Tandem carbophilic addition-N-acyliminium ion cyclization for the synthesis of functionalized pyrrolo[2,1-a]isoquinolones: Key intermediates for the preparation of Erythrina-type alkaloids
作者:Izaskun Manteca、Nuria Sotomayor、María-Jesús Villa、Esther Lete
DOI:10.1016/0040-4039(96)01745-5
日期:1996.10
3-(2-trimethylsilyl-1,3-dithian-2-yl)propyllithium 11, followed by desilylation and subsequent retro-Diels-Alder reaction affords the α,β-unsaturated pyrroloisoquinolone 9b, immediate precursor of Erythrina-type alkaloids.
Triflic Anhydride Mediated Cyclization of 5-Hydroxy-Substituted Pyrrolidinones for the Preparation of α-Trifluoromethylsulfonamido Furans
作者:Albert Padwa、Paitoon Rashatasakhon、Mickea Rose
DOI:10.1021/jo0341970
日期:2003.6.1
(Tf(2)O) in pyridine resulted in the formation of various substituted sulfonamidofurans. The suggested mechanism involves initial formation of an iminium ion which is subsequently transformed into a transient imino triflate. Cyclization of the highly electrophilic imine onto the oxygen atom of the adjacent carbonyl group generates an imino dihydrofuran intermediate. This species reacts further with
Metalation <i>vs </i>Nucleophilic Addition in the Reactions of <i>N</i>-Phenethylimides with Organolithium Reagents. Ready Access to Isoquinoline Derivatives <i>via</i> <i>N</i>-Acyliminium Ions and Parham-Type Cyclizations
作者:M. Isabel Collado、Izaskun Manteca、Nuria Sotomayor、María-Jesús Villa、Esther Lete
DOI:10.1021/jo962155o
日期:1997.4.1
Sequential carbophilic addition of organolithium reagents and N-acyliminiumioncyclization of N-phenethylimides 1 affords the substituted isoquinolones 3 in high yields, with the possibility of varying the substituent at the C-1 position of the isoquinoline ring by changing the organolithium reagent. Ready access to the isoquinolinenucleus via Parham-typecyclization of imides 2 is also described