Tandem Parham cyclisation––α-amidoalkylation reaction in the synthesis of the isoindolo[1,2- a ]isoquinoline skeleton of nuevamine-type alkaloids
摘要:
C-12b substituted isoindolo[1,2-a]isoquinolones 4 are prepared efficiently via a tandem Parham cyclisation-alpha-amidoalkylation reaction. Thus, Parham cyclisation on imide I generates a 12b-hydroxy isoindolo[1,2-a]isoquinolone, which is an immediate precursor of an N-acyliminium ion. Intermolecular alkylation with different pi-nucleophiles (allyl silanes or enol ethers) is accomplished upon treatment with Lewis acids (BF3.OEt2, TiCl4) to obtain nuevamine-type derivatives in high yields (69-95%) under mild conditions. (C) 2003 Elsevier Ltd. All rights reserved.
Chiral Brønsted Acid-Catalyzed Enantioselective α-Amidoalkylation Reactions: A Joint Experimental and Predictive Study
作者:Eider Aranzamendi、Sonia Arrasate、Nuria Sotomayor、Humberto González-Díaz、Esther Lete
DOI:10.1002/open.201600120
日期:2016.12
Enamides with a free NH group have been evaluated as nucleophiles in chiralBrønstedacid‐catalyzedenantioselective α‐amidoalkylation reactions of bicyclic hydroxylactams for the generation of quaternary stereocenters. A quantitative structure–reactivity relationship (QSRR) method has been developed to find a useful tool to rationalize the enantioselectivity in this and related processes and to orient