Search

The diastereo‐ and enantioselective construction of vicinal all‐carbon quaternary stereocenters is a formidable task. We here report a synergistic bimetallic catalysis via a chiral N,N′‐dioxide‐europium (Eu) complex and a phosphoramidite‐iridium (Ir) catalyst for the asymmetric allylation of oxindole derivatives by using challenging trisubstituted allylic esters. The allylated products bearing vicinal all‐carbon quaternary stereocenters were obtained with good diastereoselectivities (up to 20 : 1 dr) and excellent enantioselectivities (up to 99 % ee). Control experiments showed that the complementary diastereomers of the products were not accessible by the change of the stereochemistry of the chiral N,N′‐dioxide ligand. [ABSTRACT FROM AUTHOR]

An asymmetric allylic C−H functionalization has been developed by making use of transient chiral nucleophiles, as well as bimetallic synergistic catalysis with an achiral Pd0catalyst and a chiral N,N′‐dioxide‐CoIIcomplex. A variety of β‐ketoesters and N‐Boc oxindoles coupled with allylbenzenes and aliphatic terminal alkenes were well tolerated, furnishing the desired allylic alkylation products in high yields (up to 99 %) with excellent regioselectivities and enantioselectivities (up to 99 % ee). [ABSTRACT FROM AUTHOR]