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Research Interests

Our major interests are development of novel synthetic organic reactions using characteristics of heteroatoms and/or photochemistry. Since utilization of each element becomes more versatile in recent organic chemistry, development of organic reactions based on these characteristics is one of the important subject in synthetic organic chemistry. Development of efficient organic photoreactions using light as a clean energy source is important in the field of photofunctional materials, synthesis of drugs, and environmentally-friendly chemistry. Our recent research theme are listed below.

Synthesis of novel heterocyclic compounds utilizing dienophilic character of multible bonds containing chalcogen elements

Multiple bonded compounds containing heteroatoms lower than the third periodic law are extremely unstable, so it is often said that the reaction control of them is difficult, conversely, they are highly reactive and are expected to be excellent intermediates in organic reactions. In our laboratory, new reagents have been developed, that are enable to use in conversion of oxygen atoms in carbonyl groups to other calcogen atoms (S, Se, Te) directly to form C=S, C=Se, and C=Te compounds. Moreover, these products show high dienophilic character toward cycloaddition reactions with conjugated dienes, heterodienes, and 1,3-dipoles to give new heterocyclic compounds and biomaterials.

Construction of multi-functionalized molecules using transition-metal catalysts and heteroatoms

Transformation of functional groups using characteristics of various elements in periodic table is more and more required in recent organic chemistry. We are studying about sequential reactions using transition metals such as Zr, Ti, Cu, Zn, Pd, and heteroatoms such as S, Se, and Te, with the aim to develop new synthetic reactions to give highly functionalized compounds from readily available starting materials. So far fields of organometallic chemistry and heteroatom chemistry exist independently, but we would like to connect these two fields, expecting open a new multiple field.

Synthesis of asymmetric ligands having sulfur and selenium

In the field of medicinal chemistry, asymmetric synthesis of organic compounds catalyzed by organometallic complexes is very important. So far many kinds of asymmetric ligands have been developed and high enantiomeric excesses have been obtained. But asymmetric ligands having calcogen atoms such as sulfur and selenium are less known although many unexpected feature may be still remained. In this research, synthesis of bidentate ligands having sulfur and selenium from optically active lactones are continuing.

Development of highly efficient and selective photochemical reactions

Development of photochemical reactions, which are initiated with light as an ecofriendly energy source, is important because they are contrastive to thermal reactions. However, since energy and lifetime of photoexcited molecules are extremely high and short, respectively, compared with ground state molecules, control of them is often difficult to give complex mixtures. Focusing on the structures and reactivities of photoexcited molecules, we are studying development of highly efficient and highly selective photoreactions including elucidation of their reaction mechanisms. Light is a clean energy source, and development of stereoselective photoreactions are important not only for synthetic organic chemistry but also for the medicinal chemistry.

Development of highly emissive organosilicon compounds

With the aim to develop novel fluorescent materials and highly efficient fluorescent probe, photophysical properties of aromatic compounds such as pyrene attaching silyl substituents are studied. Especially, fluorescence quantum yield of pyrene having four trimethylsilylethynyl groups reached to 0.99, meaning that design and synthesis of an extremely emissive organic molecule has been achieved.