Catalytic enantioselective [3 + 2]-cycloadditions of diazoketone-derived aryl-substituted carbonyl ylides.
An evaluation of alpha-aryl-alpha-diazodiones in tandem carbonyl ylide formation-enantioselective [3 + 2]-cycloaddition reactions is described. Such substrates were designed to allow investigation of the electronic characteristics of the dipole upon asymmetric induction. Intramolecular cycloadditions (with a tethered alkene dipolarophile) were found to occur in good to quantitative yields, with a difference in ee exhibited by the two electronically different diazodiones 8 and 9. Intermolecular cycloadditions using diazodiones 12 and 13 with DMAD and arylacetylenes 16-18 again demonstrated that electronics play a key role in determining the outcome of the cycloaddition reactions. Enantioselectivities of up to 76% were observed.
Hodgson
David M
DM
Dyson Perrins Laboratory, Department of Chemistry, University of Oxford, South Parks Road, UK. david.hodgson@chem.ox.ac.uk
Glen
Rebecca
R
Grant
Guy H
GH
Redgrave
Alison J
AJ