Catalytic Desymmetrizing Intramolecular Heck Reaction: Evidence for an Unusual Hydroxy‐Directed Migratory Insertion

Mild cationic reaction conditions are used for the efficient desymmetrization of prochiral bishomoallylic alcohols in an intramolecular Heck reaction. This is the first example of a group‐selective Heck cyclization in which the enantiotopic alkene moieties are not incorporated into a cyclic and, therefore, rigid system (see scheme). The high enantioselectivity is attributed to the hydroxy group functioning as a catalyst‐directing group, which could be a novel feature in asymmetric Heck chemistry.