  Herein, intervalley scattering is exploited to account for anomalous
antiresonances in the infrared spectra of doped and disordered single layer
graphene. We present infrared spectroscopy measurements of graphene grafted
with iodophenyl moieties in both reflection microscopy and transmission
configurations. Asymmetric transparency windows at energies corresponding to
phonon modes near the {\Gamma} and K points are observed, in contrast to the
featureless spectrum of pristine graphene. These asymmetric antiresonances are
demonstrated to vary as a function of the chemical potential. We propose a
model which involves coherent intraband scattering with defects and phonons,
thus relaxing the optical selection rule forbidding access to ${\bf q} \neq$
{\Gamma} phonons. This interpretation of the new phenomenon is supported by our
numerical simulations that reproduce the experimental features.
