Reductive amidation of nitroarenes: a practical approach for the amidation of natural products

Reductive N-Alkylation of Nitroarenes: A Green Approach for the N-Alkylation of Natural Products

“…The regiochemistry of the nitro group in 3 was assigned on the basis of the strong HMBC correlations of H-5 ( δ H 7.91) to C-4a ( δ C 131.4) and C-4b ( δ C 129.1). Nitration of harmane ( 6 ), 5 a β -carboline alkaloid, with sodium nitrite gave two nitro products: 8-nitroharmane ( 7 ) and 6-nitroharmane ( 8 ). Recently, several β -carboline related alkaloids identified as prototypes to potent and orally efficient antimalarial leads were synthesized via similar reductive amination chemistry.…”

“…4b This instability was the inspiration for development of our one-pot reductive amidation method using Zn/HOAc as the reducing system and acyl chloride/Et 3 N as the acylating agent in DMF. 5 The same challenges occurred when attempting to N -alkylate aminomanzamines by direct and reductive alkylation methods. As a result, we explored the utility of our previously used reducing system (Zn/HOAc) to accomplish an effective one-pot reductive N -alkylation of nitroarenes with carbonyl compounds as the alkyl source.…”

Direct hydrogenation and one-pot reductive amidation of nitro compounds over Pd/ZnO nanoparticles as a recyclable and heterogeneous catalyst

“…for C 8 H 11 N: C,79.29;H,9.15;N,11.56. Found: C,78.90;H,9.10,N,11.45. 7, 135.7, 134.9, 128.5, 126.5, 125.7, 124.4, 24.2, 23.4, 13.9; Anal.…”

“…Therefore, one-pot reactions and direct amidation of carboxylic acids have been developed as economical, environmentally friendly, and greener processes with the extraordinarily high atom economy in industry [6], and organic chemistry [7]. However, up to now, a few catalytic systems for the direct conversion of nitroarenes to amides have been developed, such as platinum nanowires [3k], platinum complex [8], peroxide-Mediate [9], Indium [10], zinc and acetic acid [11], palladium [12], Pt/ZrO 2 [3j], and potassium thioacetate-mediated [13]. Although, these methods were shown some advantages of direct amidation of nitro groups of the corresponding products but some of them were laborious (the problem for disposal a large amount of metal salts that generated during the reaction, and using the difficulty in producing isolation from the metal sludge formed during the reaction).…”

The immobilized Ni(II)‐thiourea complex on silica‐layered copper ferrite: A novel and reusable nanocatalyst for one‐pot reductive‐acetylation of nitroarenes

“…Acetamides have been widely used as key intermediates in many biologically active compounds and a number of drug candidates . Generally, acetamides can be prepared from nitro compounds in a two‐step procedure including reduction of nitro compounds to amines and consequently acetylation of the prepared amines with an acetylating agent.…”