Synthesis of Arenetricarbonylmanganese Cations and Hydrogen Migrations in the Cyclohexadienyltricarbonylmanaganese Series

Improvements in the preparation of some arenetricarbonylmanganese cations and the preparation of (1,4‐dimethoxybenzene)tricarbonylmanganese hexafluorophosphate are described. Substitution of hydrocarbon groups into these complexes is possible via the known exo‐addition of organolithium reagents followed by thermal hydrogen‐shift and then hydride abstraction. The rearrangement is shown to involve migration of the 6‐endo hydrogen probably via a metal‐hydride intermediate.