Diastereoisomeric atropisomers of peri-substituted naphthamides: synthesis, stereoselectivity and stability
作者:Jonathan Clayden、Neil Westlund、Francis X. Wilson
DOI:10.1016/s0040-4039(99)01644-5
日期:1999.11
8-Formyl-1-naphthamides can be made by perilithiation of 1-(dimethylaminomethyl)-naphthalene, quenching the organolithium with a carbamoyl chloride and subjecting the product amine to a Polonovski reaction. The naphthamides react stereoselectively with nucleophiles to give predominantly the syn atropisomers of the product alcohols. Oxidation gives ketones which also give mainly the syn atropisonner on reduction. The rate of thermal epimerisation of the products is high relative to 2-substituted 1-naphthamides: the barrier to Ar-CO rotation is ca. 90 kJ mol(-1). (C) 1999 Elsevier Science Ltd. All rights reserved.
Atropisomeric diastereoisomers from nucleophilic attack on 8-acyl-1-naphthamides
作者:Jonathan Clayden、Neil Westlund、Christopher S. Frampton
DOI:10.1039/b000670j
日期:——
Restricted rotation about the Ar–CO bond means that 1-naphthamides bearing chiral 8-substituents may exist as pairs of diastereoisomeric atropisomers. These atropisomers are formed with good to excellent stereoselectivity for the syn-diastereoisomer by the reaction of 8-formyl-1-naphthamides with organolithiums and Grignard reagents. The reduction of 8-acyl-1-naphthamides also proceeds with syn-selectivity. The product alcohols are prone to lactonisation and also to epimerisation, and some of the apparent diastereoselectivities may be the result of thermodynamic, rather than kinetic, control.