Metal catalysis versus organocatalysis in the catalytic asymmetric synthesis of 3-hydroxyoxindole

3-Substituted 3-hydroxyoxindoles are widely encountered in a large number of natural products, drugs and pharmaceutically active compounds. The catalytic asymmetric construction of this privileged skeleton has attracted great attention from synthetic chemistry, and much progress has been made in recent years. This review summarizes the advances in the catalytic enantioselective synthesis of four important types of subunits of 3-substituted 3-hydroxyoxindoles, and focuses on the discussion of the differences and advantages of metal catalysis and organocatalysis.