Li Hongji, Subbotina Elena, Bunrit Anon, Wang Feng, Samec Joseph S M
State Key Laboratory of Catalysis (SKLC) , Dalian National Laboratory for Clean Energy (DNL) , Dalian Institute of Chemical Physics (DICP) , Dalian 116023 , China . Email:
University of Chinese Academy of Sciences , Beijing 100049 , China.
Chem Sci. 2019 Feb 19;10(12):3681-3686. doi: 10.1039/c8sc05476b. eCollection 2019 Mar 28.
The idea of using biaryl structures to generate synthetic building blocks such as spirolactones is attractive because biaryl structures are abundant in biomass waste streams. However, the inertness of aromatic rings of biaryls makes it challenging to transform them into functionalized structures. In this work, we developed photoinduced dearomatization of nonphenolic biaryl compounds to generate spirolactones. We demonstrate that dearomatization can be performed either aerobic photocatalysis or anaerobic photooxidation to tolerate specific synthetic conditions. In both pathways, dearomatization is induced by electrophilic attack of the carboxyl radical. The resulting spirodiene radical is captured by either oxygen or water in aerobic and anaerobic systems, respectively, to generate the spirodienone. These methods represent novel routes to synthesize spirolactones from the biaryl motif.
利用联芳基结构生成诸如螺内酯之类的合成砌块的想法很有吸引力，因为联芳基结构在生物质废物流中大量存在。然而，联芳基芳香环的惰性使得将它们转化为功能化结构具有挑战性。在这项工作中，我们开发了非酚类联芳基化合物的光致脱芳构化反应以生成螺内酯。我们证明脱芳构化反应可以通过有氧光催化或厌氧光氧化来进行，以适应特定的合成条件。在这两种途径中，脱芳构化反应都是由羧基自由基的亲电攻击引发的。在有氧和厌氧体系中，生成的螺二烯自由基分别被氧气或水捕获，以生成螺二烯酮。这些方法代表了从联芳基基序合成螺内酯的新途径。
