thereby increasing
the chemoselectivity and functional group tolerance in the
substrates. α-(Trialkylsilyl)phosphonates have been extensively
studied by Savignac et al.
15
and are mainly used as precursors of
vinylphosphonates through the Peterson olefination.
ever, to the best of our knowledge, only two reports were
dealing with the use of those reagents for the synthesis of
α‑substituted β‑ketophosphonates.
17,18
In one report, the
conjugate addition of organolithium reagents to diethyl1‑(trimethylsilyl)vinylphosphonate was achieved, and the
resulting lithiated phosphonate intermediate was trapped with
acyl chlorides to generate α-alkyl-β-ketophosphonates in good
yields. However, only unfunctionalized organolithium reagents
and acyl chlorides were used as partners.
17
The second report is
dealing with α-(trimethylsilyl)methylphosphonate 1, which
produces β-ketophosphonates with acyl fluorides as intermediates
for the HWE reaction.
18