Aza-Wittig reaction of (β-diazo-α,α-difluoroethyl)phosphonates with aldehydes for the synthesis of difluoromethylphosphonate-containing arylidene hydrazones

An aza-Wittig reaction of in situ generated difluoroalkyl diazo analog, (β-diazo-α,α-difluoroethyl)phosphonates, with aldehyde under mild conditions has been developed to afford difluoromethylphosphonate-containing arylidene hydrazones up to 99 % yields. The reaction was carried out under mild conditions with a broad substrate scope and was suitable for scale-up application. This reaction provides an efficient method for the facile construction of a series of difluoromethylphosphonate-containing arylidene hydrazones and is also a useful supplement to the transformation of (β-diazo-α,α-difluoroethyl)phosphonates.