Formic Acid or Formate Derivatives as the In Situ Hydrogen Source in Au‐Catalyzed Reduction of para‐Chloronitrobenzene

Abstract

Formic acid and formate derivatives as hydrogen source on the hydrogenation of para‐chloronitrobenzene (p‐CNB) over supported gold catalysts were investigated. The hydrogenation activity in various formate derivatives followed the order: HCOOH < HCOONa < HCOOK < HCOONH4, which was in accordance with the decrement of electronegativity of cation species in formate derivatives. Moreover, in the case of HCOONH4 as hydrogen source, the p‐CNB conversion could enhance ten‐fold as the hydrogen source of H2 at 60 oC. This promotion effect was also found in other supported Au catalysts. These results provide a general alternative hydrogen source to replace conventional H2 as reducing agent for fine chemical processes.

Catalyst‐ and Additive‐Free Chemoselective Transfer Hydrogenation of α‐Keto Amides to α‐Hydroxy Amides by Sodium Formate

“…Although strongly electron‐withdrawing groups, CF 3 and CN, were well tolerated in this protocol, the substrate with a NO 2 group produced a complex mixture, which might be caused by the potential reduction of the NO 2 group into other functionalities under the current reaction conditions (entries 11–13). [19a] As expected, the replacement of phenyl group with naphthyl group did not cause any influence on the yield (entry 14). Furthermore, the substrate with an aliphatic amide moiety was investigated as well.…”

“…Formate derivatives are regarded as an important class of hydrogen storage today, because of their decomposition into H 2 and CO 2 with high efficiency . The hydrogenation of unsaturated functional groups using formate derivatives as a hydrogen source has been extensively investigated, among which transition metal‐catalyzed transfer hydrogenation of the ketone functionality is a subject of current interest .…”

Recent Advances in Catalytic Transfer Hydrogenation with Formic Acid over Heterogeneous Transition Metal Catalysts

“…In this respect, during the reductive annealing, the reducible oxide supports (e.g., TiO 2 , Fe 3 O 4 , and CeO 2 ) can be partially reduced to the structure with a nonstoichiometric oxygen concentration, facilitating electron transfer between the metal NPs and oxide supports. 33,84,107,108 For example, group VIII metals (e.g., Au) are easy to sinter under harsh reaction conditions because of their high surface energy. It was reported that with the formation of metal−support interaction, the Au NPs with 2.2 nm were dispersed on rutile TiO 2 , making the Au NPs highly stable and active in CTH of quinolines and nitro compounds with FA.…”

“…because of its excellent acid-tolerance under t h e h a r s h c o n d i t i o n s r e q u i r e d i n C T H p r o cess. 38,61,62,64,65,67,70,108 GVL. Among those supported on carbon, SiO 2 , Al 2 O 3, ZrO 2 , TiO 2 , SnO 2 , Nb 2 O 5 , ZrO 2 -supported catalysts exhibited the highest activity, producing GVL at 77% yield at 150 °C for a 5 h reaction, ascribed to the beneficial role of surface hydroxyls on ZrO 2 .…”

“…Aniline is an important feedstock for the synthesis of a variety of chemicals . Generally, aromatic amines can be synthesized through catalytic reduction or hydrogenation of corresponding nitroarenes such as nitrobenzene (NB). − Among all noble metal catalysts used for CTH of nitroarenes with FA (e.g., Pd, Pt, Au), ,,,− Pd-based catalysts are dominant. Li et al found that Pd/CN-PC catalyst obtained facilely with a mild photochemical method achieved an extremely high TOF value (1183 mol­(NB) mol –1 Pd h –1 ) for CTH of nitrobenzene at 298 K, surpassing the bench-mark heterogeneous catalysts for all catalytic reactions using FA or formates as hydrogen source.…”