Isolable Phosphaalkenes Bearing 2,4,6-Trimethoxyphenyl and 2,6-Bis(trifluoromethyl)phenyl as P-Substituents.

The multistep synthesis and characterization of new P═C analogues of olefins from readily available starting materials is reported. Specifically, the phosphaalkenes TMOP-P═CPh2 (1a: TMOP = 2,4,6-trimethoxyphenyl) and ArF-P═CPh2 [1b: ArF = 2,6-bis(trifluoromethyl)phenyl] have been prepared, isolated, and characterized. In addition, synthetically challenging intermediates, such as the corresponding pyrophoric primary phosphines and bis(trimethylsilyl)phosphines, have been isolated and characterized. The title compounds, TMOP-P═CPh2 (1a) and ArF-P═CPh2 (1b), along with TMOP-PH2 (3a) have been characterized by X-ray crystallography. Importantly, the successful synthesis and isolation of phosphaalkenes 1a and 1b provides a foundation for future investigations of their polymerization, by analogy to the known polymerization of Mes-P═CPh2.