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.