Thiophenyl zinc

The palladium-catalyzed cross-coupling of thiophenyl zinc reagents with aromatic dihalides was recently described (eq 5) [9]. The method was published in communication form but it did appear this could be a generally useful polymerization technique. 

Varying ratios of the ligands 7V-(2-thiophenyl)-2,5-dimethylpyrrole and V-methylimidazole were used to form tetrahedral zinc complexes with S4, S3N, and S2N2 coordination spheres. X-ray structural analyses and IR spectra were recorded for all compounds and the relevance to zinc finger proteins was discussed. The comparison to cobalt and cadmium structures showed only minor differences, supporting the theory that changes on substituting these metals into zinc proteins would be minor.538... 

In 2007, a photoresponsive molecular tweezer, zinc porphyrin-dithienylethene-zinc porphyrin (ZnP-DTE-ZnP) triad was reported by Park and Shin (Scheme 4) [32], The main synthesis procedure was the Wittig reaction between 5-(4-bromo-methylphenyl)-10,15,20-tris (4-methylphenyl)-porphyrin and l,2-di(2-methyl-4-formyl-3-thiophenyl) perfluorocyclopentene. 

Yamamoto has synthesized a variety of zinc porphyrin-containing polymers (29-35) with arylene and aryleneethynylene linkers.42 Arylene groups incorporated included 2,5,-dialkoxy-1,4-phenylene, 3-alkyl-2,5-thiophenyl, and 2-alkyl-3,6-pyridenyl species. Due to their long substituents, these polymers are soluble in THF and have molecular weights of 4600-38,000 Da (A/n, GPC). Powder X-ray diffraction revealed some degree of order in the thin films prepared from polymers with long alkyl substituents. Photoluminescence, thermal analysis, and CV of the new polymers were also reported. 

Other means of forming biaryl derivatives include the use of zinc/silver-graphite reaction with aryl and heteroaryl (including thiophenyl) iodides... 

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