Total synthesis of justicidin B, justicidin E, and taiwanin C: A general and flexible approach toward the synthesis of natural arylnaphthalene lactone lignans

Kai Wei; Yucui Sun; Yiren Xu; Wen Hu; Ying Ma; Yi Lu; Wen Chen; Hongbin Zhang

doi:10.3389/fchem.2022.1103554

Total synthesis of justicidin B, justicidin E, and taiwanin C: A general and flexible approach toward the synthesis of natural arylnaphthalene lactone lignans

Front Chem. 2022 Dec 22:10:1103554. doi: 10.3389/fchem.2022.1103554. eCollection 2022.

Authors

Kai Wei^{1

2}, Yucui Sun¹, Yiren Xu¹, Wen Hu¹, Ying Ma¹, Yi Lu¹, Wen Chen¹, Hongbin Zhang¹

Affiliations

¹ Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research and Development of Natural Products, Yunnan Characteristic Plant Extraction Laboratory, School of Pharmacy, Yunnan University, Kunming, China.
² Henan Engineering Research Center of Funiu Mountain's Medical Resources Utilization and Molecular Medicine, School of Medical Sciences, Pingdingshan University, Pingdingshan, China.

Abstract

Lignans are widely present in traditional medicinal plants. Many natural arylnaphthalene lactone lignans (NALLs) isolated from the genera Justicia, Haplophyllum, and Phyllanthus possess interesting biological activities. Herein, we report a general strategy for the total synthesis of this kind of lignans. Features of this new approach are an aryl-alkyl Suzuki cross-coupling to introduce the dioxinone unit, a cation-induced cyclization to construct the aryl dihydronaphthalene, and base-mediated oxidative aromatization to furnish the arylnaphthalene core. By incorporating these key transformations, the total syntheses of justicidins B and E and taiwanin C covered type I and type II NALLs were accomplished.

Keywords: Suzuki cross-coupling; arylnaphthalene lactone lignans; cation-induced cyclization; natural products; total synthesis.