A General Ruthenium‐Catalyzed Synthesis of Aromatic Amines

Abstract

Simple as that: The synthesis of aromatic amines from aliphatic amines proceeds under transfer hydrogenation conditions (see scheme). By applying the Shvo catalyst, general applicability is shown in the conversion of a variety of functionalized anilines and aliphatic amines. This base‐ and salt‐free method can be an excellent alternative to the known synthesis of anilines.

One pot synthesis of cyclohexanone oxime from nitrobenzene using a bifunctional catalyst

“…However, cyclohexanone 9 was not formed if 4 was reacted in the presence of the Au/C catalyst, even if Pd/C is present ( Figure 5B). Following the hydrogen-borrowing mechanism in Figure 4, it sounds plausible that cyclohexylaniline 4 could be in equilibrium with the corresponding imine 8 and, since the latter is reluctant to further amine condensation, [20][21][22] there is an opportunity for further hydrolysis to give cyclohexanone 9. To check that, the intermediate N-cyclohexylideneaniline 8 was synthesized 23 and tested under reaction conditions with the Au/C catalyst ( Figure 5C).…”

A bifunctional palladium/acid solid catalyst performs the direct synthesis of cyclohexylanilines and dicyclohexylamines from nitrobenzenes

“…6 The most active and selective catalyst for this transformation is an organoruthenium (II) hydride complex (known as Shvo´s catalyst) reported by Beller and 40 coworkers. 7,8 This excellent homogeneous process and, to our knowledge, all the other catalytic systems reported to date operate at temperatures >120 ˚C. 6 In contrast, the reduction of nitrobenzene to aniline 2→3 and the subsequent reduction of aniline to cyclohexylamine 3 → 4 operate under milder 45 conditions.…”

C–N Coupling of nitrogen nucleophiles with aryl and heteroaryl bromides using aminoarenethiolato–copper(I) (pre-)catalyst

“…Same procedure as 2a starting from 2-bromomethylnaphthalene (5.50 g, 24.87 mmol) and dimethylamine (50 mL, excess), affording the product as a yellow oil (3.29 g, 17.76 mmol, 92% d 140. 5,136.2,133.6,133.5,130.7,129.0,127.4,136.7, 9, 136.7, 134.5, 133.2, 131.0, 129.6, 125.8, 125.5, 124.3, 1232.8 (Naphthyl C) 6, 137.5, 135.3, 133.8, 131.9, 131.1, 127.7, 126.2, 125.1 (Naphthyl C), 67.02 (CH 2 N), 56.7 (N(CH 2 ) 2 ), 23.8 ((CH 2 ) 2 ), 1.31 (SSi(CH 3 )). 8,135.9,134.5,134.3,133.6,131.1,130.1,127.5,126.4,125.4 (Naphthyl C) 3, 137.8, 136.4, 133.7, 133.2, 132.2, 128.4, 127.5, 126.9, 126.0 (Naphthyl C), 62.…”

“…Recently, a large number of elegant Pd-catalyzed C-N coupling reactions have been reported, 2 but the scope of these methods scarcely include the arylation of, for example, N-H heterocycles. 3 Besides the use of palladium and copper (vide infra), also other metals have recently been explored as catalyst for C-N bond forming reactions, e.g., catalysts based on cadmium, 4 ruthenium, 5 nickel, 6 or iron.…”