Enantioselective 1,3-dipolar cycloadditions of diazoacetates with electron-deficient olefins.
[reaction: see text] A general strategy for highly enantioselective 1,3-dipolar cycloaddition of diazoesters to beta-substituted, alpha-substituted, and alpha,beta-disubstituted alpha,beta-unsaturated pyrazolidinone imides is described. Cycloadditions utilizing less reactive alpha,beta-disubstituted dipolarophiles require elevated reaction temperatures, but still provide the corresponding pyrazolines with excellent enantioselectivities. Finally, an efficient synthesis of (-)-manzacidin A employing this cycloaddition methodology as a key step is illustrated.
Sibi
Mukund P
MP
Department of Chemistry, North Dakota State University, Fargo, North Dakota 58105, USA. mukund.sibi@ndsu.edu
Stanley
Levi M
LM
Soeta
Takahiro
T
D000085:Acetates / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D003500:Cyclization; D004583:Electrons; D007094:Imides / Q000737:chemistry; D015394:Molecular Structure; D011743:Pyrimidines / Q000138:chemical synthesis / Q000737:chemistry; D011758:Pyrroles / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
D000085:Acetates; D000475:Alkenes; D001391:Azo Compounds; D007094:Imides; D011743:Pyrimidines; D011758:Pyrroles; C470325:manzacidin A