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The reaction of the diferrocenylphosphenium ion with four terminal allenes follows two different pathways, via allyl or vinyl carbocations, which proceed with electrophilic substitution reactions at one ferrocenyl moiety to form persistent Wheland intermediates and eventually alkenyldiferrocenylphosphonium salts. The reaction of the diferrocenylphosphenium ion with 2‐(trimethylsilyl)‐2,3‐pentadiene affords a stable Wheland intermediate of ferrocene in high yields, which is isolated and fully characterized. A kinetically stable Wheland intermediate of the electrophilic aromatic substitution at ferrocene is isolated from the reaction of the diferrocenylphosphenium ion with the allene 2‐(trimethylsilyl)‐2,3‐pentadiene and fully characterized.

The Front Cover shows a round‐bottomed flask containing a burgundy solution of diferrocenylphosphenium ion [Fc2P][B(C6F5)4], which was used in this work to activate various allenes. Dropwise addition to 2‐(trimethylsilyl) penta‐2,3‐diene yields a bright red solution of a stable Wheland intermediate of ferrocene, whose solid‐state structure is depicted as a ball‐and‐stick model. In front lies Saint Peter’s Key, a prominent feature of the City of Bremen’s coat of arms, representing the unlocked potential of highly reactive main group species. More information can be found in the Research Article by E. Hupf, J. Beckmann and co‐workers (DOI: 10.1002/ceur.202500031).