Photocatalyzed Cascade Reactions of Cyclopropanols and α‐Trifluoromethyl‐Substituted Olefins for the Synthesis of Fused gem‐Difluorooxetanes

• Published in: Angewandte Chemie Vol. 134; no. 44
• Main Authors: Zhang, Yunxiao, Niu, Yunhong, Guo, Youyuan, Wang, Jiaxin, Zhang, Yizhi, Liu, Shanshan, Shen, Xiao
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 02.11.2022
• Subjects: Alkenes; Cascade chemical reactions; Catalysis; Chemistry; Cyclopropanols; Energy transfer; Energy Transfer Photocatalysis; Homogeneous Catalysis; Photoredox catalysis; Reaction Mechanisms; Substitutes; Substrates; Synthetic Methods
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202212201

Fluorinated fused rings are challenging to construct from simple starting materials. Herein, we report the first photocatalyzed cascade reactions of readily available cyclopropanols and α‐trifluoromethyl‐substituted olefins for the synthesis of fused gem‐difluorooxetanes. Two rings and three bonds were efficiently constructed in one reaction. The reaction showed broad substrate scope and the downstream transformations of the products demonstrated the synthetic potential of the reaction. The mechanistic study supported the presence of cascade photoredox catalysis and energy transfer catalysis/direct photo‐excitation processes. A combination of photoredox catalysis and energy transfer catalysis/direct photo‐excitation enables cascade reactions of cyclopropanols and α‐CF3‐olefins, in which two rings and three bonds are constructed in one reaction, affording fused gem‐difluorooxetanes. The reaction shows broad substrate scope, complete cis‐selectivity, and downstream transformations of the products demonstrated the synthetic potential.