Lithium Intermediates during the α‐Lithiation and Subsequent α‐Substitution of Heterocyclic Amines in the Presence of CO₂

Abstract

Two interdependent steps appear to be involved in the CO2-mediated electrophilic substitution of cyclic amines in the α position. The key finding is that the lithium carbamate 1 is not lithiated with tBuLi to any extent, but reacts only after addition of electrophiles like Me3SiCl to give the desired α-substitution product 2.