Radical cation perchlorates, synthesis

Synthesis of Radical Cation Perchlorates and Subsequent Coupling with NucleophilesT Syntheses of the radical cation perchlorates of BP and 6-methylBP (12) were accomplished by the method reported earlier for the preparation of the perylene radical cation (13,14). More recently we have also synthesized the radical cation perchlorate of 6-fluoroBP (15). Oxidation of the PAH with iodine in benzene in the presence of AgClO. instantaneously produces a black precipitate containing the radical cation perchlorate adsorbed on Agl with... 

The synthesis of the bis-l,3-dithiolium radical cation (TTF+) in 1970 [1] enabled dramatic growth in the field of molecular conductors in the decades thereafter. TTF and several of its homologues are depicted in Scheme 1. The field of low dimensional molecular metals was further motivated by the discovery of the TTF-TCNQ charge-transfer complex in 1973 [2, 3]. Seven years later, superconductivity was induced in the cation-radical salt, (TMTSF)2PF6, upon application of 12 kbar pressure [4]. Shortly thereafter, superconductivity below 1.4 K was observed at ambient pressure in the perchlorate analog [5]. 

Likewise, benzyldihydroisoquinolinium derivatives can be used in a photochemical synthesis of tetrahydroisoquinolines. Thus, 2-(2-trimethyl-silylmethylphenylmethyl)-3,4-dihydroisoquinoliniun perchlorates have been successfully cyclized, as in the synthesis of the protoberbine alkaloids (+)xylopinine and (+)stylopine. The reaction proceeds via SET from the xylyl donor to the iminium moiety, fragmentation of the benzylsilane radical cation and carbon-carbon bond formation in the intermediate diradical. The synthesis is rather general and the yields compare favorably with those obtained from related substrates via a dipolar cycloaddition methodology [298] (Sch. 27). 

Nucleophiles, when they are used in the presence of cupric perchlorate, capture the cation-radicals initially formed. Instead of benzidines, the para-substituted dialkylanilines were obtained. In this a manner, A,A-dialkylanilines with halo or thiocyanato moieties in para positions were prepared in good yields under the same (simple) conditions. Scheme 7.13 illustrates the sequence of the transformations observed. The products are useful intermediates in the synthesis of dyes, drugs, and color cinema formulations. 

The ABA-type block copolymers B-86 to B-88 were synthesized via termination of telechelic living poly-(THF) with sodium 2-bromoisopropionate followed by the copper-catalyzed radical polymerizations.387 A similar method has also been utilized for the synthesis of 4-arm star block polymers (arm B-82), where the transformation is done with /3-bromoacyl chloride and the hydroxyl terminal of poly(THF).388 The BAB-type block copolymers where polystyrene is the midsegment were prepared by copper-catalyzed radical polymerization of styrene from bifunctional initiators, followed by the transformation of the halogen terminal into a cationic species with silver perchlorate the resulting cation was for living cationic polymerization of THF.389 A similar transformation with Ph2I+PF6- was carried out for halogen-capped polystyrene and poly(/>methoxystyrene), and the resultant cationic species subsequently initiated cationic polymerization of cyclohexene oxide to produce... 

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