  We review the potentialities offered by the study of backward exclusive
processes in a new scaling regime, i.e. involving a large -timelike or
spacelike- Q2 photon and a baryonic exchange in the t-channel. We recall the
concept of Transition Distribution Amplitudes (TDAs) containing unique
information on the hadron structure, then discuss how they enter the
description of processes such as backward electroproduction of a pion,
antiproton-proton annihilations into a dilepton + meson as well as into J/psi +
meson. We then discuss first phenomenological studies for processes that are
being analysed at JLAB and HERMES or that will be measured by Panda at
GSI-FAIR. Finally we present outlooks for their theoretical studies based on
approaches such as the pion-cloud model.
