Grubb

Internationally renowned authors, among them K. C. Nicolaou, H. Iwamura, R. H. Grubbs and H. Hopf, present the full potential of acetylene chemistry, from organic synthesis through materials science to bioorganic chemistry. 

Grubbs, R., Risse, W. and Novae, B. The Development of Well-defined Catalysts for Ring-Opening Olefin Metathesis. Vol. 102, pp. 47-72. 

Grubbs and Brunck (86) have recently reported experimental evidence supporting this mechanism. They have made an attempt to synthesize the proposed metallocyclic intermediate for the metathesis of ethene. Starting from the assumption that a mixture of WC1 and two equivalents of (C4H9)Li forms an active metathesis catalyst (49), they treated WC1 with 1,4-dilithio-2,3-dideuterobutane. One may expect that the following reaction would take place ... 

Grubbs and Brunck found that ethene was formed and that this product consisted of 88% C2H3D, 6% C2H4, and 6% symmetric C2H2D2. They also demonstrated that C2H4 and C2H2D2 were not formed by a secondary reaction. From this they inferred that a migration of 12% of the metal atoms had taken place. 

It can be concluded from the study of Grubbs and Brunck that indeed a metal-carbon cr-complex might be the key intermediate in the metathesis reaction. For the conversion of I into II several reaction pathways can be... 

Dlugosz J, Fraser GV, Grubb D, Keller A, Odell JA, Goggin PL (1976) Polymer 17 471... 

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