Lewis acid-promoted cascade reaction of primary amine, 2-butynedioate, and propargylic alcohol: a convenient approach to 1,2-dihydropyridines and 1H-pyrrolo[3,4-b]pyridine-5,7(2H,6H)-diones
摘要:
1,2-Dihydropyridine-5,6-dicarboxylates were efficiently constructed through a cascade reaction of primary amine, 2-butynedioate and propargylic alcohol in the presence of Lewis acid under mild conditions. As exceptional, 1H-pyrrolo[3,4-b]pyridine-5,7(2H,6H)-diones were approached when the primary amine was methylamine. Possible mechanism for the formation of 1,2-dihydropyridine skeleton is proposed. The process involves 1,3,4-pentatrien-1-amine as a key intermediate that formed in situ by trapping allenic carbocations with enamines. (C) 2013 Elsevier Ltd. All rights reserved.
One-pot esterification-click (CuAAC) and esterification–acetylene coupling (Glaser/Eglinton) for functionalization of Wang polystyrene resin
作者:Sagi Eppel、Moshe Portnoy
DOI:10.1016/j.tetlet.2013.07.034
日期:2013.9
We report three new sets of one-pot reactions for functionalization of Wang polystyrene resin and its derivatives. We first show that it is possible to combine esterification and CuAAC (Copper-Catalyzed Alkyne-Azide Cycloaddition) in a one-pot reaction with a very high yield. We also demonstrate for the first time that it is possible to combine esterification with either Glaser or Eglinton acetylene-couplings in a one-pot reaction. Finally, we show that the esterification, CuAAC, and Glaser-coupling reactions are all compatible with each other, and it is possible to run in parallel esterification/CuAAC and esterification/Glaser coupling in a single vessel. All reactions are performed at room temperature while the only separation method required is filtering and washing the resin. (C) 2013 Elsevier Ltd. All rights reserved.