Template‐directed synthesis and dynamic covalent chemistry were implemented to achieve quantitative one‐pot syntheses of homochiral helical cavities inside aromatic foldamers. One‐handed helical receptors P‐1, M‐1, P‐2 and M‐2 were assembled from their precursors in the presence of appropriate templates (d‐ and l‐tartaric acid, and d‐ and l‐sorbitol, respectively) via three sequential steps in one pot: imine‐linked chain elongation, template‐induced folding and [4+2] cycloaddition between helical turns. These helical receptors were proven to enantioselectively bind chiral guests used as the templates, and the differences between the association constants of enantiomeric guests were up to more than two orders of magnitude. The structures and binding modes of the receptors were fully characterized by single‐crystal X‐ray crystallography and 1H NMR spectroscopy.

Template‐directed synthesis and dynamic covalent chemistry were implemented to achieve quantitative one‐pot syntheses of homochiral helical cavities inside aromatic foldamers. One‐handed helical receptors P‐1, M‐1, P‐2 and M‐2 were assembled from their precursors in the presence of appropriate templates (d‐ and l‐tartaric acid, and d‐ and l‐sorbitol, respectively) via three sequential steps in one pot: imine‐linked chain elongation, template‐induced folding and [4+2] cycloaddition between helical turns. These helical receptors were proven to enantioselectively bind chiral guests used as the templates, and the differences between the association constants of enantiomeric guests were up to more than two orders of magnitude. The structures and binding modes of the receptors were fully characterized by single‐crystal X‐ray crystallography and 1H NMR spectroscopy.

Two indolocarbazole-naphthyridine foldamers 2 and 3 that fold into helical conformations were prepared. The 4-(N,N-dimethylamino)pyridine (DMAP) moiety was introduced at one end of the foldamer strands to develop foldamer-based catalysts for the site-selective acylation of polyols. These foldamers adopt helical conformations containing internal cavities capable of binding octyl β-d-glucopyranoside. The association constants were determined to be 1.9 (� 0.1) × 10 5 M À 1 for 2 and 2.1 (� 0.1) × 10 5 M À 1 for 3 in CH 2 Cl 2 at 25°C. In the presence of DMAP, 2 or 3 as the catalysts, octyl β-d-glucopyranoside was subjected to acetylation under identical reaction conditions. The DMAPcatalysed reaction afforded the random distribution of the monoacetylates (6-OAc : 4-OAc : 3-OAc : 2-OAc = 33 : 24 : 41 : 2). In contrast, foldamers 2 and 3 led to the predominant formation of 6-OAc. The relative distributions were estimated to be 6

Aromatic helical receptors P-1 and P-2 were slightly modified by aerobic oxidation to afford new receptors P-7 and P-8 with right-handed helical cavities. This subtle modification induced significant changes in the binding properties for chiral guests. Specifically, P-1 was reported to bind d-tartaric acid (K a = 35500 M À 1 ), used as a template, much strongly than l-tartaric acid (326 M À 1 ). In contrast, its modified receptor P-7 exhibited significantly reduced affinities for d-tartaric acid (3600 M À 1 ) and l-tartaric acid (125 M À 1 ). More dramatic changes in the affinities and selectivities were observed for P-2 and P-8 upon binding of polyol guests. P-2 was determined to selectively bind dsorbitol (52000 M À 1 ) over analogous guests, but P-8 showed no binding selectivity: d-sorbitol (1890 M À 1 ), l-sorbitol (3330 M À 1 ), d-arabitol (959 M À 1 ), l-arabitol (4970 M À 1 ) and xylitol (4960 M À 1 ) in 5% (v/v) DMSO/CH 2 Cl 2 at 25 � 1°C. These results clearly demonstrate that even subtle post-modifications of synthetic receptors may significantly alter their binding affinities and selectivities, in particular for guests of long and flexible chains.

We have synthesised a new aromatic foldamer based on the carbazole–pyridine oligomers that adopt helical conformations via dipole-dipole interactions and π-stacking between two ethynyl bond-linked monomers. This foldamer scaffold has...