Synthesis and Applications of Tricarbonyliron Complexes of Dendralenes

[3]Dendralene and [4]dendralene are converted smoothly into tricarbonyliron complexes. The structures of four complexes analyzed by DFT and single‐crystal X‐ray analysis show that, in contrast to free hydrocarbons, complexed dendralenes prefer a roughly in‐plane conformation. The complexes are stable towards Fe(CO) 3 group migration up to 150 °C. The synthetic value of Fe(CO) 3 complexation in the dendralene series is demonstrated through a variety of selective synthetic manipulations (Diels–Alder reaction, dipolar cycloaddition , Simmons–Smith cyclopropanation , dihydroxylation, olefin cross metathesis ) that are not achievable by direct transformation of the free hydrocarbons. Application to the synthesis of a previously unreported, highly reactive linear/cross‐conjugated hydrocarbon is also described.