Controlling dynamic stereoisomerism in transition-metal folded baskets

We synthesized chiral molecular baskets (R sub(3)/S sub(3))-1, containing three pyridine rings at the rim of a bowl-shaped platform. Each pyridine was tethered to the platform via a CH(CH) sub(3) stereogenic center. In line with prior studies, we found that chiral basket (R sub(3))-1 would coordinate to Ag(I) cation forming a Ag(I)-(R sub(3))-1 complex ( Delta G degree = -5.9 kcal mol super(-1) at 298.0 K). Furthermore, we used spectroscopic methods ( super(1)HNMR, UV-Vis and CD) to establish that the CH(CH) sub(3) stereogenic center with R configuration in Ag(I)-(R sub(3))-1 would direct the twisting of the pyridine rings at the rim in a clockwise orientation (P configuration). UV-Vis and CD spectra of Ag(I)-(R sub(3))-1(P) were also computed (TD-DFT; BHLYP/SV(P), TZVP), showing good agreement with the experimental data. Controlling dynamic stereoisomerism in basket-like systems is important and the results of this study will be useful for examining the relationship between chiral recognition and reactivity in gated and confined environments.