Catalytic Enantioselective Synthesis of N–C Axially Chiral Mebroqualone and Its Derivatives through Reductive Asymmetric Desymmetrization

In the presence of (<i>R</i>)-DTBM-SEGPHOS-Pd­(OAc)₂ catalyst, treatment of various 3-(2,6-dibromophenyl)­quinazolin-4-ones with NaBH₄ gave optically active N–C axially chiral quinazolinone (mebroqualone) derivatives through reductive asymmetric desymmetrization (enantioselective monohydrodebromination) followed by kinetic resolution of the resulting monobromophenyl products (up to 99% ee). The enantioselectivity strongly depended on the substituent (R²) at the C4′position, amount of NaBH₄, and reaction temperature