High molecular weight aromatic polymers by nickel coupling of aryl polychlorides

Abstract

This paper describes a totally new method for the formation of high molecular weight aromatic polymers. High molecular weight polyarylethersulfones are produced by nickel catalyzed coupling of aryl dichloride monomers. Metallic zinc is used to drive the polymerization reaction which takes place under relatively mild conditions in the presence of triphenylphosphine and a dipolar aprotic solvent. The versatility of the reaction is demonstrated, as well as the ability to provide a variety of high temperature polymers from readily available and inexpensive monomers. It is possible to use an integrated two‐step process to produce aryl dichlorides from inexpensive aryl chlorides, and then to couple these directly to polymer without need for isolation and purification. This process resulted from a fundamental understanding of the chemistry and the use of statistically designed experiments to identify the important reaction parameters and to optimize the degree of polymerization.

Synthesis and Ni(0)‐catalyzed polymerization of 2,5‐bis(4‐chloro‐1‐naphthyl)biphenyl

“…4-Chloro-1-naphthaleneboronic acid (3) was synthesized from 4-chloro-1-bromonScheme 2. Ni( 0 ) -catalyzed polymerization of 2,5-aphthalene ( 2 ) by lithiation with n-butyl lithium and bis (4-chloro-1-naphthyl) biphenyl ( 6 ) . subsequent reaction with trimethyl borate.…”

“…The resulting brown suspension was added to a CuCl solution (7.548 g, 76.25 mmol in 40 Scheme 1. Synthesis of 2,5-bis( 4-chloro-1-naphthy1)biphenyl (6) mL of concentrated HC1) which had been prepared and stored in an ice/water bath. Since the mixture became thick and the magnetic stirring was not possible, the mixture was stirred by a glass rod occasionally.…”

“…'*' Additional methods for the synthesis of soluble polyarylenes were reviewed in a previous publication. ' The goal of this communication is to describe the synthesis and polymerization of 2,5-bis( 4-chloro-1-naphthy1)biphenyl ( 6 ) . Poly( 6) (i.e., 7 ) has the same structure as that of the polyarylene containing alternating binaphthylene and biphenylene structural units obtained by cation-radical polymerization of 2,5-bis ( 1-naphthyl) biphenyl, except that the structural units generated by the intramolecular cation-radical cyclization reactions are absent.…”

Synthesis of Aromatic Poly(ether sulfone)s by Nickel-Catalyzed Coupling Polymerization of Aromatic Dichlorides

“…23, No. 4,1991 various substituents have also been prepared. The limitations for the aryl chlorides were described, for example, nitro groups completely inhibited the reaction, and acidic substituents, such as phenolic hydroxyl and carboxylic acids, caused reduction to arene.…”

“…Recently, we showed that nickel-catalyzed coupling polymerization of aryl dichlorides containing ether~ketone structures is a very useful method for the synthesis of aromatic poly( ether ketone )s. 3 In order to expand the preparative utility of this method, it was applied to the synthesis of aromatic poly(ether sulfones)s. Quite recently, the synthesis of aromatic poly(ether sulfone)s by nickelcatalyzed coupling of aryl dichlorides has been reported. 4 This article describes a successful synthesis of aromatic poly(ether sulfone)s by nickelcatalyzed coupling of aromatic dichlorides containing ether sulfone structures.…”