Lignans comprise a family of secondary metabolites existing widely in plants and also in human food sources. As important components, these compounds play remarkable roles in plants’ ecological functions as protection against herbivores and microorganisms. Meanwhile, foods rich in lignans have revealed potential to decrease of risk of cancers. To date, a number of promising bioactivities have been found for lignan natural products and their unnatural analogues, including antibacterial, antiviral, antitumor, antiplatelet, phosphodiesterase inhibition, 5-lipoxygenase inhibition, HIV reverse transcription inhibition, cytotoxic activities, antioxidant activities, immunosuppressive activities and antiasthmatic activities. Therefore, the synthesis of this family and also their analogues have attracted widespread interest from the synthetic organic chemistry community. Herein, we outline advances in the synthesis of lignan natural products in the last decade.

A new and general method to functionalize the C(sp 3 )−C(sp 2 ) bond of alkyl and alkene linkages has been developed, leading to the dealkenylative generation of carbon-centered radicals that can be intercepted to undergo Ni-catalyzed C(sp 3 )−C(sp 2 ) cross-coupling. This one-pot protocol leverages the easily procured alkene feedstocks for organic synthesis with excellent functional group compatibility without the need for a photoredox catalyst.

An efficient and scalable total synthesis of (−)-triptonide is accomplished based on a metal-catalyzed hydrogen atom transfer (MHAT)-initiated radical cyclization. During the optimization of the key step, we discovered that blue LEDs significantly promoted the efficiency of reaction initiated by Co­(TPP)-catalyzed MHAT. Further exploration and optimization of this catalytic system led to development of a dehydrogenative MHAT-initiated Giese reaction.