Direct arylation polymerization

Rudenko, A.E., Thompson, B.G., 2015. Optimization of direct arylation polymerization (DArP) through the identification and control of defects in polymer structure. J Polym. Sci. Part A -Polym. Chem. 53, 135-147. 

Scheme 9 Example of direct arylation polymerization (DARP) [54]...

This strategy, known as direct arylation polymerization (DARP), can be used for the synthesis of several organic systems and with a large variety of catalysts and co-catalysts [57-59]. Various mechanisms have been proposed, depending on the catalytic system employed however, the metaUation at the non-halogenated position of the monomer is believed to be concerted and base assisted [60]. 

Rudenko AE, Wiley CA, Stone SM, Tannaci IF, Thompson BC (2012) Semi-random P3HT analogs via direct arylation polymerization. J Polym Sci A Polym Chem 50 3691-3697... 

Electron-deficient thiophene-based monomers including thieno[3,4-c] pyrrole-4,6-dione (TPD), furo[3,4-c]pyrrole-4,6-dione (FPD) monomers, diketopyrrolopyrrole and isoindigo can be copolymerized with bromi-nated thiophene-based electron-rich monomers such as benzodithiophene, dithienosilole, and dithienogermole by direct arylation polymerization. Additionally, electron deficient 4,4 -dinonyl-2,2 -bithiazole and 1,2,4,5-tetra-fluorobenzene are highly reactive toward direct arylation polymerization. ... 

Mentioned below are broadly eleven ways of synthesizing these polymers Method A Electrochemical Polymerization Method B Solution Polymerization Method C In situ Chemical Oxidative Polymerization Method D Dispersion Polymerization Method E Vapor-Phase Polymerization Method F SoUd-State Polymerization Method G Solvent-Free Chemical Polymerization Method H Grignard Metathesis (GRIM) Polymerization Method I Direct C-H Arylation Polymerization Method J Stille Polymerization Method K Yamamoto Polymerization... 

New Development Direct Arylation and Chain-Growth Polymerization... 

Direct (hetero)arylation polymerization is a methodology that can be added to a polymer chemists toolbox. This reaction may be applied to the preparation of novel polymers synthesized from copolymers that are unstable as or-ganometallic reagents. It can provide a more facile entry into known polymers if the monomers can be selectively activated, however careful optimization and control is required. 

Scheme 4 Direct (hetero)arylation polymerization (DHAP) [99] and polymerization by C-S bond cleavage [100]...

As noted in the previous section, aryl free radicals and cation-radicals are the primary products of the photolysis of diaryliodonium and triarylsulfonium salts. The aryho-dinium and diarylsulfmium cation-radicals are, therefore, the species ultimately responsible for initiating cationic polymerization. Undoubtedly, these cation-radicals are capable of directly initiating polymerization. Indeed, the stable and much less reactive aminium perylene cation-radicals have received considerable... 

Polymers containing arylamide units have been prepared by forming the amide bonds directly during polymerization or by using monomers that contain amide units and linking them, e.g. by nucleophilic substitution, to form poly(arylether amide)s. for example, Baek and Harris [119] prepared two self-polymerizable AB2 amide monomers, namely W,W -bis(4-fluorobenzoyl)-3,4-diamino-4 -hydroxydi-phenylether (Table 2, entry 1) and W,W -bis(4-fluorobenzoyl)-3,5-diamino-4 -hydroxybenzophenone (Table 2, entry 2), and polymerized them to afford a hb poly(aryl ether amide) and a hb poly (aryl ether ketone amide). The aryl fluoride-... 

Routes to prepare substituted polymer directly were pioneered with the polymerization of /V-trimethy1si1y1phosphoranamines to form low to moderate molecular weight polyphosphazenes (6) where R is alkyl or aryl (8). 

The direct preparation of arylboronic esters from aryl halides or triflates now allows a one-pot, two-step procedure for the synthesis of unsymmetrical biaryls (Scheme 1-41) [147]. The synthesis of biaryls is readily carried out in the same flask when the first coupling of the triflate with diboron 82 is followed by the next reaction with another triflate. The synthesis of naturally occurring biflavanoids and the couphng of N-(phenylfluorenyl)amino carbonyl compounds to polymeric supports are reported [154]. 

The quinone methide can also be generated in situ, at least in aqueous NaOH, directly from the peracetate, as hydrolysis of the phenolic acetate is faster than the benzylic acetate (see an example in Section 12.5.3). This method was used to demonstrate the addition of anthrahydroquinone (AHQ) and anthranol to (actual polymeric) lignin quinone methides in studies elucidating the anthraquinone (AQ)-catalyzed 8-0-4-aryl ether cleavage mechanisms in alkaline pulping.64-66... 

A superior and relatively versatile procedure for the synthesis of unsymmetrical dialkyl thioethers, which avoids the unattractive direct use of thiols, utilizes the stable l-alkylthioethaniminium halides, which are readily obtained from thioacet-amidc [32] (Scheme 4.4). The reaction has also been used for the synthesis of alkyl aryl thioethers from activated aryl halides [33], but it cannot be used for the synthesis of cyclic thioethers, as polymeric sulphides are formed from a,co-dihaloalkanes. A similar sequence to that which leads to the thioethers has been used for the synthesis of S-alkyl thioesters [34] (see 4.1.26). 

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