The 3-chloroperoxybenzoic acid oxidation of dimethylhydrazones of aromatic aldehydes gives the corresponding nitriles in good yields. Two further examples of the same oxidative transformation of cinnamaldehyde and of hexanal are also given. Except for hexanal hydrazone, all other aldehyde hydrazones can also be efficiently converted into nitriles by treatment with methanolic 30 % hydrogen peroxide in the presence of catalytic amounts of selenium dioxide or, preferentially, 2-nitrobenzeneseleninic acid.
A palladium‐catalyzed C(sp2)−H difluoromethylation of aldehyde‐derived hydrazones using bromodifluoromethylated compounds to afford the corresponding functionalized difluoromethylketone hydrazones has been established. It is proposed that a radical/SET mechanism proceeding via a difluoroalkyl radical may be involved in the catalytic cycle. Applications of the methodology to the synthesis of α,α‐difluoro‐β‐ketoesters
Improved Efficient Conversion of Aldehydes to Nitriles <i>via</i> Their N, N-Dimethyl Hydrazones
作者:Ahmed Kamal、M. Arifuddin、N. VenugopalRao
DOI:10.1080/00397919808004513
日期:1998.12
Aldehyde N,N-dimethylhydrazones undergoes facile oxidative cleavage to nitriles on reaction with DIMS and K2CO3 in quantitative yields. Nitriles can also be easily obtained in high yields in a 'one-pot' process starting from the corresponding aldehydes.