In summary, we have demonstrated an efficient stereoselective C(3) mono-cis functionalization of piperidines and tetrahydropyran bearing a C(4) aminoquinoline directing group. As key features, lower reaction temperatures (45-50 °C) were employed, ensuring high stereocontrol, whilst the use of MesCOOH additive achieved high levels of starting material conversion of up to 95%. A DoE study generated reaction conditions that minimized the competing diarylation and epimerization processes resulting in high stereoselectivity and an overall reduction in the amounts of reagents used. Additionally, single mono-trans diastereomers could be directly accessed through a one-pot arylation-epimerization protocol.