Effect of polymer architecture on the efficiency of acyl transfer reactions

A series of spacer-modified polystyrene-supported hydroxamic esters and hydroxamic dithiocarbonic anhydrides were prepared starting from divinyl benzene and ethyleneglycol dimethacrylate crosslinked polystyrene resins through multistage polymer-analogous reactions. Acyl transfer reactions using these polymer-supported hydroxamic acylating agents containing spacer arms of various lengths were carried out. The investigation revealed a sharp increase in reactivity as the length of the spacer arm was increased from zero methylene spacer to five methylene spacers. Investigations were also carried out to correlate the extent of acyl transfer with the nature and degree of crosslinking and the relative polarity of the polymer network. It was found that the extent of functionalization in each of the polymer analogous reactions and the extent of acylation reaction decreased with an increase in the degree of crosslinking. (C) 1996 John Wiley & Sons, Inc.