A Concise Preparation of Yuehchukene and Its Analogues

Synthesis and Functionalization of Indoles Through Palladium-catalyzed Reactions

“…An adequate set of conditions was developed to allow for the isolation of indol-2-yl allenyl ketone intermediates. With aryl halides and vinyl halides and triflates,217a carbonylative cross-coupling of triethyl( N -methylindol-2-yl)borate produced N -methylindol-2-yl ketones (Scheme ). Variable amounts of cross-coupling products not incorporating carbon monoxide and N -methyl-2-ethylindole were also isolated.…”

Highly Diastereoselective [3+2] Cyclopenta[b]annulation of Indoles with2‐Arylcyclopropyl Ketones and Diesters

“…[7] Another class of naturally occurring cyclopenta [b]indole alkaloids are represented by kopsane, [8] possessing an architecturally beautiful tetracyclic propellane type annulated indole substructure exhibiting cholinergic activity. [9,10] Several syntheses of yuechukene [11][12][13] and cyclopenta [b]indole frameworks have been reported in the literature. [14][15][16][17][18][19] Kerr and co-workers recently described an elegant approach for cyclopenta [b]indoles by reaction of 1,3-dimethylindoles with 1,1-cyclopropane diesters in the presence of ytterbium trifluoromethanesulfonate.…”

3,3-Dimethyl-1,2,3,4-tetrahydrocyclopenta[b]indole-1,2-dione (bruceolline E)

“…tionality using selenium dioxide (Gribble et al, 1988) in 60% yield. Similar Nazarov cyclizations with indoles (Bergman & Venemalm, 1992;Cheng & Cheung, 1996;Ishikura et al, 2000;Miki et al, 2001;Churruca et al, 2010) have been reported.…”

“…For examples of similar tandem acylation/Nazarov cyclization with pyrroles, see: Song et al (2006). For examples of Nazarov cyclizations with indoles, see: Bergman & Venemalm (1992); Cheng & Cheung (1996); Ishikura et al (2000); Miki et al (2001); Churruca et al (2010). For examples of -diketone oxidations using selenium dioxide, see: Gribble et al (1988); Xu et al (2002); Belsey et al (2006).…”