# Aza-enolates: why no reaction at N

My understanding is that aza-enolates have an advantage over enamines in enolate-type alkylations because the reaction at N is less likely. As a result, unactivated electrophiles can be used (i.e. electrophiles that are not allylic / benzylic / $\alpha$-halo, source: Clayden et al., p. 593)

Question: why is the lone pair on N in aza-enolates less reactive?

• From how I understand it, the problem with enamines + unactivated electrophiles is self-condensation. This naturally prevented in the N-enolate. – logical x 2 Oct 15 '17 at 13:46
• @deus ex machina So would you say that the raction at N isn't a problem at all? Why? – GingerBadger Oct 28 '17 at 10:06
• Because the n-enolate prevents an electrophilic site – logical x 2 Oct 28 '17 at 10:58
• @deusexmachina No I mean, the enolate / enamine acting as a nucleophile at N. Because although the carbon will be the soft nucleophilic centre, the electron density on N will be greater, so why won't "harder" electrophiles react with it? – GingerBadger Oct 28 '17 at 11:02
• @deusexmachina From Clayden, Ed. 2, p. 592: "There is, however, a major problem with enamines: reaction at nitrogen. Less reactive alkylating agents -- simple alkyl halides such as methyl iodide, for example -- react to a significant degree at N rather at C. The product is a quaternary ammonium salt, which hydrolyses back to the starting material and leads to low yields". – GingerBadger Oct 28 '17 at 11:04