274689-85-9Relevant academic research and scientific papers
Reactions of cyclopropenone derivatives with a cyclopentadienylcobalt(I) chelate: Formation of a cobaltacyclobutenone and a transformation of 2,2-dimethoxycyclopropenone to methyl acrylate at cobalt
Foerstner, Jan,Kakoschke, Alf,Wartchow, Rudolf,Butensch?n, Holger
, p. 2108 - 2113 (2000)
Reactions of cyclopropenone derivatives with the [2-(di-tert-butylphosphanyl)ethyl]cyclopentadienylcobalt(I) chelate system were investigated. Ethene complex 2 reacts with diphenylcyclopropenone under cobalt insertion to give cobaltacyclobutenone chelate complex 6 in 91% yield. 6 was characterized crystallographically and shows a structure similar to that of a known platinacyclobutenone. Thermoanalysis of 6 indicated a reaction at elevated temperature, which was shown to be a cycloreversion at 60°C leading to known diphenylethyne and carbonyl complexes 7 and 9. Attempts to reduce the metallacyclobutenone with lithium tetrahydridoaluminate resulted in the cycloreversion reaction at a temperature as low as -100 to -90°C, the lithium cation acting as a Lewis acid. The reaction of dimethoxycyclopropene complex 4 with zinc triflate unexpectedly resulted in the formation of methyl acrylate complex 13, which was characterized crystallographically.
