and challenging targets for synthetic chemists, and many have interesting biological activities. However, synthetic chemists need to be more than simply suppliers of compounds to biologists. Therefore, we have been seeking ways to actively apply organic synthetic methods to chemical biology studies of natural products and their activities. In this personal review, I would like to introduce our work on the development of new biologically active compounds inspired by, or extracted from, the structures of natural products, focusing on enhancement of functional activity and specificity and overcoming various drawbacks of the parent natural products.

Pd-catalyzed cyclization of substrates (I) provides vinyl indolines, which are further transformed into intermediates of indole alkaloids such as (III) or (IV).

Pyromellitic diimide is incorporated into graphitic carbon nitride, g-C3N4 by calcination of a mixture of melem and pyromellitic dianhydride at 598 K for 4 h.

The reaction of o-(trimethylsilylethynyl)styrenes with diisobutylaluminum hydride efficiently provides trimethylsilyl-1H-indenes.

Four novel compounds, makomotines A to D ( 1 – 4 ), along with two known ones ( 5 , 6 ) were isolated from Makomotake, Zizania latifolia infected with Ustilago esculenta . The structures were determined or identified by the interpretation of spectroscopic data. Compound 1 suppressed the formation of osteoclast without toxicity.

Palladium-catalyzed decarboxylative coupling of benzoic acid derivatives with arylboroxins gave biaryls using a catalytic amount of Pd(TFA) 2 –hydrazone 1d system with Ag 2 CO 3 at 80 °C in good yields. We also found that decarboxylative coupling with aryl(trialkoxy)silanes gave biaryls using a Pd(TFA) 2 –hydrazone 1g system with AgF in good yields.

Treatment of bromodienes with trimethylaluminum in the presence of a palladium catalyst with tricyclohexylphosphine as ligand leads to geometrically pure methyl-branched conjugated dienes.

A highly stereoselective palladium(II)-catalyzed intramolecular cyclization of 1,11-dihydroxyundec-9-en-5-one derivatives via unstable hemiacetal intermediates is reported.

The borylated products (III) and (V) can be readily converted to the corresponding boronic acids under acidic conditions.

A novel sphingosine, 1,2-diacetylsphingosine (1), was isolated from the edible mushroom Grifola gargal. The structure of 1 was determined by the interpretation of spectroscopic data. Compound 1 suppressed the formation of osteoclast without toxicity.

Three novel lettuce hypocotyl and root growth regulating compounds, armillariols A (I), B (II), and C (III), are isolated from the culture broth of Armillaria sp.

Visible-light irradiation (

A mixture of α-Ag0.79VS2 and β-Ag0.79VS2 is prepared by solid state reaction of a stoichiometric mixture of Ag, V, and S powder (evacuated quartz tube, 750 °C, 6 d).

The structure and elementary physical properties of a new intermetallic compound, β - HfCuGe , are reported. β - HfCuGe has a tetragonal structure (space group I4/mmm) with lattice constants of a=3.7634(11)A and c=13.499(4) A. The structure, which consists of double layers of Hf stacked with edge-sharing CuGe4 squares, is not typical for intermetallic compounds and appears to be a new structure type. The compound is a weak paramagnet and a normal metal down to 0.4 K.

The method renders possible the access to various unsymmetrical target compounds as exclusive (E)-isomers.

Carbon—nitrogen and carbon—sulfur bond forming reactions of haloarenes (I) and (VI) with secondary amines (II) and benzenethiols (IV) and (VII) are performed under heterogeneous conditions utilizing immobilized palladium complexes coordinated with a amphiphilic resin-supported phosphane ligand to provide aryl(dialkyl)amines (III) and diaryl sulfides (V) and (VIII) in satisfactory to very good yields.

In the reaction with the thioglycoside acceptor (II), electron-donating groups on the galactose donor (I) can prevent the aglycone-transfer (AGT) reaction.

CuI as co-catalyst and hydrazone BIH as the ligand render possible the preparation of various diarylalkynes in the presence of low amounts of Pd catalyst.

UV irradiation of TiO2 loaded with bimetallic Pd–Pt alloy particles promotes highly efficient dehalogenation of organic halides with alcohol as a hydrogen source.

In the case of N-tosyl-substituted substrates, the title cycloisomerization requires a platinum catalyst to promote the reaction.

The title transformation is achieved via a Pt-assisted photocatalytic oxidation of alcohols (II) and a catalytic condensation of the aldehyde intermediates with amines (I) on the TiO2 surface.

Catalytic amination of aryl bromides with primary amines is achieved in water under heterogeneous conditions in the presence of a palladium catalyst which is anchored to the amphiphilic PS-PEG resin to provide a series of triarylamines without metal-contamination.

The total synthesis of 2-deoxy-D-ribose (VIII) is achieved in 12 steps from L-(-)malic acid (I) via an unstable hemiacetal.

The oxidation of chemically vapor-deposited SiC in wet O2 (water vapor partial pressure = 0.01 MPa, total pressure = 0.1 MPa) was examined using a thermogravimetric technique in the temperature range of 1823 to 1923 K. The oxidation kinetics follow a linear-parabolic relationship over the entire temperature range. The activation energies of linear and parabolic rate constants were 428 and 397 kJ · mol−1, respectively. The results suggested that the rate-controlling step is a chemical reaction at an SiC/SiO2 interface in the linear oxidation regime, and the rate-controlling step is an oxygen diffusion process through the oxide film (cristobalite) in the parabolic oxidation regime.

Systematic studies of the effect of the neighbouring phosphonate group on the reactivities of carbene showed that the neighbouring phosphonate group exerts prominent effects on both the product distribution and the reaction products; the results are interpreted as indicating the extent of participation, which seems to be sensitive to the carbenic substituents.