Skip to main content
. Author manuscript; available in PMC: 2018 Jul 1.
Published in final edited form as: Synlett. 2017 Mar 10;28(12):2407–2421. doi: 10.1055/s-0036-1588778

Figure 3.

Figure 3

Free energy reaction profile which shows that the overall activation barrier for carbonyl-catalyzed deprotonation of glycine to form a stabilized glycine carbanionis composed of the barrier for conversion of the reactants to the iminium cation and, the barrier for deprotonation of this cation by lyoxide anion. The carbonyl-catalyzed reactions were generally followed by monitoring protonation of the carbanion reaction intermediate in DOD to give deuterium-labeled glycine. However, the disappearance of DPL was monitored during formation of the Claisen-type adduct shown in Chart 6.64