1314922-75-2Relevant academic research and scientific papers
Cucurbit[8]uril recognition of rapidly interconverting diastereomers
Joseph, Roymon,Masson, Eric
, p. 632 - 641 (2015/10/19)
The diastereoselectivity of Cucurbit[8]uril (CB[8]) binding was probed towards a series of rapidly interconverting diastereomers containing a Caryl-Caryl chiral axis and at least one other stereocenter. Relative binding affinities of up to 4.9 were determined when CB[8] interacted with ortho, meta, ortho′-substituted biphenyls bearing a chiral dialkylsulfonium substituent at their meta-position. Diastereoselectivities of up to 2.4-fold were obtained for ortho′-substituted 2-phenylpyridinium derivatives that bear a chiral myrtenyl N-substituent prone to CB[8] binding.
How space-filling is a pyridine lone pair?
Mazzanti, Andrea,Lunazzi, Lodovico,Lepri, Susan,Ruzziconi, Renzo,Schlosser, Manfred
experimental part, p. 6725 - 6731 (2012/01/19)
The torsional barriers of 2′-substituted 2-arylpyridines have been probed experimentally (by using dynamic NMR spectroscopy) and computationally (by using density functional theory). Due to the compressibility of the lone pair, the torsional barriers of the arylpyridines are up to 4.2 kcal/mol smaller than those of the carba-analogous biphenyls. Furthermore, the ground states of the 2-arylpyridines are less twisted than those of the biphenyls. Finally, due to an out-of-collinearity distortion, the intramolecular repulsion is attenuated in both rotational transition states, in the syn coplanar conformer (in which the pyridine nitrogen and the substituent R face each other) and in the anti coplanar conformer (in which they are on opposite sides of the molecule).
