Formation of α-dialkylamino alkyllithium intermediates in the reaction of N,N-dialkylamides with PhMe2SiLi followed by a second lithium reagent, and their alkylation, fragmentation, cyclisation and rearrangement by proton transfer

Abstract

Tertiary amides (RCONMe₂) react with PhMe₂SiLi, followed by a second lithium reagent NuLi, to give α-dialkylamino alkyllithium intermediates R(Me₂N)CLiNu that undergo protonation 2 → 3, alkylation 2a → 3ab, β-elimination 5 → 6, intramolecular attack on an isolated double bond 9 → 10, intramolecular proton transfer 12, 17 and 22 (arrows), and fragmentation 28 and 34 (arrows), depending upon the structures of the various components R and Nu.