Synthesis of pyrido[1,2-a]benzimidazoles by photo-stimulated C–N bond formation via SRN1 reactions
摘要:
The photo-stimulated cyclization of 2-(2-halophenylamino)pyridines in liquid ammonia afforded pyrido [1,2-a]benzimidazoles via S(RN)1 mediated C-N bond forming reactions in moderate to excellent yields (58-94%). This general synthetic strategy was also extended to a 2-(2-bromophenylamino)pyrazine to give pyrazino[1,2-a]benzimidazole. Attempts to employ this reaction using N-(2-chlorophenyl)-3-isoquinolinamine, however, resulted in C-C bond formation generating 7H-indolo[2,3-c]isoquinoline. (C) 2013 Elsevier Ltd. All rights reserved.
Pd / DIBPP催化脱芳香化羰基化反应合成吡啶并[ 2,1- b ]喹唑啉-11-酮和双吡啶[1,2-a:2',3' - d ]嘧啶-5-酮
摘要:
通过使用1,3-双(二异丁基膦基)丙烷(DIBPP)作为配体的钯催化的脱芳构羰基化反应,可以轻松合成N杂环。从N-(2-溴苯基)吡啶-2-胺中定量获得吡啶并[2,1- b ]喹唑啉-11-酮和二吡啶并[1,2-a:2',3'- d ]来自3-溴-N-(吡啶-2-基)吡啶-2-胺的嘧啶-5-酮,产率高达84%。也可以在不分离化合物1和另外的钯催化剂的情况下实现环羰基化。
The first Pd-catalyzedcyclization of N-aryl-2-aminopyridines with 2-iodobenzoic acids for the synthesis of phenanthridinones through C–H bond activation under very low catalyst loadings (down to 0.1 mol% Pd) in water is reported. This protocol features a broad substrate scope and provides easy efficient access to various phenanthridinones.