Asymmetric deprotonation of N,N-dihexyl-1-naphthamides to provide atropisomers of N,N-dihexyl-2-alkyl-1-naphthamides
作者:S. Thayumanavan、Peter Beak、Dennis P. Curran
DOI:10.1016/0040-4039(96)00439-x
日期:1996.4
Asymmetric deprotonation of N,N-dihexyl-1-naphthamide using sec-butyllithium / (-)-sparteine followed by reactions with methyl or ethyl alkylation reagents give the atropisomers of N,N-dihexyl-2-alkyl-1-naphthamide with 50% and 55% ee, respectively. (C) 1996 Elsevier Science Ltd
Barriers to rotation about the chiral axis of tertiary aromatic amides
作者:Anjum Ahmed、Ryan A. Bragg、Jonathan Clayden、Lai Wah Lai、Catherine McCarthy、Jennifer H. Pink、Neil Westlund、Samreen A. Yasin
DOI:10.1016/s0040-4020(98)00814-x
日期:1998.10
The barrier to rotation about the aryl-carbonyl bond in 40 tertiary aromatic amides was determined by variable temperature NMR spectroscopy (for rapid rotations) or by following the interconversion of atropisomers (for slower rotations). Empirical guidelines to the rate of ArCO bond rotation in hindered tertiary aromatic amides, and hence the stability of the atropisomeric stereoisomers of axially
Despite the widespread use of naphthamide atropisomers in biologically active compounds and asymmetric catalysis, few catalytic methods have succeeded in the enantioselective synthesis of these compounds. Herein, a chiral Brønsted acid (CBA) catalysis strategy was developed for readily scalable dynamic kinetic resolution of challenging ortho-formyl naphthamides with pyrrolylanilines. The chiral axis of the