Synthesis and structure of allenyl-substituted η6-benzene(tricarbonyl)chromium complexes

Article abstract of DOI:10.1002/cber.19971300816

The Cr(CO)₃-complexed η⁶-phenylpropargylic alcohols 3 react in a displacement rearrangement with thionyl chloride or chlorodiphenylphosphane to give the chloro- or phosphorylallenyl substituted η⁶-phenyl complexes 4 and 6, respectively. In the X-ray crystal structure of the novel organometallic allenic derivatives 4b and 6b the vicinal chloro or phosphoryl substituent and the benzene(tricarbonyl)chromium fragment are arranged coplanarily. Palladium/copper-catalyzed couplings of the chloroallene 4b with terminal alkynes disclose a facile access to ynallene derivatives 8, novel carbon-rich organometallic π-systems. Keywords: Arene complexes / Chromium / Allenes / Rearrangements VCH Verlagsgesellschaft mbH.