Tricarbonyl-chromium complexes of benzannelated cycloproparenes

Reaction of 1H-cyclopropa b]naphthalene ( 1a ) or 1H-cyclopropab]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.