Wang Shuzhong, Zheng Nuowen, Deji Cuo, Hu Qingzhong, Wu Xinxin, Zhan Ruoting, Huang Huicai, Zhang Yue
Key Laboratory of Chinese Medicinal Resource from Lingnan, Ministry of Education, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510006, People's Republic of China.
Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren-Ai Road, Suzhou, Jiangsu 215123, China.
Org Lett. 2024 Jun 7;26(22):4705-4710. doi: 10.1021/acs.orglett.4c01470. Epub 2024 May 23.
Herein, visible-light-promoted [4π + 2σ] annulation of dienes and alkylamines was achieved via dual C(sp)-H bond functionalization of alkylamines. The elusive enamine precursors are generated under mild conditions by photoredox catalysis, efficiently annulated by the diene, and simultaneously functionalized with two aliphatic C(sp)-H bonds, resulting in the productive synthesis of new aromatic rings. The aromatic ring construction provides direct access to 2-hydroxybenzophenone derivatives in high yields (up to 90%). This [4π + 2σ] annulation reaction demonstrates mild reaction conditions, high reaction efficiency, and broad functional group tolerance, and this synthetic protocol has been made available for the late-stage transformation of natural products and commercial drugs.
在此,通过烷基胺的双C(sp)-H键官能团化实现了可见光促进的二烯与烷基胺的[4π + 2σ]环化反应。难以捉摸的烯胺前体在温和条件下通过光氧化还原催化生成,能被二烯有效环化,并同时用两个脂肪族C(sp)-H键进行官能团化,从而高效合成新的芳环。芳环构建可直接高产率(高达90%)地得到2-羟基二苯甲酮衍生物。这种[4π + 2σ]环化反应展现出温和的反应条件、高反应效率以及广泛的官能团耐受性,并且该合成方案已可用于天然产物和商业药物的后期转化。