Catalytic asymmetric fragmentation of cyclopropanes

• 成果类型: Article
• 署名作者: Raut, Ravindra Krushnaji; Matsutani, Satoshi; Shi, Fuxing; Kataoka, Shuta; Poje, Margareta; Mitschke, Benjamin; Maeda, Satoshi; Tsuji, Nobuya; List, Benjamin
• 署名单位: Hokkaido University; Hokkaido University; Max Planck Society; Hokkaido University; Hokkaido University; National Institute for Materials Science
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8523
• DOI: 10.1126/science.adp9061
• 发表日期: 2024-10-01
• 页码: 225-230
• 关键词: bronsted acid; noncovalent interactions; density functionals; activation; isomerization; strain; desymmetrization; Visualization; CHALLENGES; mechanism

摘要

The stereoselective activation of alkanes constitutes a long-standing and grand challenge for chemistry. Although metal-containing enzymes oxidize alkanes with remarkable ease and selectivity, chemical approaches have largely been limited to transition metal-based catalytic carbon-hydrogen functionalizations. Alkanes can be protonated to form pentacoordinated carbonium ions and fragmented into smaller hydrocarbons in the presence of strong Br & oslash;nsted acids. However, catalytic stereocontrol over such reactions has not previously been accomplished. We show here that strong and confined acids catalyze highly enantioselective fragmentations of a variety of cyclopropanes into the corresponding alkenes, expanding the boundaries of catalytic selective alkane activation. Computational studies suggest the involvement of the long-debated cycloproponium ions.