Nucleophiles chelated diene complexes

S.2. rj n-Alkyl Complexes by Nucleophilic Attack on Metal-Chelating Diene Complexes. 

Nucleophiles reactions with alkene complexes S.8.2.3.4 chelated diene complexes 5.S.2.5.2... 

Both 1,4- and 1,5-dienes form stable complexes with Pd. For most 1,3-dienes, such as 1,3-butadiene, reaction with Pd° compounds leads to 7r-allyl formation. These reactions are described in Section 7. The coordinated double bonds in palladium diene complexes are reactive toward attack by many nucleophiles, and the resulting chelating alkene palladium alkyls are easily isolated. Many useful reactions of dienes were discovered by Jiro Tsuji in the 1960s and 1970s. These have been recently reviewed in a historical memoir. ... 

Many nncleophiles add to one of the double bonds of chelating palladium(diene) complexes to give a chelating Pd alkyl(alkene) derivative, as exemphfied by the reaction of PdCl2(l,5-cod) with methoxide (equation 41). In most cases, the direction of attack is exo. If the nucleophile is in a form that can undergo transmetalation with the Pd l bond, such as Ph2Hg, the nucleophihc group can be delivered endo. In this case, prior formation of a Pd nucleophile bond accounts for the direction of attack (equation 42). 

Dehydrogenation of alkanes 5.8.2.2.1 Diene complexes chelated reaction with nucleophiles 5.8.2.5.2 chelating... 

As mentioned above nonconjugated dienes give stable complexes where the two double bonds can form a chelate complex. A common pathway in palladium-catalyzed oxidation of nonconjugated dienes is that, after a first nucleophilic addition to one of the double bonds, the second double bond inserts into the palladium-carbon bond. The new (cr-alkyl)palladium complex produced can then undergo a /(-elimination or an oxidative cleavage reaction (Scheme 2). An early example of this type of reaction, although not catalytic, was reported by Tsuji and Takahashi (equation 2)12. 

---