Synthesis and Utilization of Functionalized Polystyrene Resins

Significance

The authors have developed an operationally simple, reliable, and cost-effective method of derivatizing 4-bromopolystyrene 1 to generate a range of functionalized resins. Thus, the treatment of 1 with Oshima’s trialkylmagnesate complex i-Pr(n-Bu)₂MgLi gave Grignard-like polymer 2 quantitatively, which was then intercepted with chlorodiphenylphosphine to form polymer-supported triphenylphosphine 3. Polymer 3 could be used as a polymer-supported reagent and a scavenger. For example, the reaction of 4-bromobenzoic acid with 4-penten-1-ol was performed in the presence of DBAD and 3 in THF at 0 °C under nitrogen to produce ester 4 in good yield. Unreacted DBAD was scavenged by adding more triphenylphosphine resin 3 at the end of the reaction.