Enantioselective total syntheses of welwitindolinone A and fischerindoles I and G.
The first total syntheses of welwitindolinone A and the most complex members of the fischerindole family, fischerindoles I and G, are reported. Highlights of these short, protecting-group-free syntheses include the application of the recently developed direct indole-carbonyl coupling, a simple approach for installing the quaternary center with neighboring chlorine atom, a regioselective dehydrogenation/dehydration cascade to access fischerindole I, and a remarkably facile oxidative ring contraction to construct welwitindolinone A. An alternative biogenetic hypothesis, whose accuracy is suggested by the success of the current syntheses, is also put forth for this alkaloid family.
Baran
Phil S
PS
Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA. pbaran@scripps.edu
Richter
Jeremy M
JM
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D000458:Cyanobacteria / Q000737:chemistry; D026121:Indole Alkaloids; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009570:Nitriles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000470:Alkaloids; D026121:Indole Alkaloids; D007211:Indoles; D009570:Nitriles; C491991:fischerindole; C507638:welwitindolinone A