Catalytic enantioselective pyrrole alkylations of alpha,beta-unsaturated 2-acyl imidazoles.
[reaction: see text] Enantioselective additions of pyrroles to alpha,beta-unsaturated 2-acyl imidazoles catalyzed by the bis(oxazolinyl)pyridine-scandium(III) triflate complex (1) have been accomplished. The alpha,beta-unsaturated 2-acyl imidazoles were synthesized in high yields through Wittig olefination. A short, enantioselective synthesis of the alkaloid (+)-heliotridane has been accomplished utilizing this methodology and a 2-acyl imidazole cleavage and cyclization. This methodology was then extended to the one-pot asymmetric synthesis of 2-substituted indoles.
Evans
David A
DA
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA. evans@chemistry.harvard.edu
Fandrick
Keith R
KR
D000478:Alkylation; D002384:Catalysis; D007093:Imidazoles / Q000737:chemistry*; D015394:Molecular Structure; D011758:Pyrroles / Q000737:chemistry*; D011763:Pyrrolizidine Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D007093:Imidazoles; D011758:Pyrroles; D011763:Pyrrolizidine Alkaloids; C518047:heliotridane