Here we report the first application of a transient directing group in copper enabled C-H functionalization, which is catalytic in amine. This also represents the first C-S bond forming transient C-H functionalization process, enabling the efficient construction of sulfones (Scheme 1c). The aldehyde can be directly used for further derivatisation. Kinetics and deuteration studies have provided insight into the reaction mechanism of this C-H functionalization process.