Journal of the American Chemical Society · 2009 · 243 citations · 22 references
Natural SciencesChemistryCatalysisOrganic ChemistryOrganometallic ChemistryHeterocycle SynthesisHeterocyclic ChemistryHeterocyclic CompoundsOrganic SynthesisAromatic Ring ExpansionAsymmetric Heterocycle SynthesisEnantioselective SynthesisHeterocycle FunctionalizationRing-forming ReactionsSubstrate ScopeSubstrate Scope ExpansionTransition-metal-catalyzed Heterocycle Synthesis
The asymmetric gold(I)-catalyzed ring expansion of 1-allenylcyclopropanols is described. The method provides synthetically valuable cyclobutanones with a vinyl-substituted quaternary stereogenic center in high enantioselectivities and yields. The method shows a broad substrate scope, tolerating protected alcohols and amines, alkenes, unsaturated esters, and acetals. The reaction is easily adjustable to large-scale synthesis, leading to product formation without significant loss of selectivity or yield with only 0.5 mol% catalyst loading.
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A Powerful Chiral Counterion Strategy for Asymmetric Transition Metal Catalysis
Gregory L. Hamilton, Eun Joo Kang, Miriam Mba et al. · Science · 2007 · 902 citations