Palladium‐Catalysed Multicomponent Aminocarbonylation of Aryl or Heteroaryl Halides with [Mo(CO)₆] and Aryl‐ or ­Heteroarylamines Using Conventional Heating

Abstract

Di(hetero)arylamides have been synthesized in short reaction times by palladium-catalysed multicomponent aminocarbonylation of either electron-deficient or electron-rich heteroaryl halides and p-iodoanisole with several arylamines bearing either electron-donating or -withdrawing groups and aminopyridines using [Mo(CO) 6 ] as a solid CO source and conventional heating. Starting from heteroaryl bromides, a palladacycle with tBu 3 PHBF 4 as ligand is required together with DBU as a base in dioxane and a temperature of 125°C. From (hetero)aryl iodides, Pd(OAc) 2 without a ligand and DBU were used in dioxane at 110°C. Under the latter conditions we were able to apply this reaction to deactivated aminopyridines to obtain the corresponding di(hetero)arylamides.

Dual Role of Acetate in Copper(II) Acetate Catalyzed Dehydrogenation of Chelating Aromatic Secondary Amines: A Kinetic Case Study of Copper‐Catalyzed Oxidation Reactions

“…1 H NMR (300 MHz, CDCl 3 ): δ = 9.93 (br. s, 1 H), 8.61 (d, J = 4.8 Hz, 1 H), 8.30 (d, J = 7.8 Hz, 1 H), 7.90 (dt, J = 7.2, 1.2 Hz, 1 H), 7.70 (d, J = 9.0 Hz, 2 H), 7.47 (t, J = 7.8 Hz, 1 H), 6.93 (d, J = 9.0 Hz, 2 H), 3.82 (s, 3 H) ppm …”

“…The solvent was removed under reduced pressure, and the crude product was subjected to column chromatography (silica gel, 0-10 % EtOAc/CH 2 Cl 2 ). The yield was 72 mg (71 % 9, 149.2, 146.1, 138.1, 136.6, 127.2, 122.1, 121.6, 113.1, 49.7, 33.2, 24.3 [70] 1-d 2 : Lithium aluminum deuteride (LiAlD 4 ) (36 mg, 0.86 mmol) was suspended in dry THF (10 mL) in a round-bottom flask (50 mL) under argon and cooled in an ice bath. N-(4-Methoxyphenyl)-2-picolinamide (100 mg, 0.44 mmol) in dry THF (2.0 mL) was added slowly, and the mixture was heated at reflux for 12 h. The mixture was then cooled in an ice bath, and the reaction was quenched by the addition of water (1.0 mL), which was followed by the addition of an NaOH solution (5 % v/v, 20 mL).…”

Microwave‐Heated Transition Metal‐Catalyzed Coupling Reactions

“…n-Butylamine, piperidine, and water were successfully employed as the nucleophiles and a range of benzamide and benzoic acid products were produced in 65-83% yields after microwave heating at 150 • C for 15 min (Scheme 15.124). Following this first study, numerous investigations of the microwave-promoted aminocarbonylation reaction tuned with respect to the starting material, such as aryl chlorides [239], heteroaryl halides [240,241], triflates [242], and alkenyl phosphates [243], were reported.…”

Carbonylative annulation of unsaturated compounds using molybdenum hexacarbonyl: an efficient synthesis of 2(1H)-quinolones

“…In this regard, several groups have reported on various CO-gas free methods including microwave-assisted palladium-catalyzed Mo(CO) 6 -mediated carbonylative coupling reactions. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] Recently we also reported a facile route to diaryl ketones through palladium-catalyzed three-component cross-coupling of aryl and heteroaryl halides, Mo(CO) 6 and boronic acids and offered a mild base/solvent combination for efficient microwave-free extrusion of carbon monoxide in the course of the reaction. 33 Continuing our interest in carbonylation reactions, we further attempted to synthesize (dihydro)quinolones via carbonylative annulation reactions of readily available 2-iodoanilines and unsaturated compounds.…”