Late-Stage Functionalization of (R)-BINOL-Based Diazacoronands and Their Chiral Recognition of α-Phenylethylamine Hydrochlorides

Abstract

Five BINOL-based hosts with a variable macroring size were synthesized in a two-step postfunctionalization protocol by double N-benzylation followed by BMS-mediated reduction of tertiary amide groups (53−93%). UV−vis titration in MeCN reveals that all hosts exhibit a preference for the (R)-enantiomer over the (S)-enantiomer of PEA−HCl. The enantioselectivity depends on the number of hydrogen bond (HB) acceptors and the size and flexibility of the macroring. The highest enantiodiscrimination was observed for the 20-membered host 10, containing six HB acceptors (K R /K S = 2.13).

Alkylammonium Cation Affinities of Nitrogenated Organobases: The Roles of Hydrogen Bonding and Proton Transfer

“…In this context, understanding and controlling the metabolism of these neurotransmitters by monoaminoxidase enzymes [26–30] allows the treatment of various types of mental and neurodegenerative disorders [31,32] . The binding or recognition of a molecule that contains an ammonium group constitutes a subtle balance of all the interactions between host and guest [33–39] where the establishment of hydrogen bonds is often crucial [40–44] . In other cases, depending on the characteristics of the biochemical process and the species involved, a proton transfer from the ammonium cation to other functionality takes place [45–47] …”

“…[31,32] The binding or recognition of a molecule that contains an ammonium group constitutes a subtle balance of all the interactions between host and guest [33][34][35][36][37][38][39] where the establishment of hydrogen bonds is often crucial. [40][41][42][43][44] In other cases, depending on the characteristics of the biochemical process and the species involved, a proton transfer from the ammonium cation to other functionality takes place. [45][46][47] On the other hand, nitrogen-containing organobases play several important roles in organic synthesis.…”

Oxidation of Sodium Deoxycholate Catalyzed by Gold Nanoparticles and Chiral Recognition Performances of Bile Salt Micelles

“…A pair of enantiomers of chiral molecules may exhibit significant differences in pharmacological activities, metabolic processes, and toxicities [11,12]. Chiral recognition is of considerable significance in life and biological sciences and has aroused widespread concern in the fields of chemistry, medicine, pharmaceuticals, material sciences, and food industries [13][14][15]. The chiral environments of the BS aggregates provide geometrical specificity for chiral recognition.…”

Chiral Recognition of Carboxylate Anions by (R)-BINOL-Based Macrocyclic Receptors

“…Since then, BINOL has been extensively used in chiral recognition [13] and exhibit excellent chiral induction in asymmetric reactions [14]. In recent years many scientists have employed this chiral molecule to create a new group of receptors, which have turned out to be appropriate for effective chiral recognition of anions [15,16,17], cations [18,19] and neutral molecules [20,21].…”

“…Recently building on our previous experience [18], herein we report on the synthesis of putative macrocyclic receptors ( R )- 1 – 3 , featuring multiple hydrogen-bonding sites and varied aliphatic linker length (Figure 1). They are thus characterized by varying size and conformation of their macrocyclic pocket, which can translate into chiral recognition abilities towards α-hydroxy and α-amino acids.…”