Relationship between rotational barriers and structures in N–C axially chiral 3,4-dihydroquinolin-2-one and 3,4-dihydrobenzoquinolin-2-one

Yuya Suzuki (1) , Isao Takahashi (1) , Yasuo Dobashi (2) , Hiroshi Hasegawa (2) , Christian Roussel (3) , Osamu Kitagawa (1)

1 Department of Applied Chemistry
2 TUPLS - Tokyo University of Pharmacy and Life Sciences
3 ISM2 - Institut des Sciences Moléculaires de Marseille

The rotational barrier around the N-C chiral axis in N-(2-tert-butylphenyl)-3,4-dihydrobenzoquinolin-2-one was found to be 6 kcal/mol lower than that in N-(2-tert-butylphenyl)-3,4-dihydroquinolin-2-one. X-ray crystal structures and H-1 NMR spectra of both compounds indicate that the significant decrease in the rotational barrier in benzoquinolinone is brought about by destabilization of the ground state which is highlighted by a considerable distortion of the N-C chiral axis.

Domaines: Chimie

Yuya Suzuki, Isao Takahashi, Yasuo Dobashi, Hiroshi Hasegawa, Christian Roussel, et al.. Relationship between rotational barriers and structures in N–C axially chiral 3,4-dihydroquinolin-2-one and 3,4-dihydrobenzoquinolin-2-one. Tetrahedron Letters, 2015, 56 (1), pp.132 - 135. ⟨10.1016/j.tetlet.2014.11.040⟩. ⟨hal-01471010⟩