A highly-efficient palladium-catalyzed aminocarbonylation/S_NAr approach to dibenzoxazepinones

Abstract

A convenient procedure for the synthesis of dibenzoxazepinones has been developed. Utilizing the protocol of one-pot palladium-catalyzed aminocarbonylation/aromatic nucleophilic substitution (S N Ar) sequence, with 2-aminophenols and 2-bromofluorobenzenes as the substrates, the desired dibenzo[b,e][1,4]oxazepin-11(5H)-ones were prepared in moderate to excellent yields. The broad substrate scope and functional group tolerance of the reaction makes this approach a practical method for 10 the synthesis of valuable dibenzoxazepinone and its derivatives. Mechanistic studies suggest that aminocarbonylation proceeds prior to S N Ar.

Transition-Metal-Catalyzed Carbonylative Synthesis and Functionalization of Heterocycles

“…Conventional routes to benzoxazepinones and their derivatives usually involve several steps, and isolation of intermediates. In 2015, our group [29] reported a highly-efficient one-pot palladium-catalyzed amino-carbonylation/S N Ar approach to dibenzoxazepinones and pyridobenzoxazepinones (Scheme 21). 2-Aminophenol was employed as model substrates to react with 2-bromofluorobenzene or 3-bromo-2-chloropyridine.…”

Pd/C: An efficient and reusable catalyst for the synthesis of flavones via carbonylation of aryl halides

“…Palladium‐catalyzed carbonylation reaction represents a powerful method for the synthesis of heterocycles, and has achieved great success during the past decades. The application of a carbonylation reaction in flavones synthesis has also been developed by different groups Recent progress in palladium catalyzed aryl bromides with 2‐hydroxyacetophenones to form the scaffold of flavones has shown this methodology to be particularly attractive for the synthesis of flavones .…”

“…To take the classical Baker-Venkatraman method as an example, the need for acyl chloride substrates, tedious reaction procedures and relatively harsh reaction conditions have limited its practical applications. [11,12] Palladium-catalyzed carbonylation reaction represents a powerful method for the synthesis of heterocycles, [13][14][15][16][17][18][19][20][21][22][23] and has achieved great success during the past decades. The application of a carbonylation reaction in flavones synthesis has also been developed by different groups [10,13,[24][25][26][27] Recent progress in palladium catalyzed aryl bromides with 2-hydroxyacetophenones to form the scaffold of flavones has shown this methodology to be particularly attractive for the synthesis of flavones.…”

“…However, further increase the amount of DBU afforded a lower yield of flavone(Table 1, entry 13). With DBU as the base, the influence of the solvent was also checked (Table 1, entries[14][15][16][17][18][19]. Among all the solvents screened, DMSO displayed the best performance, with which a 55% yield could be obtained (Table 1, entry 5).…”

In situ generated Pd(0) nanoparticles stabilized by bis(aryl)acenaphthenequinone diimines as catalysts for aminocarbonylation reactions in water

“…Amides constitute an interesting structural motif that is often present in pharmaceuticals (Atorvastatin, Mosapride, Imatinib, Nitroxazepine) [1][2][3] as well as in biologically active compounds (Acetaminophen, Aniracetam, Methacetin). 4,5 Amides are also important building blocks for the synthesis of numerous pesticides, color pigments and natural products 6 .…”