Total syntheses of natural products: trichodenones A-C, pericosines A-E, and withasomnines had been achieved. Synthesis of marine fungal metabolites of trichodenones determined the relative and absolute configuration of them. From a series of synthetic studies of marine derived carbasugars pericosines A-E, the proposed structure of antitumor pericosine A was revised and the absolute configurations of all natural pericosines were determined. The first total synthesis of pericosine E was realized with a highly regio- and stereoselective epoxidation of the diene with methyl(trifluoromethyl) dioxirane (TFDO) as a key step. Further, a divergent synthesis of plant alkaloids withasomnies and unnatural analogues was carried out using the Suzuki-Miyaura coupling between the final intermediate triflate and commercially available arylboronic acids.

Our efficient catalytic reactions based on the “Borrowing Hydrogen” methodology are described here. Thus, indoles were reacted with alcohols in the presence of Pd/C or RuCl₂(PPh₃)₃/DPEphos catalyst to give the corresponding 3-alkylindoles in good to excellent yields. The Pd/C catalysis also promoted the regioselective alkylation of 4-hydroxycoumarin, barbituric acids and oxindoles with good catalytic efficiency. Reaction of amines with 1,2-diol in the presence of [RuCl₂(p-cymene)]₂/JOSIPHOS catalyst afforded the optically active β-amino alcohols with up to 77% ee. Highly efficient hydroamination of C-C double bond of allylic alcohols was achieved with a combination catalyst of RuClH(CO)(PPh₃)₃ and a pyridine ligand bearing two imine units at its 2,6-position to provide the corresponding γ-amino alcohols in high yield.

Organocatalysts utilize various molecular interactions for catalysis. However, molecular interactions for organocatalysis are in general not as strong as those for metal-catalysis. Thus, because of this character, multiple activations are often necessary to catalyze a reaction, however, in other words, it enables the use of multipoint interactions in the transition state of a catalytic reaction, thereby leading to high stereoselectivity, even if it is a very rapid reaction. On the basis of this concept, we developed asymmetric reactions affording various heterocycles via organocatalytic hetero-Michael additions and the applied synthetic transformations. In order to accomplish high enantioselectivity, we designed reactions utilizing different activation manners by organocatalysts depending on the substrate type; it is a key to utilize simultaneous multipoint interactions between a catalyst and a substrate.

Linear polystyrene was suitable as a stabilizer for metal nanoparticles. Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectrometry (ICP-AES) were used to characterize the metal nanoparticles supported by polystyrene. Linear polystyrene-stabilized PdO nanoparticles (PS-PdONPs), which prepared by thermal decomposition of Pd(OAc)₂ have high catalytic activity and reusability for several carbon-carbon coupling reactions in water. Linear polystyrene-stabilized Pt nanoparticles (PS-Pt⁽⁰⁾NPs) exhibited high catalytic activity for aerobic alcohol oxidation, hydrogen-transfer reduction, and indole synthesis. The reversible transfer of palladium species between reaction medium (water) and stabilizer (polystyrene) was confirmed for several reactions. For Hiyama coupling reaction, the catalytic activity of PdO nanoparticles (Pd^(II) species) was much higher than that of Pd nanoparticles (Pd⁽⁰⁾ species).

It is a dream for chemists to construct molecular systems, which can transform shape changes of molecules induced by external stimuli, such as chemicals, photons, or electrons (or holes), to macro-scale motion of materials and perform mechanical work. Although elaborate molecular systems, such as molecular shuttles, molecular muscles, molecular elevators, and molecular rotors, have been extensively studied, attempts to link the molecular-scale motion of these man-made devices to macroscopic mechanical work have failed. Any certain methodology how to rationally design the molecular systems to perform macroscopic mechanical work has not yet been developed. In this article we propose to use molecular crystals of diarylethene derivatives for transforming photostimulated shape changes of individual molecules to macro-scale motion of materials. The surface morphology as well as the bulk shape of the single crystals reversibly changes upon photoisomerization of the component diarylethene molecules in the crystals. The crystal shape changes are ascribed to the anisotropic deformation of the crystal lattice induced by the geometrical structure changes of diarylethene molecules upon photoisomerization. The photoinduced crystal deformation performs macroscopic mechanical works, such as launching a silica micro-particle, lifting up a heavy metal ball, and rotating a tiny gearwheel. These results suggest that fabrication of single crystalline assemblies is a promising approach to integrate stimuli-responsive molecules into macroscopic materials that perform significant mechanical work.

Dihalogenation of alkene is well known reaction undergoing in a stereospecific manner. Although enantioselective dihalogenation of alkene using chiral auxiliary was developed, the catalytic protocol remained as a challenging issue. This review summarizes recent progress of catalytic enantioselective dihalogenation of alkene.