“…Heterogeneous acidic catalysts that have been successfully employed for this purpose include sulfonated polymers (Amberlyst‐15 and Nafion‐H), neutral alumina, mesoporous aluminosilicate, organotin phosphate condensates (OPCs), and Fe 3+ ‐montmorillonite, but it is unlikely that they could achieve sufficient interaction with the pendant functionalities of polymers to efficiently promote functionalization. Soluble compounds or complexes of main group metals, transition metals, and lanthanides are well‐known for their Lewis acidity and have been investigated specifically for their ability to catalyze the alcoholysis of epoxides. The catalytic activities of non‐metallic Lewis acids like BF 3 , CBr 4 , hydrazine sulphate, molecular iodine, iminium triflate, and trimethylsilyl triflate, as well as compounds able to participate in single‐electron reactions like 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone, tetracyanoethylene, ceric ammonium nitrate, N ‐methylpyrrolidine‐2‐one hydrotribromide, and 1‐benzyl‐2,4,6‐triphenylpyridinium tetrafluoroborate, have also been explored.…”