Strategies were sought to effect cyclizations of oligo (m-phenylene ethynylene) by exploiting pseudo-high dilution effects on polymer supports. Using Pd/Cu-catalyzed coupling protocols, Merrifield's resin (1% crosslinked chloromethylated polystyrene) proved inadequate for site isolation; inter-site couplings ensued on the flexible support. Conversely, use of the Argopore resin, a more highly crosslinked polystyrene, inhibited inter-site ...
