Copper-Catalyzed C–N Bond Formation/Rearrangement Sequence: Synthesis of 4H-3,1-Benzoxazin-4-ones

Abstract

A facile and efficient copper-catalyzed method for the synthesis of 4H-3,1-benzoxazin-4-one derivatives has been developed. This procedure is based on a tandem intramolecular C-N coupling/rearrangement process. This method would provide a new and useful strategy for construction of N-heterocycles.

Silver‐Mediated Synthesis of 4H‐Benzoxazin‐4‐ones by Intramolecular Decarboxylative O‐Acylation Reactions with α‐Oxocarboxylic Acid

“…Other notable methods are transition‐metal‐catalyzed or transition‐metal‐free syntheses of 4 H ‐benzoxazin‐4‐ones from 2‐azidoalkynylbenzene, 2‐arylindole and N ‐benzoyl‐2‐iodobenzamide . Very recently, Du et al described the CoCl 2 / tert ‐butyl hydroperoxide (TBHP) mediated intramolecular oxidative cyclization of N ‐(2‐formylphenyl)amides.…”

Palladium-catalyzed synthesis of 4H-benzo[d][1,3]oxazin-4-ones and N-(2-cyanophenyl)benzamides via tert-butyl isocyanide insertion

“…Previously, our group reported a facile and efficient copper-catalyzed route to 4H-benzo [d] [1,3]oxazin-4-ones through a tandem intramolecular C-N coupling/rearrangement process. 11 Based on a continuation of our interest in synthesizing this kind of compounds, we have developed a simple and efficient palladium-catalyzed method to 4H-benzo [d] [1,3]oxazin-4-ones via isocyanide insertion from N-(2-bromophenyl)-benzamides.…”

Palladium‐Catalyzed Olefination of 4H‐Benzo[d][1,3]oxazin‐4‐one Derivatives with Activated Alkenes via Preferential Cyclic Imine‐N‐Directed Aryl C‐H Activation

“…2‐Phenyl‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 2‐([1,1′‐Biphenyl]‐4‐yl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13b] 2‐( p ‐tolyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 2‐(4‐Ethylphenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13c] 2‐(m‐Tolyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13d] 2‐(4‐( tert ‐butyl)phenyl)‐4H‐ben zo[d][1,3]oxazin‐4‐one,[13e] 2‐(4‐Methoxyphenyl)‐4H‐benzo[d][1,3]oxazin –4‐one,[13a] 2‐(4‐Chlorophenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13b] 2‐(4‐Bromophenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13b] 2‐(4‐(Trifluoromethyl) phenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 2‐(o‐Tolyl)‐4H‐benzo[d][1,3] oxazin‐4‐one,[13f] 2‐(2‐(Trifluoromethyl)phenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13e] 7‐Chloro‐2‐phenyl‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 7‐Chloro –2‐( p ‐tolyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13g] 7‐Chloro‐2‐(4‐chlorophenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13g] 6‐Chloro‐2‐( p ‐tolyl)‐4H‐benzo[d] [1,3]oxazin‐4‐one,[13h] 2‐Phenyl‐7‐(trifluoromethyl)‐4H‐benzo[d][1,3] oxazin‐4‐one,[13i] 6,7‐Dimethoxy‐2‐( p ‐tolyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13j] 8‐Methyl‐2‐phenyl‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 2‐(Thiop hen‐2‐yl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 2‐(Furan‐2‐yl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13a] 2‐(3‐Methoxyphenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13b] 2‐(3‐Chlorophenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one,[13c] 2‐(3‐Bromophenyl)‐4H‐benzo[d][1,3]oxazin‐4‐one. [13k]…”