RESUMO
Chiral C2-symmetric 3,3'-bis((R,R)-2-naphthylethylaminomethyl)-(R)-binaphthol (AMB4) functions as an efficient organocatalyst for the asymmetric epoxidation of various alkylidenemalononitriles. The spiro-epoxyoxindole products obtained from isatilidenemalononitriles were easily transformed to the corresponding chiral dihydroquinoxalinyl spirooxindoles.
RESUMO
A phosphoiminoBINOL ligand was designed to form a dinuclear metal complex that could hold a malononitrile molecule. The dinuclear bis(phosphoimino)binaphthoxy-Pd2(OAc)2 complex catalyzed a double Mannich reaction of N-Boc-imines with malononitrile to give chiral 1,3-diamines with high enantioselectivity. The rational asymmetric catalyst, which smoothly introduces the first coupling product to the second coupling reaction while avoiding the reverse reaction, facilitates the over-reaction into a productive reaction process.