Modular enantioselective photocatalysts from privileged pybox scaffolds

• 成果类型: Article
• 署名作者: Kelch, Riley M.; Hammerling, Lea; Zysman-Colman, Eli; Yoon, Tehshik P.
• 署名单位: University of Wisconsin System; University of Wisconsin Madison; University of St Andrews
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aeb5832
• 发表日期: 2026-04-09
• 页码: 188-193
• 关键词: acid; photoredox; ligands; photochemistry; CYCLOADDITION; ion

摘要

Modern organic synthesis relies upon the availability of chiral catalysts to control the stereochemistry of bond-forming reactions. Several families of chiral catalysts have become recognized as privileged structures because of their notable generality for diverse transformations with different reaction mechanisms. However, examples of highly enantioselective photocatalyst structures remain scarce. We have designed a family of enantioselective photocatalysts by modifying the structures of privileged pyridine bis(oxazoline) complexes with electron-donating carbazole units. The chiral ligands are accessible through a three-step synthetic sequence starting from commercially available chiral pool materials, and their charge-transfer photochemistry can be rationally tuned to optimize photocatalytic activity. We demonstrate the generality of these new chiral photocatalyst structures in a series of three model asymmetric reactions, which includes both photoredox and excited-state photoreactions.