Covalent Folding of Fluorinated Polyphenylene by Sulfur Fluorine Annulative Substitution.

We report that fluorinated polyphenylene P50 undergoes folding-like sulfur fluorine annulative substitution (SFAS) to form a well-defined tubular helix H50. This is achieved with atomic precision in an exceptionally efficient manner, involving the simultaneous transformation of 98 C-F bonds with the yield per reaction site approaching 99.9 %.