509085-87-4Relevant academic research and scientific papers
Ring opening of a cobalt-stabilized bornyl cation: Mechanistic study of the alkyne-dicobalt/carbynyl-tricobalt cluster transformation
Kaldis, John H.,Morawietz, Peter,McGlinchey, Michael J.
, p. 1293 - 1301 (2003)
Upon protonation with HBF4, [2-endo-((allyldimethylsilyl)ethynyl)borneol]Co2(CO)6 (2) suffers elimination of water or propene, to yield [2-((allyldimethylsilyl)ethynyl)born-2-ene]-Co2(CO)6 (11) and [2-endo-((dimethylfluorosilyl)ethynyl)borneol]Co2(CO)6) (12), respectively, and, surprisingly, the tricobalt complex (2-norbornylidene)CHCCo3(CO)9 (13). In contrast, protonation of the terminal alkyne (2-endo-ethynylborneol)Co2(CO)6 (19), an anticipated precursor to 13, led instead to (2-ethynyl-2-bornene)Co2(CO)6 (21) and the ring-opened species (2-ethynyl-4-isopropyl-1-methylcyclohexa-1,3-diene)Co2 (CO)6 (22). However, conversion of 19 to 13 was achievable upon prolonged heating at reflux in acetone, thereby also affording the corresponding alcohol [2-(2-hydroxybornyl)]CH2CCo3(CO)9 (20). A mechanistic rationale is offered for the formation of RCH2CCo3(CO)9 clusters upon protonation of alkyne complexes of the type (RC≡CH)Co2(CO)6.
