Yang Liangkun, Li Shiyang, Ning Lichao, Zhao Hansen, Zhou Liang, Cao Weidi, Feng Xiaoming
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, China.
Nat Commun. 2024 Dec 30;15(1):10866. doi: 10.1038/s41467-024-55110-3.
The activation of C-C bond of benzocyclobutenones under mild reaction conditions remains a challenge. We herein report a photoinduced catalyst-free regio-specific C1-C8 bond cleavage of benzocyclobutenones, enabling the generation of versatile ortho-quinoid ketene methides for aza-[4 + 2]-cycloaddition with imines, which offers a facile route to isoquinolinone derivatives, including seven family members of protoberberine alkaloids, gusanlung A, B, D, 8-oxotetrahydroplamatine, tetrahydrothalifendine, tetrahydropalmatine, and xylopinine. Furthermore, the catalytic enantioselective version of this strategy is also realized by merging synergistic photocatalysis and chiral Lewis acid catalysis. Mechanistic studies provide compelling evidence to rationalize the photoisomerization/cycloaddition cascade process.
在温和反应条件下实现苯并环丁烯酮C-C键的活化仍然是一项挑战。我们在此报告了一种光诱导的、无催化剂的苯并环丁烯酮区域特异性C1-C8键裂解反应，该反应能够生成通用的邻醌型乙烯酮甲基化物，用于与亚胺进行氮杂-[4+2]-环加成反应，为异喹啉酮衍生物的合成提供了一条简便途径，其中包括原小檗碱类生物碱的七个家族成员：古山龙A、B、D、8-氧代四氢巴马汀、四氢thalifendine、四氢巴马汀和木番荔枝碱。此外，通过协同光催化和手性路易斯酸催化相结合，还实现了该策略的催化对映选择性反应。机理研究提供了令人信服的证据，以合理化光异构化/环加成串联过程。
