“On-water” reduction of α-keto amide by Hantzsch ester: A chemoselective catalyst- and additive-free way to α-hydroxy amide

Cobalt-Catalyzed Chemoselective Reduction of N-Heteroaryl Ketones with N,N-Dimethylformamide as a Hydride Source

“…The hydrolysis of DMF with Zn­(OAc) 2 ·2H 2 O yielded dimethylamine and formic acid, which underwent a Leuckart–Wallach type reaction with aldehydes and ketones to give N , N -dimethyl tertiary amines. As a part of our program to develop new reduction methods, , herein, we report a method for chemoselective transfer hydrogenation of 2-pyridine ketones and related N -heterocyclic compounds catalyzed by cobalt­(II) stearate using DMF as the hydride source (Scheme , c). Unlike conventional methods with regard to the reduction of carbonyl compounds with DMF leading to tertiary amines, , the present protocol provides functionalized alcohols with high efficiency.…”

Rongalite-Mediated Transition Metal- and Hydride-Free Chemoselective Reduction of α-Keto Esters and α-Keto Amides

“…Although many primeval methods are available for the synthesis of α-hydroxy amides, the chemoselective reduction of α-keto amides is one of the most straightforward methods in this category. Mainly three groups, viz ., Wu et al, Sekar et al, and Bhanage et al, have made significant contributions via (i) transfer hydrogenation using Hantzsch ester, i -PrOH/Ru-g-C 3 N 4 , HCOONa, i -PrOH/zirconium MOF, and DMF/NaOH/H 2 O system and (ii) catalysts such as Cu, TBAF, Cs 2 CO 3 , K 3 PO 4 , Ni, and NS-CeO 2 with the help of a hydride source (Scheme ). Although these methods give good results, they suffer from their own set of limitations such as high temperatures, long reaction times, and production of large amounts of silanol-based byproducts.…”