ChemInform Abstract: Hydrophosphorylation of Substituted Alkynes with Phosphinous Acids.

Radical Hydrophosphorylation of Alkynes with R2P(O)H Generating Alkenylphosphine Oxides: Scope and Limitations

“…Radical-initiated additions (especially those of the photoinduced ones) of P­(O)H compounds to alkynes can avoid the above-mentioned metal-contamination problem. From the literature, it is expected that both a radical initiator (including oxygen) and light should possibly induce this kind of radical hydrophosphorylation . However, such studies are rather limited, and the scope and limitations of such a radical hydrophosphorylation are not clear.…”

“…A possible mechanism for this photoinduced hydrophosphorylation is shown in Scheme . The phosphoryl radical generated under light adds to alkynes to generate alkenyl radicals which exist in trans I and cis II forms with the former being more stable but less reactive and the latter being more reactive but less stable . Subsequent reactions of I and II with Ph 2 P­(O)H give the corresponding alkenylphosphine oxides.…”