Diastereoselective synthesis of atropisomers containing two non-biaryl stereogenic axes: stereochemical relay through stereogenic centres in dihydrostilbene-2,2'-dicarboxamides.
Addition of laterally lithiated tertiary aromatic amides to benzaldimines controls the formation of a new stereogenic centre adjacent to the benzaldimine aromatic ring. Drawing on the fact that such amino-substituted stereogenic centres may themselves control the conformation of amides, with amido-substituted benzaldimines we found it becomes possible to relay stereochemistry from one amide to another via this intervening stereogenic centre. A group of dihydrostilbene-2,2'-dicarboxamide derivatives bearing one or two stereogenic axes are made by this method, which demonstrates the use of combined kinetic and thermodynamic control for the relay of stereochemical information.
Clayden
Jonathan
J
School of Chemistry, University of Manchester, Oxford Road, Manchester, UKM13 9PL. clayden@man.ac.uk
Westlund
Neil
N
Frampton
Christopher S
CS
Helliwell
Madeleine
M