Limitations. The developed approach towards 2-alkyl azetidines was not without limitations. Our conditions failed to give good yield with (a) intrinsically sterically hindered βsubstituted acrylates (MeCH=CHCO2Me, Me2C=CHCO2Me), (b) non-polarized alkenes (N-Bn maleimide, butadiene sulfone), and (c) electron-rich alkenes (EtOCH=CH2, 2-thiophene-CH=CH2). For a full list of non-reactive alkenes, please, see SI, p 29. The lack of reactivity of the electron-rich alkenes suggests a nucleophilic character of the intermediate N-Boc azetidine radical. Functionalizations. With a practical and scalable protocol toward 2-alkyl azetidines in hand, we converted various products into value-added, multi-functional azetidine-containing building blocks (compounds with one or two functional groups) for use in medicinal chemistry. The standard acidic N-Boc deprotection gave amines "a" (Scheme 4). The structure of amine 22a was proven by X-ray analysis. Reduction of the pyridine/pyrazine ring with H2/Pd in methanol under heating provided diamines "b."