Chiral Phosphoric Acid Catalyzed Alkylation Reaction Of β-Ketoacids With 3-Hydroxy-3-Substituted Oxindoles

The development of efficient, enantioselective and pratical methods for the construction of C-C and C-heteroatom bonds is highly desirable in modern organic chemistry.In this context, the formation of chiral quaternary carbon stereocenters remains one of the biggest challenges. The 3,3-disubstituted oxindoles bearing a chiral all-carbon quaternary centerare considered as the building blocks for many useful molecules, including pharmaceuticals and natural products. Therefore, the development of new methods for the synthesis of such molecules has become an attractive topic in organic chemistry.In this thesis, we have developed an asymmetric catalytic decarboxylative alkylation reaction of β-ketoacids with 3-hydroxy-3-substituted oxindoles. Under catalysis of chiral phosphoric acids. A series of 3,3-disubstituted oxindoles containing a chiral all-carbon quaternary center were obtained in good to high yields(up to 97%) and enantioselectivities(up to 99%). The important intermediate of(+)–Folicanthine could be achieved from one of the oxindole products.