The　properties　of　poly(vinyl　ether)s　(PVEs)　are　highly　dependent　on　their　tacticity,　and　the　appealing　thermoplastics　features　of　isotactic　PVEs　have　drawn　considerable　efforts　to　develop　stereoselective　cationic　polymerization　methods　to　access　this　class　of　polymers.　However,　reported　methods　that　could　achieve　a　high　degree　of　tacticity　control　are　limited　to　process　employing　metal-based　Lewis　acids,　and　with　various　limitations　on　catalyst　loading,　monomer　scope,　etc.　Here,　we　introduce　a　metal-free　stereoselective　cationic　polymerization　of　vinyl　ethers　by　employing　a　class　of　chiral　confined　Brønsted　acids,　imidodiphosphorimidates　(IDPis),　as　the　catalyst.　This　organocatalytic　approach　features　its　metal　free　conditions,　high　efficiency,　high　stereoselectivity,　single　catalyst　system,　operation　simplicity,　etc.[Figure　not　available:　see　fulltext.]　©　2021,　Science　China　Press　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.