Solid-State Structure of a Bromo(difluoromethylenephosphonato)cuprate – a Key Intermediate for the Synthesis of α,α-Difluoromethylenephosphonates

Many approaches to introduce the CF2P(O)(OR)2 unit into organic molecules make use of Cu(I) catalysed couplings between organic halides and BrZnCF2P(O)(OR)2. Despite the great importance of this process for the synthesis of α,α-difluoromethylenephosphonates the constitution and molecular structures of the organozinc precursor and the catalytically relevant copper/zinc complex are still unknown. Here we report on the isolation of both species and on the structural elucidation by single crystal x-ray diffraction in addition to spectroscopic characteristics. First orienting experiments on the stability of the cuprate reagent in solution at room temperature as well as the reactivity towards allyl bromides were subsequently performed.