Tricarbonyl‐chromium complexes of benzannelated cycloproparenes

Abstract Reaction of 1 H ‐cyclopropa [ b ]naphthalene ( 1a ) or 1 H ‐cyclopropa[ b ]anthracene ( 10a ) with tris(acetonitrile)tricarbonylchromium affords cyclobutanaphthalenone and cyclobutaanthracenone 2 and 11 , respectively. In contrast, the bis‐silylated Cycloproparenes 1b and 10b undergo complexation at the terminal benzene ring and lead to the arene‐tricarbonylchromium complexes 4b and 12 , respectively. Desifylation of 4b to 4a is effected by t ‐BuOK.