Parham-Type Cycliacylation with Weinreb Amides. Application to the Synthesis of Fused Indolizinone Systems
摘要:
[GRAPHIC]Weinreb amides behave as efficient internal electrophiles in Parham-type cycliacylation reactions. Thus, aryl- and heteroaryllithiums generated by lithium-halogen exchange undergo intramolecular cyclization to give fused indolizinone systems as pyrrolo[1,2-b]isoquinolines, thieno[2,3-f]indolizinones, and pyrrolo[1,2-b]acridinones in high yields.
An efficient entry to pyrrolo[1,2-b]isoquinolines and related systems through Parham cyclisation
摘要:
Aryllithiums generated by lithium-iodine exchange undergo intramolecular cyclisation to give pyrrolo[1,2-b]isoquinolines, in high yields. The best results were obtained when Weinreb or morpholine amides were used as internal electrophiles. The procedure has been extended to the preparation of seven and eight membered rings, opening a route to benzazepine and benzazocine skeletons. (c) 2004 Elsevier Ltd. All rights reserved.