Allene derivatives nucleophilic trapping

As outlined in Sect. B and C, catalytic intermolecular carbopalladations of allenes followed by either /3-hydride elimination or intermolecular nucleophilic trapping provide 1,3-dienes or allyl derivatives bearing the nucleophile moiety, respectively, while an intermolecular carbopalladation followed by intramolecular trapping sequential reaction provides cyclic skeletons (Scheme 27). In Type I, the nucleophilic moiety is connected with the C—X bond, and in lype II it is attached to the allene moiety. 

Besides reacting with nucleophiles, penicillin-derived sulfenic acids are trapped by the electron-poor carbon atom of alkynes, allenes and carbenes [47]. The conjugate addition to alkynes, first explored by Barton et al. [94], generates ene-sulfoxides 152, which can be considered synthetic equivalents of thioesters... 

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