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Some Pentamethylcyclopentadienyl-Ruthenium Derivatives of Methyl Propiolate

DOI

25

Citations

0

References

2000

Year

Michael I. Bruce, Ben C. Hall, Brian W. Skelton, Edward R. T. Tiekink, Allan H. White, N.N. Zaitseva
Australian Journal of Chemistry

Abstract

The reaction between methyl propiolate and RuCl(PPh3)2Cp* and NH4PF6 in EtOH gives cationic vinylidene [Ru{=C=CH(CO2Me)}(PPh3)2Cp*] [PF6] (1), which is deprotonated to Ru(C_CCO2Me)(PPh3)2Cp* by NaOMe. The alkynyl complex reacts with PhCH2Br to give [Ru{=C=C(CH2Ph)(CO2Me)}(PPh3)2Cp*] + , isolated as its bromide and PF6 – salts. In contrast, reactions between methyl propiolate and RuCl(PPh3)2Cp* in benzene afford neutral vinyl-idene RuCl{=C=CH(CO2Me)}(PPh3)Cp* (4) and metallacycle RuCl{CH=C(CO2Me)CH=C(CO2Me)}(PPh3)Cp* (5). The former complex is dehydrochlorinated by NaOMe in the presence of MeCN or P(OMe)3 to give Ru(C_CCO2Me)(L)(PPh3)Cp* [L = MeCN and P(OMe)3, respectively]. A minor product (2%), obtained from treatment of (5) with NaOMe, is Ru{CH=C(CO2Me)CH=C(CO2Me)C=CHC(O)OMe}(CO)(PPh3)2 (8). X-Ray crystal structures of complexes (1), (4), (5) and (8) are reported.