Asymmetric synthesis using organic catalysts (N-oxide, phosphine oxide, etc.)
Although the progress of catalytic reactions in recent years has been remarkable, most of the catalysts used in organic chemistry are composed of metals and ligands. High-yielding precious metals and heavy metals that are difficult to dispose of are often used in these catalysts. In addition, due to the low stability of the complex, strict reaction conditions are required, and in most cases, the ligand and metal must be recovered separately after the reaction. Therefore, a reaction catalyzed by a pure organic compound that does not use any metal has appeared. Of course, since it does not use metal, it is more advantageous than metal catalytic reaction in terms of environmental friendliness, and it also has the advantage that the catalyst is stable in water and air and easy to handle.
By the way, N-oxide and phosphine oxide are unique functional groups with high electron donating ability. Despite being extremely old compounds, there have been few examples of using them in synthetic organic chemistry as catalysts.
We have found that our proprietary axial asymmetric N-oxides and phosphine oxides BINAPO are effective as catalysts or ligands in some asymmetric reactions. These reactions are the first successful examples of asymmetric reactions using organic oxide compounds, and we believe that they have opened up new possibilities for organic oxide compounds in synthetic organic chemistry.