Alkoxyamine-derived Formamidines: Configurational Control and Molecular Folding

Abstract

N,N'-Disubstituted formamidines, and amidines in general, have very rich configurational, conformational, and tautomeric diversities. As part of an effort to incorporate alkoxyamine-derived formamidine units into foldamers, the first evidence for the isolation of the up-to-now unknown E isomer, the conditions for its exclusive formation, its stability and self-assembly properties, and its configurational isomerization to its much more common Z counterpart are reported. Considering the distinctly different H-bonding patterns displayed by both E and Z isomers, such configurational control may find applications in self-assembly, molecular recognition, and biomimetic systems.

Peptidines: glycine-amidine-based oligomers for solution- and solid-phase synthesis

“…Interestingly, other authors have observed that amidines containing electron-donating N 2 substituents such as alkoxy substituents readily exist as cis / trans mixtures with preferences for the cis geometry. 27 , 28 Although our synthesis platform is currently incompatible with such electron-rich groups on N 2 , the possibility exists that the τ geometry can be modulated through substituent effects. Additionally, we tested the hydrolytic stability of several compounds in PBS and observed minimal hydrolysis suggesting that peptidines may be suitable for use in biological contexts (ESI Fig.…”