Iron-catalyzed selective reduction of nitroarenes to anilines using organosilanes

Abstract

The iron-catalyzed reduction of aromatic nitro compounds to the corresponding anilines applying organosilanes is reported. In the presence of FeX(2)-R(3)P catalysts a series of nitroarenes is selectively reduced tolerating a wide range of functional groups.

Selective Reduction of Carboxylic Acid Derivatives by Catalytic Hydrosilylation

“…Notably, other reducible functional groups, such as cyano, nitro, ester, ether, and alcohol groups, as well as C = C double bonds, were not affected under these conditions. [36] During their studies on the iron-catalyzed reduction of amides, Nagashima and co-workers observed a selective catalytic reduction of nitroarenes to anilines with TMDS. Notably, this reduction proceeded preferentially in the presence of the amide group, which was not the case for catalysis by platinum or ruthenium compounds.…”

Straightforward Uranium‐Catalyzed Dehydration of Primary Amides to Nitriles

“…Significantly, the system UO 2 A C H T U N G T R E N N U N G (NO 3 ) 2 ·6H 2 O/MSTFA demonstrated excellent selectivity in presence of sensitive functional groups (for example, nitro and CÀC double bonds), whereas for other transition-metal/R 3 Si À H-based systems, side reactions can occur. [16] With respect to the reaction mechanism, we assume a similar pathway as proposed by Nagashima et al for ruthenium catalysts and Beller et al for iron catalysts (Scheme 1).…”

Phosphane‐Free Green Protocol for Selective Nitro Reduction with an Iron‐Based Catalyst

“…One of the major advantages of the present method is its tolerance towards -OCH 2 C 6 H 5 and -NHCH 2 C 6 H 5 groups, which were often either not studied or found to be affected by other methods (Table 3, entries 17 and 18). [20,21] Excellent yield and selectivity were observed for both these cases using Method C. Various heterocyclic nitro arenes were converted into the corresponding anilines without affecting the heterocyclic ring (Table 3, entries 20-23). In case of 1-nitronaphthalene, more than 99 % selectivity and yield were obtained (Table 3, entry 24).…”

“…Beller and co-workers carried out chemo-and regioselective reduction of aromatic nitro compounds by using FeBr 2 /P(cy) 3 with PhSiH 3 as a hydrogen source in toluene. [20] Although, both high selectivity and conversion were observed, the long reaction times and the use of toxic P(cy) 3 and toluene as solvent, limited the scope of the reaction. Herein, we report the first iron(II) salt/iron phthalocyanine (FePc) catalyzed reduction of nitroarenes to the corresponding anilines in a mixture of water and ethanol (1:1) (ethylene glycol in some cases) with hydrazine hydrate as hydrogen source.…”