配座制御を設計基盤にしたhemilabile型光学活性配位子の開発と芳香族アルデヒドの不斉アリール化反応への応用　

抄録

Asymmetric arylation of aromatic aldehydes with Rh-our hemilabile-type chiral ligand, (R,R)-4-[bis(3',5'-dimethyl-4'-methoxyphenyl)phosphanomethyl]-5-[bis(3',5'-dimethyl-4'-methoxyphenyl)phosphinomethyl]-2,2-dimethyl-1,3-dioxolane, catalyst is disclosed. Our hemilabile-type ligand was found to display a peculiar catalytic behavior due to the presence of two donors of diverse donating properties. This arylation of various aromatic aldehydes with 2 mol equiv of phenylboronic acid and NaOt-Bu, and a catalytic amount of Rh complex and our hemilabile-type ligand in DME/H₂O (5:1) at 100 °C was performed, obtaining enatioselectivity of up to 84%. This is, to the best of our knowledge, the best enantioselectivity in the reported literature for Rh-catalyzed arylation of aromatic aldehydes.

fig.1