Notwithstanding the great potential that inherently chiral, conformationally rigid mediumsized heterocycles hold for drug development, their manufacture is hampered by the intrinsic synthetic challenge that they pose, particularly during the ring-forming step. In addition, achieving configurationally stable products requires the cyclization of precursors with sterically demanding groups, adding to the ring strain of the targets . This strain creates a competition for intermolecular oligomerization, jeopardizing the formation of monomeric cyclized products (Figure , top row). These synthetic challenges are reflected in the great scarcity of synthetic methods for the preparation of these ring systems, and further echoed by the lack of stereocontrolled methods. In fact, existing asymmetric reports focus mostly on the desymmetrization of pre-formed symmetric rings . While we were able to find an excellent report from the Smith group for the asymmetric cyclization of eight-membered rings via an SN2 mechanism , this report delivers products featuring both an inherently chiral ring system and a stereogenic center, as an enantioenriched mixture of diastereomers. Moreover, we found no asymmetric cyclization methodology to prepare inherently chiral seven-membered rings. Our goal in this study became the asymmetric, catalytic cyclization of inherently chiral rings free of other buttressing stereogenic elements. Notably, a superbase iminophosphorane catalyst proved amenable to control both SNAr and SN2 mechanistic paradigms across multiple ring sizes, likely due to its operation on related, key interactions with the same functional groups on different substrates (Figure ).