Abstract
On deprotonation by lithium bistrimethylsilylamide (LBTSA), 2-phthalimidoacetophenone
(1) is quantitatively converted to 6H,12H-isoindolo [2,1-a]-6,7a-dihydroxyquinolin-12-one (2); weaker bases proved much less effective.
Thermal dehydration of 2 to vinilogous
imide 3, then the AlCl3-catalyzed
aminolysis by (1S)-arylethylamines afforded
(1S)-amides of 2-(2′-carboxyphenyl)-4-hydroxyquinolines
(5-7).
This sequence represents an efficient assembling of novel chiral
heterocycles, potentially useful in enantioselection as ligands
or chiral selectors. In situ prepared Pd(II) complexes of 5-7 exhibited
catalytic activity in allylic alkylation of 1,3-diphenyl-1-acetoxyprop-2-ene
(8) by dimethylmalonate anion; the complex
of 7 afforded the highest (64%) enantiomeric
excess of 1,3-diphenyl-1-dimetylmalonylprop-2-ene (9).
Key words
quinolines - amides - stereoselective synthesis - alkylations - heterocycles
