Asymmetric Synthesis of 3-Substituted 4-Oxoesters Using the SAMP-/RAMP-Hydrazone Method

Radical Umpolung: Efficient Options for the Synthesis of 1,4‐Dicarbonyl Compounds

“…By employing the principle of auxiliary control in asymmetric synthesis, our group developed a number of approaches for the synthesis of highly enantioenriched 1,4‐dicarbonyl compounds, such as the oxidative coupling and the tert ‐butyl bromoacetate α‐alkylation of lithiated SAMP/RAMP hydrazones, as well as an umpolung strategy with the broadly applicable lithiated α‐amino nitriles as acyl anion equivalents (Scheme a). The classical catalytic approach to 1,4‐dicarbonyl compounds is the Stetter reaction, and after first attempts towards enantioselective variants in the early 1990s, intermolecular catalytic Stetter reactions were developed by our group as well as the groups of Glorius and Rovis (Scheme b) .…”