Polycondensation via Carbenoid Coupling Reactions of

3 Polycondensation via Carbenoid Coupling Reactions of Bis(dichloromethyl)arenes 

In connection with nickel-catalysed reductive coupling reactions of dihaloarenes, leading to poly(arylene)s, the copper-catalysed reductive carbenoid coupling reactions involving substituted bis(dichloromethyl)arenes and metals or other reductants should be mentioned. The reductive carbenoid coupling of bis(phenyldichloromethyl)arene with zinc in the presence of Cu-based catalysts is shown below  

In this case, the respective substituted poly(arylene vinylene) is formed [159-161], 

Palladium- or nickel-catalysed carbonylation polycondensation of dibromoar-enes with bifunctional nucleophilic monomers such as aromatic diamines and bisphenols in the presence of carbon monoxide appeared to be a new promising method for the synthesis of aromatic polyamides [scheme (15)] and polyesters [scheme (16)] respectively [162-170], The first successful example was the synthesis of high molecular weight polyaramide according to scheme (15) (Ar1 = m-C6H4-, Ar2 = p-C6H4 O C6H4 ) [162], 

The general catalytic cycle for this carbonylation coupling reaction is analogous to direct carbon-heteroatom coupling [scheme (39)] except that carbon monoxide insertion takes place after the oxidative addition step and prior to the nucleophilic attack of the amine [scheme (40)]  

---