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The Catalytic N-heterocyclization of aminoarenes and dinitroarenes using aliphatic n-C3–C5 aldehydes was carried out at 180 °C under the pressure of carbon monoxide (70 atm at room temperature) in the presence of RhCl(PPh3)3 and PdCl2 as a binary catalyst system. The reaction of p-nitroaniline with propanal, butanal, and pentanal gave 3,8-diethyl-2,9-dimethyl-4,7-phenanthroline, 2,9-diethyl-3,8-dipropyl-4,7-phenanthroline, and 3,8-dibutyl-2,9-dipropyl-4,7-phenantroline in 43, 57, and 54% yields respectively. On the other hand, m-nitroaniline and o-nitroaniline gave 1,7-phenanthroline and imidazole derivatives in rather low yields (21 and 24%) under the reaction conditions employed.

Carbonyl compounds were hydrogenated to the corresponding alcohols in excellent yields using formic acid with a ruthenium complex at 125 °C for 3 h. 2-Propanone was reduced to 2-propanol by RuCl2(PPh3)3–HCOOH system in 94% yield with 98% selectivity. 3-Pentanone, cyclohexanone, acetophenone, and propiophenone were hydrogenated to the corresponding alcohols in 86, 78, 84, and 86% yields respectively. The ketone having the bulkier alkyl groups showed lower reactivity. The catalytic activity was found to decrease in the order RuCl2(PPh3)3, RuHCl(PPh3)3, RuHCl(CO)(PPh3)3, and RuH2(PPh3)4.

An equimolar mixture of a ketone and formic acid was heated without solvent at 125°C for 3 h in the presence of a catalytic amount of dichlorotris(triphenylphosphine)ruthenium(II) to give the corresponding secondary alcohols in excellent yields.

Nitroarenes are reductively converted into quinoline derivatives with aliphatic alcohols in the presence of a catalytic amount of ruthenium compound at 180 °C. Ruthenium(III) chloride is the most effective catalyst. The reaction of nitrobenzene with 1-propanol and 1-butanol gave 2-ethyl-3-methylquinoline and 3-ethyl-2-propylquinoline in 65 and 70% yields respectively. p-Methoxynitrobenzene gave 3-ethyl-6-methoxy-2-propylquinoline in 70% yield with 1-butanol. The reaction appears to include the redox reaction between the nitroarenes and the alcohols, that is, a catalytic hydrogen transfer reaction which generates the aminoarenes and aldehydes. Thus, the alcohol plays roles as both a reductant and an aldehyde precursor.

Amides reacted with primary alcohols in the presence of a catalytic amount of RuCl2(PPh3)3 at 180 °C to give the corresponding N-monoalkyl amides in fairly good yields. Thus, benzamide reacted with 1-octanol to give N-octylbenzamide in 76% yield with excellent product selectivity. Little esterification of amides with alcohols occurred and selectivity to the N-alkylation was high. Most of the amides gave N-monoalkyl amides but no N,N-dialkyl amides. But formamide reacted with 1-butanol to give N,N-dibutylformamide, as well as N-butylformamide, in low yield. RuCl2(PPh3)3 was the most effective catalyst for this reaction and RuHCl(PPh3)3 also had some catalytic activity.

Dichlorobis(triphenylphosphine) platinum(II) shows good catalytic activity for the reductive N-carbonylation of dinitroarenes in ethanol in the presence of a Lewis acid and triethylamine. From 2,4-dinitrotoluene, diethyl 4-methyl-1,3-phenylenebiscarbamate is obtained in 50% yield at 190°C under carbon monoxide pressure of 60 kg cm−2.

The platium catalyst combined with triphenylphosphine, tin(IV) chloride, and triethylamine showed high activity for the reductive N-carbonylation of nitroarene in ethanol at 180 °C under carbon monoxide of 60 kg cm−2. From nitrobenzene, ethyl phenylcarbamate was obtained in 83% yield. Iron(III) chloride, aluminum chloride and titanium(IV) chloride could be used as Lewis acids in place of tin(IV) chloride. Various nitroarenes were transformed into corresponding carbamate in moderate to excellent yields with the platinum catalyst.

Die primaren Amine (I) ergeben bei der Behandlung mit Platinkomplexen und Zinndichlorid die sekundaren Amine (ll).