Aliphatic C-H/pi and Heteroatom/pi Interactions in N-Aryl-3,4-(9 ',10 '-dihydroanthracene-9 ',10 '-diyl)succinimides

作者：Raimondi Laura; Benaglia Maurizio; Cozzi Franco^*

来源：European Journal of Organic Chemistry, 2014, 2014(23): 4993-4998.

DOI：10.1002/ejoc.201402288

• Conformation analysis
• Pi interactions
• Noncovalent interactions
• Through-space interactions

A series of N-aryl-3,4-(9',10'-dihydroanthracene-9',10'-diyl)-succinimides have been synthesized as model compounds to study the interaction of an aromatic pi system with aliphatic H atoms and heteroatoms such as oxygen, sulfur, and fluorine. The steric requirements of the rigid scaffold forces the N-aryl residue and a benzene ring of the dihydroanthracenyl moiety to adopt an edge-to-face conformation in which one of the ortho-substituents of the N-aryl group interacts with the pi system. The succinimides were generally obtained as mixtures of isomers and their ratios were considered as a function of the substitution pattern at the ortho positions of the N-aryl residue. The experimentally observed ratios were in good agreement with those predicted computationally by DFT calculations at the BMK/cc-pVDZ level of theory. From this study it was concluded that in these systems the aliphatic C-H/pi interaction is mildly stabilizing and, to a certain extent, capable of overcoming unfavorable steric effects. On the other hand, the interaction of a pi system with oxygen, sulfur, or fluorine atoms was destabilizing. When methyl or ethyl groups were allowed to compete with oxygen and fluorine for interaction with the benzene ring, C-H/pi interactions were consistently observed to preferentially occur despite unfavorable steric effects.

• 出版日期2014-8