93960-14-6Relevant articles and documents
Morpholine-based immonium and halogenoamidinium salts as coupling reagents in peptide synthesis
El-Faham, Ayman,Albericio, Fernando
, p. 2731 - 2737 (2008/09/19)
(Chemical Equation Presented) Here we describe a new family of N-form immonium-type coupling reagents that differ in their carbocation skeleton structure. The N-methylpiperazine derivative failed to form immonium salts, while the thiomorpholine derivative did not give better results than the coupling reagents currently used. The presence of the morpholine had a marked influence on the solubility and stability as well as the reactivity of the reagent. Finally, the fluoroamidinium salt performed extremely well in the presence of only 1 equiv of base, thereby confirming the effect of the proton acceptor in the reaction.
