Total Synthesis of the Flavonoid Natural Product Houttuynoid A

Abstract

The first total synthesis of the antiviral flavonoid houttuynoid A (1) has been achieved from aryl ketone 6 and benzofuran aldehyde 5 in nine linear steps. The C-C-C structure of the flavonoid was synthesized by an I-catalyzed oxa-Michael addition of a chalcone intermediate, generated by the Claisen-Schmidt condensation of 5 and 6. This work provides a method for the synthesis of houttuynoids and provides a reference for the synthesis of the remaining members of the houttuynoid family.

Unraveling Plant Natural Chemical Diversity for Drug Discovery Purposes

“…Arboridinine Kopsia arborea (plant) 5 1 6 2 3 1 6 adunctin B (Dethe and Dherange, 2018) Piper adunctum (plant) 4 1 8 1 3 6 2 3 (±)-deguelin Tephrosia vogelii (plant) 5 1 9 3 2 4 6 2 englerin A (Hatakeyama, 2018) Phyllanthus engleri (plant) 5 1 9 2 6 2 3 1 3 houttuynoid A (Jian et al, 2018) Houttuynia cordata (plant) 5 2 2 3 4 7 2 4 (−)-mucosin (Nolsoe et al, 2018) Reniera mucosa ( This kind of tool would incredibly ease the access to plant natural chemical diversity and should ideally be comprehensive, organized and include data from worldwide plant species, from past to recent studies. Such a globalized database could furthermore be integrated to other ones like genomic, phylogenic, species occurrence, biosynthetic pathway, biological activity, or chemical classification (Allen et al, 2019) allowing researchers to mine the resources and correlate the information, hence empowering all kind of research studies.…”

Synthesis of 2-Substituted Benzo[b]furans/furo-Pyridines Catalyzed by NiCl2

“…At first, a series of nickel salts were screened and NiCl 2 was found to be the best, affording the most results and the corresponding product 3a in an 80% yield (Table 1, entry 1). Various bases were screened to identify the optimized condition where weak and organic bases such as KHCO 3 and Et 3 N (triethylamine) were found to be unsuitable for this transformation ( Table 1, entries [10][11][16][17]. However, a strong base like NaOH could promote this cyclization to give the title product with the yield of 80% ( Table 1, entry 1).…”

“…2-substituted benzo[b]furans/furo-pyridines are important building blocks in biologically active compounds such as anti-inflammation agents and anti-fungal activities (Scheme 1) [1][2][3][4][5][6]. Due to these excellent properties, the synthesis of these skeletons has become a hot spot in recent years [7,8].…”

Maternal intelligence quotient and motor development in early childhood: The mediating role of mother's education

“…Maternal IQ was assessed by well‐trained researchers using the short form of WAIS‐RC, which had good reliability and validity in China (the test–retest reliability was 0.89) . The WAIS‐RC assessed verbal and performance abilities, including four subtests: similarities, information comprehension, picture completion and block design.…”