Catalytic Asymmetric Allylic Substitution/Isomerization with Central Chirality Transposition.

We have developed a catalytic asymmetric allylic substitution/isomerization process with central chirality transposition. This process takes advantage of the ambident reactivity of the 2-indole imine methide generated in situ from racemic tertiary indolylmethanols. The use of a suitable chiral phosphoric acid catalyst and an ortho -directing group allowed regioselective formation a C-C bond at the 3 position but enantiocontrolled construction of a stereogenic center at the 2-benzylic position.