Catalytic Enantioselective Synthesis of a 3-Aryl-3-benzyloxindole (=3-Aryl-3-benzyl-1,3-dihydro-2H-indol-2-one) Exhibiting Antitumor Activity

A palladium-catalyzed intramolecular a-arylation of an amide in the presence of a bulky chiral N-heterocyclic carbene ligand is the key step in the first catalytic synthesis of (3R)-6-chloro-3-(3-chlorobenzyl)-1,3-dihydro-3-(3-methoxyphenyl)-2H-indol-2-one ((R)-5). This oxindole, in racemic form, had been shown previously to be an anticancer agent. (R)-5 was obtained with an overall yield of 45% and with 96% enantioselectivity.