110307-23-8Relevant articles and documents
Substrate Control in the Gold(I)-Catalyzed Cyclization of β-Propargylamino Acrylic Esters and Further Transformations of the Resultant Dihydropyridines
Miku?ek, Ji?í,Matou?, Petr,Matou?ová, Eli?ka,Janou?ek, Martin,Kune?, Ji?í,Pour, Milan
, p. 2912 - 2922 (2016/09/19)
N-Protected β-propargylamino acrylic esters with a push-pull olefinic bond afforded good to high yields of dihydropyridines upon treatment with 5% tris(2-furyl)phosphine-gold(I) chloride/silver(I) tetrafluoroborate [(TFP)AuCl/AgBF4] in anhydrous benzene. Carbamate and sulfonyl groups were employed for nitrogen protection. On a model enyne, the p-methoxybenzenesulfonyl (MBS) group was found to be a better protective group than tosyl in terms of cyclization yield, and also the yield of elimination to the corresponding 2,3,4-trisubstituted pyridines. Boc-protected dihydropyridines underwent partial deprotection/oxidation under the cyclization conditions, which enabled a more straightforward, one-pot preparation of the corresponding pyridines. In another application, an appropriately substituted derivative protected as a stable methoxycarbamate was subjected to catalytic hydrogenation affording the known precursor of paroxetine. The chemoselectivity of enyne cyclization (dihydropyridine vs. pyrrole) is governed, among other factors, by C-3 substitution. Dihydropyridines were obtained as sole products regardless of the catalyst/conditions when C-3 was unsubstituted. (Figure presented.).
Process for the preparation of aryl-piperidine esters
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, (2008/06/13)
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