Beilstein J. Org. Chem.2018,14, 3018–3024, doi:10.3762/bjoc.14.281
fission may also be used to generate different metal derivatives of the nucleofugal anions as equilibrium components. Fluoride-catalyzed, metal-free desilylation admitted carbonyl addition but blocked the retro-addition.
Keywords: alkoxide fission; desilylation; fragmentation; retro-addition; reversible
and a carbonyl compound (R1)2C=O. Such a C–C fission (retro-addition reaction) can occur already near room temperature (rt) if the nucleofugal carbanion proves to be an electronically stabilized N≡C–CH2– [1] or allylic [2] species or a short-lived equilibrium component [3].
A cleavable alkoxide A1M1
blocked by FSiMe3 and hence unsuitable for an analysis of the retro-addition reaction (see Supporting Information File 1).
Conclusion
(i) The nucleofugal carbanion (α-deprotonated 1) can escape with surprising ease from alkoxides, perhaps with some assistance by a metal cation if present. Conversely
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Graphical Abstract
Scheme 1:
The nucleofugal carbanion unit C escapes from the alkoxides A1M1 or A1M2 (M = metal), generating th...