1,2-Acyl transposition through photochemical skeletal rearrangement of 2,3-dihydrobenzofurans

• 成果类型: Article
• 署名作者: Steele, Ryan T.; Fujiu, Motohiro; Sarpong, Richmond
• 署名单位: University of California System; University of California Berkeley; Shionogi & Company Limited
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10112
• DOI: 10.1126/science.adv9915
• 发表日期: 2025-05-08
• 页码: 631-638
• 关键词: mechanism; isomerization; ACID; photoisomerization; functionalization; stereochemistry; derivatives; constants; methane; state

摘要

Saturated heterocycles are commonly adorned with groups that influence their biological properties. Synthetic methods that transpose existing substituents on saturated heterocycles to multiple peripheral positions are therefore highly valuable. In this work, we report a formal 1,2-acyl transposition through the photochemical exchange of the C2-C3 positions of C2-acylated dihydrobenzofurans. This strategy relies on an unusual photochemical isomerization of the dihydrobenzofuran core to a highly electrophilic spiro-cyclopropane intermediate that is then intercepted by a halide nucleophile. A variety of aryl ketones are transposed using 370-nanometer centered irradiation. Additionally, carboxylic acids, esters, and amides can be transposed using 310-nanometer centered irradiation. This work highlights the power of a skeletal rearrangement to achieve a net peripheral modification.