Migratory insertion, acylpalladium derivatives

Inversion of configuration observed with allyl and benzyl derivatives has been deduced from the results sununarized in Scheme 4. In the case of allyl derivatives, a very reasonable and seemingly unmistakable assumption that nucleophilic attack on 7r-allyl ligands takes place on the side opposite to Pd was made. On the other hand, an equally plausible assumption that migratory CO insertion and methanolysis of acylpalladium derivatives both proceed with retention. ... 

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