Organic Letters · 2020 · 18 citations · 52 references
Natural SciencesChemistryCatalysisOrganometallic ChemistrySynthetic Medicinal ChemistryAmino Acid ChemistryCatalyst SynthesisCatalytic MechanismsOrganic SynthesisAlkylation CatalysisAlkylation ProcessesAlkylation ReactionsAmino Acid EstersEnantioselective SynthesisSubstrate ScopeSubstrate Scope ExpansionSubstrate Scope Screening
A versatile synthetic protocol of aza-Friedel-Crafts alkylation has been developed for the synthesis of quaternary α-amino esters. This operationally simple alkylation proceeds under ambient conditions with high efficiency, regioselectivity, and an exceptionally broad scope of arene nucleophiles. A key feature of this alkylation is the role associated with the silver(I) salt counteranions liberated during the reaction. Taking advantage of a phase-transfer counteranion/Brønsted acid pair mechanism, we also report a catalytic enantioselective example of the reaction.
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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