Intermediate complexity models, carbon cycle

The catalytic cycle in Scheme 21 is adapted from that proposed by Jolly et al. " for the dimerization of 1,3-butadiene with intermolecular trapping as discussed above. In the model the bisdiene coordinates around a reduced palladium center (e.g., 66) and undergoes oxidative addition with cyclization (oxidative coupling) via the yyn-addition of carbon and palladium across the diene to afford the intermediate palladacycle 68. Protonation of the Tj -allyl in an Se2 fashion leads to the aUcene complex 69, and stereospecific anfi-addition... 

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