Affiliation:
1. Department of Chemistry Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
2. Department of Chemistry and Research Institute of Basic Science Incheon National University Incheon 22012 Republic of Korea
3. Institute for Convergence Research and Education in Advanced Technology (I-CREATE) Yonsei University Seoul 03722 Republic of Korea
Abstract
AbstractWe describe a catalyst, oxidant, and coupling‐reagent free strategy to access 4‐membered heterocycles, representing a unique example of visible‐light triggered intramolecular cyclization of propargylic alcohols and amines to access oxetanones and azetidinones respectively. Despite the direct 4‐endo‐dig cyclization from these starting materials has proven to be unfavorable, the formation of key p‐quinone methide intermediacy allows an efficient bypass for regioselective 4‐exo‐trig cyclization, resulting in the formation of the desired 4‐membered heterocycles. This mild and operationally simple protocol facilitates the synthesis of products with distinct substitution patterns such as quaternary α‐carbons, and enables late‐stage functionalization.