Rearrangement of spirocyclic oxindoles with lithium amide bases.
Spirocyclohexa-2,5-dienes were shown to rearrange at -40 degrees C, when treated with 1 equiv of LDA. Alkyl halides and aldehydes then reacted with the resulting phenanthridinone lithium enolate intermediates, with distinct regioselectivities and high diastereocontrol, to afford functionalized dearomatized phenanthridinones which were elaborated further. A mechanistic scheme involving a diisopropylamine-mediated proton transfer was proposed to rationalize the rearrangement.
Rousseau
Géraldine
G
University Bordeaux 1, Institut des Sciences Moléculaires, UMR-CNRS 5255, 351, cours de la libération, 33405 Talence cedex 05, France.
Robert
Frédéric
F
Schenk
Kurt
K
Landais
Yannick
Y
D000447:Aldehydes / Q000737:chemistry; D000470:Alkaloids / Q000737:chemistry; D000478:Alkylation; D000577:Amides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D031450:Gelsemium / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D000078183:Oxindoles; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D000447:Aldehydes; D000470:Alkaloids; D000577:Amides; D007211:Indoles; D000078183:Oxindoles; D013141:Spiro Compounds; C022960:2-oxindole; D008094:Lithium