The kinetics of diffusion-controlled reaction of an end-functionalized polymer chain with a fixed random array of reactive "trap" sites is examined as a function of trap concentration n. It is demonstrated that a frequency-dependent trapping rate coefficient is generally required to describe the trapping dynamics. Scaling methods and renormalized perturbation theory are used to examine the behavior of this rate coefficient as a function of nR(3) and dimensionless frequency s tau, where R is the radius of gyration and tau is the terminal relaxation time of the polymer. The Rouse model is employed throughout, although extensions to account for hydrodynamic interactions and entanglements are straightforward. The implications of our results for reactive blending and polymer adsorption processes are discussed.