General and Practical Metal-Free Aziridination and Cyclopropanation of XH2 (X = N, C) with Alkenes by Thianthrenation

Three-membered cyclic structures are widely existing in natural products and serve as enabling intermediates in organic synthesis. However, the efficient and straightforward access to such structures with diversity remains a formidable challenge. Herein, a general and practical protocol to aziridines and cyclopropanes synthesis using free XH2 (X = C or N) with alkenes by thianthrenation is presented. This metal-free protocol features the direct aziridination and cyclopropanation of unprotected NH2 under mild conditions. Free sulfonamides, amides, carbamates, amines, and methylene with acidic protons, are good precursors for three-membered ring formation, providing an attractive alternative for straightforward synthesis of aziridines and cyclopropanes from easily available starting materials.