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‐aminoesters 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. 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 without any catalyst.