e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Bulletin of the Chemical Society of Japan
Restricted rotation involving the tetrahedral carbon. LV. Differential effects of the peri-substituents on the rotational barriers in 9-ethyl-, 9-allyl-, and 9-benzyltriptycenes.
G Yamamoto, M Oki
Index: Murata; Mori; Oki Bulletin of the Chemical Society of Japan, 1984 , vol. 57, # 7 p. 1970 - 1975
Energy barriers to rotation about the bridgehead-to-substituent bond in 9-ethyl-, 9-allyl-, and 9-benzyltriptycene derivatives with varying degrees of peri-substitution were studied by dynamic NMR and in one case by the classical kinetic method. In the singly peri-substituted series (1, 4-dimethoxy derivatives) the barrier decreases in the order of 9-ethyl> 9-allyl> 9- benzyl. In the doubly peri-substituted series (1, 8-dichloro derivatives) the barriers are ...
