Organometalic chemistry is one of the fundamental research area with great potential; Innumerable combinations of elements and bonding modes are possible, and therefore, it still has a lot of room which has been still unexplored. In addition, development of organometalic chemistry enables to synthesize new compounds, which can lead to development of vairous fields including molecular catalysts, functional materials, polymer synthesis, and pharmaceuticals. Our research project is based on organic synthesis, but our goal is "innovative discovery" which would stimulate the related sciences.

1. Synthetic Transformations Exploiting Light as the Energy Source
 Photosynthesis produces carbohydrates starting from CO2 and H2O by exploiting solar light as the energy source. This intriguing synthetic system, if liberally interpreted, consists of two stages. One is "light reaction", a photo-induced reaction producing energetic compounds. Another is "dark reaction", a thermal reaction of the resulting energetic compounds. We are engaged in the development of new synthetic transformations of unreactive materials like CO2 based on this two-stage mechanism.

2. Synthetic Transformations Based on Cleavage of Unreactive Bonds
  Reactivities of organic molecules generally originate from their π-bonds like C=C and C=O, polar σ-bonds like C–Br and C–Li, and non-bonding electron pairs. Non-polar σ-bonds like C–H and C–C are far less reactive, and thus remain intact under conventional reaction conditions in most cases. Therefore, if such non-polar σ-bonds are site-selectively cleaved and are utilized for construction of carbon skeletons, it would create unconventional opportunities of enormous synthetic potential. We have tackled to this challenging issue and found that transition metals like nickel and rhodium promote C-C cleavage reactions of cyclobutanones. In recent years, we have tried to exploit light as the driving force to induce even energetically uphill transformations, which are intrinsically difficult only by thermal reactions.

3. Multiple Functionailzation of Terminal Alkynes in One-pot
 Terminal Alkynes are readily available. In addition, they possess reasonable reactivity as well as stability. Consequently, terminal alkynes serve as useful starting substances for organic synthesis. We are engaged in the development of multiple functionalization of terminal alkynes to produce complex molecules in a single flask. For example, we have developed synthetic methods for N-heterocyclic compounds through denitrogenative transformations of triazoles robustly generated by the (3+2) cycloaddition reaction of terminal alkynes with azides (Huisgen reaction).


1. 光エネルギーを利用する有機合成

2. 不活性結合の切断に基づく有機合成

3. 末端アルキンを出発原料に利用するワンポット多官能基化