Diastereoselective cycloadditions and transformations of N-alkyl and N-aryl maleimides with chiral 9-anthrylethanol derivatives.
Thermal Diels-Alder reactions of chiral 9-methoxyethyl and 9-hydroxyethyl anthracene have been investigated both experimentally and computationally with a range of N-substituted maleimides. Whereas cycloadditions with 9-methoxyethyl anthracene proceeded with almost complete diastereselectivity, those with 1-anthracene-9-yl-ethanol resulted in essentially no diastereoselectivity. Subsequent regio- and stereoselective transformations with reducing agents and carbon nucleophiles demonstrated the synthetic utility of this methodology, which was applied to the enantioselective synthesis of pyrrolo[2,1-a]isoquinolines and an attempted synthesis of the alkaloid crispine A. Computational studies supported the proposed hypotheses for the stereoselectivity observed in the transformations described.
Adams
Harry
H
Department of Chemistry, Dainton Building, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
Elsunaki
Tareg M
TM
Ojea-Jiménez
Isaac
I
Jones
Simon
S
Meijer
Anthony J H M
AJ
D000873:Anthracenes / Q000737:chemistry*; D003500:Cyclization; D000431:Ethanol / Q000031:analogs & derivatives / Q000737:chemistry*; D007546:Isoquinolines / Q000138:chemical synthesis* / Q000737:chemistry; D008301:Maleimides / Q000737:chemistry*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D013237:Stereoisomerism
D000873:Anthracenes; D007546:Isoquinolines; D008301:Maleimides; C523713:crispine A; D000431:Ethanol