Nucleophilic substitution heteroatomic nucleophiles, allylic derivatives

Another type of substitution reaction is increasing in popularity—the use of an allylic substrate, such as an allyl acetate where the nucleophile is introduced with stereochemical control in the presence of a palladium catalyst and a chiral ligand. Reactions where a chiral anion, be it derived from a chiral heteroatom group, such as a sulfoxide, or an auxiliary, such as Evans s oxazolidinones, are not included in this chapter because the alkyl halide is usually relatively simple and the stereochemical selectivity is derived from the system itself. 

Allylic aeetates or carbonates can undergo nucleophilic substitutions via palla-dium(0)-catalysis (11). In this paper, we report on the extension of this reaction to unsaturated fatty aeids by the preparation of allyl carbonates and acetates of oleic, linoleic, and 10-undecenoic acid and their substitution with carbon- and heteroatom-nucleophiles by palladium(0)-catalysis. In this way, different substituents can be in-trodueed into the alkyl chain of fatty acids. This leads to fatty acid derivatives in which the properties of biologically active compounds may possibly be combined with the amphiphilic property of the fatty acid. 

Catalytic reactions of allylic electrophiles with carbon or heteroatom nucleophiles to form the products of formal S 2 or S 2 substitutions (Equation 20.1) are called "catalytic allylic substitution reactions." Tliese reactions have become classic processes catalyzed by transition metal complexes and are often conducted in an asymmetric fashion. The aUylic electrophile is typically an allylic chloride, acetate, carbonate, or other t)q e of ester derived from an allylic alcohol. The nucleophile is most commonly a so-called soft nucleophile, such as the anion of a p-dicarbonyl compound, or it is a heteroatom nucleophile, such as an amine or the anion of an imide. The reactions with carbon nucleophiles are often called allylic alkylations. 

Use of Alkenes as Precursors to 7T-Allylpalladium Derivatives in Allylic Substitution with O, N, and Other Heteroatom Nucleophiles... 

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