Our optimized biphasic protocol (1 equiv. Bu4NOH, CF3-toluene/H2O, 23 °C) worked well with a range of sulfamate and sulfamide epoxide substrates (Scheme 4). In general, substrates cyclize cleanly and without observable side products. The mass balance of the reactions is good and is generally comprised of product and small amounts of unreacted starting material. Several functional groups are compatible with the reaction conditions, including aryl halides (Scheme 4, Entries 1 and 8), aryl ethers (Scheme 4, Entry 1), benzyl ethers (Scheme 4, Entry 2), and pendant sulfamates (Scheme 4, Entry 3). Both trans and cis sulfamate epoxides (Scheme 4, Entry 5) cyclized efficiently. While 6-membered rings were preferred in most cases, through judicious choice of the epoxide, 5membered heterocycles could be forced to form (Scheme 4, Entry 6). Products 13 (CCDC: 2231586), 27 (CCDC: 2231587), and 31 (CCDC: 2231588) were crystalline solids, and their x-ray structures have allowed us to confidently assign product identity and relative stereochemistry (See Supporting Information for full crystallographic details and additional structural proof).