Direct Access to Cumbersome Aminated Quaternary Centers by Hyperbaric Aza‐Michael Additions
The aza-Michael addition of secondary amines to α,β- or β,β-disubstituted α,β-unsaturated esters was efficiently achieved under high pressure (10-16 kbar) in protic solvents in the absence of any catalyst. The expected cumbersome β-aminesters bearing a tertiary amine directly connected to a quaternary carbon atom could be isolated in fair to good yields. By using α,β,δ,γ,-unsaturated esters (alkyl sorbate), the addition took place regioselectively in a 1,6 manner and afforded the β,γ-unsaturated δ-aminoesters.