4-Membered Ring Carbocations: A Positive Development in the Synthesis of 3,3-Disubstituted Oxetanes and Azetidines

4-Membered heterocycles are low molecular weight polar scaffolds with intriguing potential for drug discovery. Despite their unquestionable value, methods to access such heterocycles remain scant. Here, we de-scribe the generation of oxetane-and azetidine-benzylic carbocations as a general strategy to access valuable 3,3-disubstituted derivatives.