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Syntheses and reactivity of neutral iron and ruthenium vinylidene complexes

Stephen J. Walters, Harry Adams, Neil A. Bailey, Peter R.G.A. Salmon, Claire Sumner, and Mark J. Winter

Department of Chemistry, The University, Sheffield S3 7HF, UK.

Abstract

The anions [M(SnPh₃)(CO)(COCH₂R)(h-C₅H₅)]^- (M = Fe, Ru; R = H, Me, and Ph) react with MeCOCl to give acyl(oxy) carbenes M(SnPh₃)(CO){=C(OCOMe)CH₂R}(h-C₅H₅). These eliminate MeCO₂H resulting in the neutral iron and ruthenium half-sandwich vinylidene complexes M(SnPh₃)(CO)(=C=CHR)(h-C₅H₅). Deprotonation of these with LiBuⁿ affords reactive anionic h¹-alkynyl complexes [M(SnPh₃)(CO)(CCR¹)(h-C₅H₅)]^- which in turn react with electrophiles to afford new neutral vinylidene complexes M(SnPh₃)(CO)(=C=CR¹R²)(h-C₅H₅).

Summary

We present here syntheses and a few preliminary reactions of some neutral half-sandwich vinylidene complexes of iron and ruthenium. The results are reinforced by X-ray crystallographic data. These compounds are unusual since most vinylidene complexes are cationic and our neutral complexes therefore offer interesting synthetic possibilities.

Index

• Synthesis of M(SnPh₃)(CO)(=C=CHR)(h-C₅H₅)
  • Solid state structure of Fe(SnPh₃)(CO)(=C=CHPh)(h-C₅H₅)
• Reactions of M(SnPh₃)(CO)(=C=CHR)(h-C₅H₅)
  • Solid state structure of Fe(SnPh₃)(CO)(=C=CMe₂)(h-C₅H₅)
• Comparison of Fe(SnPh₃)(CO)(=C=CMe₂)(h-C₅H₅) with Fe(COMe)(CO)(PPh₃)(h-C₅H₅)
  • Solid state structure of Fe(COMe)(CO)(PPh₃)(h-C₅H₅)
• Conclusions