TY  - JOUR
A1  - Heydenreich, Matthias
A1  - Wolf, G.
A1  - Woller, Jochen
A1  - Kleinpeter, Erich
T1  - Restricted rotation of the amino group and ring inversion in highly substituted anilines. A dynamic NMR and computational study
N2  - The reaction of cyclic ylidene malononitriles with acetylene (di)carboxylic acid esters led to the production of nine bicyclic systems incorporating highly substituted (5/6) anilines. The free energy of activation (DeltaG(#)) for the restricted rotation about the aniline-NH2 bond was experimentally measured in each case and a correlation was evident between the increase in steric strain in the ground state, the electron withdrawing capabilities of the ring substituents, and a reduction in the rotational barrier. For four of the compounds, the slow ring interconversion (chairreversible arrowchair) for the annelated saturated seven-membered ring that formed part of the bicyclic system was also evident. In these four compounds, both dynamic processes were also studied theoretically using ab initio methods whilst the ring interconversion was additionally studied using molecular dynamic simulations. The interconversion between the two stable chair forms was deemed to occur via a conformation series consisting of chairreversible arrowboatreversible arrowtwist-boatreversible arrowboatreversible arrowchair. (C) 2004 Elsevier Ltd. All rights reserved
Y1  - 2004
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Woller, Jochen
A1  - Wolf, Gunter
A1  - Koch, Andreas
A1  - Kempter, Gerhard
A1  - Pihlaja, Kalevi
T1  - Configuration and stereodynamics of exo/endoisomeric push-pull alkenes of pentadiene structure
Y1  - 1998
ER  -