Metallation of bicymantrenyl and synthesis of polycymantrenyls

Article abstract of DOI:10.1016/S0022-328X(96)06556-4

Bicymantrenyl, η⁵,η⁵-C₁₀H₈[Mn(CO)₃]₂ (1), may be metallated at the Cp-ring with BuLi (THF, -60°C) to give monolithium (2) and polylithium derivatives. Metallation of 1 proceeds concurrently on both α-and β-positions, the β-substitution product being predominant. A number of derivatives of 1 with substituents R = D, COOH, CHO, PPh₂ have been synthesized in the reactions of monolithium derivative 2 with different electrophiles (D₂O, CO₂, DMFA, Ph₂PCl respectively). Under the action of CuCl₂ the oxidative coupling of 2 proceeds to give tetracymantrenyl (11a). Oxidative coupling of a mixture of 2 with cymantrenyllithium affords two isomers of tricymantrenyl (12a, 12b). The structures of 11a, 12a, 12b were established by an X-ray study.