Development of Catalyst Technology for Producing Methyl Methacrylate (MMA) by Direct Methyl Esterification

The direct methyl esterification reaction for MMA was commercialized. Precisely synthesized Pd₃Pb₁ catalyst and the catalysis at the proposed reductive oxidation reaction condition (PROC) realized and guaranteed high MMA yield and long catalyst life. Controlled Pd distribution in a catalyst particle drastically decreased Pd loss from the catalyst during reaction. Unit processes are introduced as well.     

Efficient and diversity-oriented total synthesis of Riccardin C and application to develop novel macrolactam derivatives

Riccardin C (RC, 1) is a macrocyclic bis(bibenzyl) natural product exhibiting remarkable biological activity as a nuclear liver X receptors (LXRs) ligand and a lipid metabolism mediator. RC is expected to be a lead compound to develop drugs for atherosclerotic diseases, and therefore exploiting diversity-oriented synthesis of RC is a promising approach to drug discovery. In this paper, we report novel total synthesis of RC (7.4% overall yield in 16 steps) by using the intramolecular S_NAr reaction as key cyclization reaction. This is the first example of efficient macrocyclization using 3-nitro-4-fluorostilbene as an electrophile. The methodology could be applied to synthesize novel lactam analogs of RC. The diversity-oriented synthesis of RC is versatile method for the synthesis of various types of bis(bibenzyl) natural products and their derivatization.     

Redox Properties of CeO2 at Low Temperature: The Direct Synthesis of Imines from Alcohol and Amine

We disclosed the redox properties of CeO₂ in organic reactions at low temperature of 303 K. CeO₂ works as the most effective heterogeneous catalyst for imine formation from benzyl alcohol and aniline at 303 K among various metal oxides and showed more than 38‐fold higher activity than other simple metal oxides. CeO₂ is applicable to the reaction of various alcohols and amines and gives high yields (80–98 %) and high selectivities (89–>99 %). Kinetic measurements, MS, and FTIR analyses demonstrated that the high activity of CeO₂ is a result of reactive oxygen species at the redox sites on CeO₂. This discovery can help to create a new field in metal oxide catalysis.     

Annulenediones having quinonoid properties

Chemical and Electrochemical reductions of bisdehydro[14]- and [18]annu1ened1ones clearly revealed their quinonoid nature.