Aromatic rings regiospecific functionalization

The ij-arylpalladium bonds in these complexes are reactive and undergo insertion and substitution reactions, and the reactions offer useful methods for the regiospecific functionalization of the aromatic rings, although the reac-... 

The n-arylpalladium bonds in these complexes are reactive and undergo insertion and substitution reactions. The reactions offer useful methods for regiospecific functionalization of aromatic rings, although the reactions are difficult to make catalytic in most cases. Insertion of styrene to AA-dimcthylbcnzylaminc complex (180) to form the stilbene derivative 185 occurs smoothly at room temperature in AcOH [5]. The reaction has been extended to the functionalization of the dopamine analogue (A,A-dimethyl-2-arylethylamine) 187 via the six-membered o/Y/zo-palladated complex 186 [118]. 

Many authors elucidated functionalization of polymers containing reactive oxirane moieties. Epoxidized NR, BR, IR and/or the respective model hydrocarbons, poly (butadiene-co-isoprene, various epoxy resins, poly (2,3-epoxypro-pyl methacrylate) and its copolymers or grafted systems were mostly exploited. Stabilizers based on epoxidized unsaturated rubbers are of the top interest. The mechanism of the functionalization process was studied in details by means of 3,4-epoxy-4-methylheptane and 1,2-epoxy-3-ethyl-2-methylpentane as model compounds [289]. The ring opening of the asymmetric oxirane is regiospecific. Aliphatic primary amines attack the least substituted carbon atom and can be involved in crosslink formation. Aromatic primary and secondary amines are less reactive than aliphatic ones because of their lower basicity the attack on the least substituted carbon atom is however preferred too. 

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