Construction of an ortho-phenol polymer

Article abstract of DOI:10.1016/S0040-4039(01)01256-4

Synthesis and study of an ortho-phenol polymer, a highly functionalized polyphenylene, have been conducted. A dibromo ortho-biphenol monomer was synthesized and its homocoupling in the presence of Ni(1,5-cyclooctadiene)₂ followed by hydrolysis led to the formation of an ortho-phenol polymer. This polymer was soluble in common organic solvents. It was characterized by gel permeation chromatography, UV-vis, IR, ¹H and ¹³C NMR spectroscopic methods. The use of this polymer in the Lewis acid-catalyzed reaction of phenylacetylene with benzaldehyde in the presence of diethylzinc was studied. It was found that the polymer when treated with 1/4 equiv. (relative to the phenol unit of the polymer) of Ti(OⁱPr)₄ generated a much more active Lewis acid catalyst than when treated with excess Ti(OⁱPr)₄. This indicates that different types of catalytic sites in the polymer have been produced under these conditions.