Macroscopic chiral symmetry breaking in gelation of Fmoc-amino acids: homochiral selective secondary nucleation promoted by the choice of solvent or stirring

Abstract

A racemic mixture of N-Fmoc-protected phenylalanine (2) or tryptophan (3) was found to spontaneously afford a gel enriched in either the L- or the D-form of their enantiomers stochastically. Homochiral selective secondary nucleation, promoted by the choice of solvent or stirring, was suggested as the key process for the observed phenomenon.