The design of etheric and thioetheric building blocks for polymer synthesis

A new approach to the design of monomeric and oligomeric ether and thioethers is presented in this article. Nucleophilic aromatic substitution (SNAr) of cyclopentadienyliron complexes of chloroarenes with a number of aliphatic and aromatic dihydroxy or disulfide nucleophiles, led to the formation of the diiron complexes (2a-g) in very good yields. Some of these sulfur complexes were further oxidized to produce the sulfone complexes (4a-c). Functionalization of the diiron complexes with terminal chloro groups (2a, 2c and 4a) was also achieved using S,Ar reactions. The cyclopentadienyliron moieties were removed easily by photolytic demetallation to give the free monomeric and oligomeric ether, thioether and sulfone compounds in yields ranging from 70 to 93%.