Abstract
Furanocoumarins are attractive targets in the synthetic organic and medicinal chemistry field because of their structural diversity and interesting biological properties. Herein, we describe the synthesis of furanocoumarin natural products from common furanocoumarin skeletons. A key step was a novel intramolecular radical cyclization onto nitrile to synthesize angular and linear franocoumarins, which was optimized by reacting iodocoumarin derivatives in the presence of (Me3Si)3SiH and oxygen. These compounds served as intermediates in the syntheses of vaginidiol, vaginidin, oroselol, multivittan D, gaudichaudine, oreoselone, peucedanin, and smyrindiol, successfully demonstrating the versatility of the intermediates and utility of the radical cyclization method for accessing furanocoumarin natural products.
Chemical and Pharmaceutical Bulletin 71(8) 624-632 2023年8月1日
To develop dearomatization reactions based on a nucleophilic activation of phenols, naphthols, and indoles, ipso-Friedel–Crafts-type C-alkylation must be selectively promoted over competitive O- or N-alkylation reactions. Resolving this chemoselectivity issue is essential for developing this class dearomatization reaction. We found that various dearomatization reactions could be developed using appropriately designed aromatic substrates with an electrophilic moiety for intramolecular reactions. This review describes the transition-metal-catalyzed dearomatization reactions developed by our group. π-Allylpalladium species, η3-propargylpalladium species, alkynes activated by Au(I) species, and silver carbene species could be applied as electrophiles in our reaction system, which provided access to a wide variety of dearomatized products from planar aromatic compounds in a highly chemoselective manner.
This paper presents the advances in the synthesis of dragmacidin E. Since its isolation from a southern Australian deep-water marine sponge by Capon et al. in 1998, the Funk, Feldman, Jia, and Nemoto groups have conducted synthetic studies on this bis-indole alkaloid. An overview of the synthetic studies reported thus far, including the total synthesis of (±)-dragmacidin E achieved by Feldman et al. in 2011, is presented.