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Metal Carbene Dimerization: Versatile Approach to Polyalkynylethenes


  • This research was supported by the MEC, Spain (CTQ2004-08077 and CTQ2007-61048; fellowships to D.S. and A.G.) and the Principado de Asturias (GE-EXP01-11). We are grateful to Dr. A. Soldevilla (Universidad de La Rioja) for his assistance in the X-ray crystallographic analysis.


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Heads or tails? Chemo-, regio-, and stereoselective access to cross- and linear conjugated poly-ynene scaffolds from alkynyl-derived group six metal carbenes is reported. The metal carbenes shown (M=Cr, W; TIPS=triisopropylsilyl) readily undergo low-temperature, tail-to-tail dimerization in the presence of potassium tert-butoxide by reaction at either of the Cβ atoms to provide E-polyalkynylethenes.