Copper(I)‐Catalyzed Reductive Cross‐Coupling of N ‐Tosylhydrazones with Amides: A Straightforward Method for the Construction of C( sp 3 )N Amide Bonds from Aldehydes

A method for the one‐pot synthesis of substituted amides from aldehydes and amides is presented. Namely, condensation of aldehydes with N ‐tosylhydrazide generated the N ‐tosylhydrazones which were then reductively cross‐coupled in situ with primary or secondary amides in the presence of a copper catalyst to afford secondary or tertiary amides, respectively. The reaction proceeded efficiently for a wide range of aldehydes and amides under the optimized conditions, i.e., 10 mol% of tetrakis(acetonitrile)copper(I) tetrafluoroborate [Cu(CH 3 CN) 4 BF 4 ], 1 mol% of tetra‐ n ‐butylammonium iodide [( n‐ Bu) 4 NI], and sodium hydroxide [NaOH] as base in tetrahydrofuran (THF) at 80 °C. As a result, the method provides a straightforward route for the synthesis of substituted amides from readily available aldehydes via a transition metal‐catalyzed C( sp 3 )N amide bond forming reaction.