Categories: C-I Bond Formation >
Synthesis of α-iodocarboxylic acids and derivatives
Recent Literature
By rendering the α-position of amides electrophilic through a mild and
chemoselective umpolung transformation, a broad range of widely available
oxygen, nitrogen, sulfur, and halogen nucleophiles can be used to generate
α-functionalized amides.
C. R. Gonçalves, M. Lemmerer, C. J. Teskey, P. Adler,
D. Kaiser, B. Maryasin, L. González, N. Maulide, J. Am. Chem. Soc.,
2019, 141, 18437-18443.
Primary, secondary, tertiary, benzylic, propargylic and α-functionalized
alkyl fluorides react in chlorinated or aromatic solvents at room temperature or
upon heating with inexpensive lithium iodide to give the corresponding iodides
in very good yields. The reaction is selective for aliphatic monofluorides and
can be coupled with in situ nucleophilic iodide replacements.
K. Balaraman, S. Kyriazakos, R. Palmer, F. Y. Thanzeel, C. Wolf, Synthesis, 2022, 54,
4320-4328.
γ-Hydroxy-α,β-acetylenic esters are used as precursors for the preparation of γ-hydroxy-α,β-alkenoic esters
by means of trans-selective additions of two hydrogen atoms or one hydrogen atom
and one iodine atom across the triple bonds. These methods allow the preparation
of β-substituted and α,β-disubstituted alkenoic esters in highly stereoselective
manners.
C. T. Meta, K. Koide, Org. Lett., 2004, 6, 1785-1787.
Related
Treatment of widely available isocyanates with monohalolithium and dihalolithium
carbenoids provides α-halo- and α,α-dihaloacetamide derivatives. While
monohalolithium carbenoids can be prepared by a smooth lithium-halogen exchange,
the preparation of the corresponding dihalo compounds proved to be highly
dependent on the base used to realize the deprotonation, with lithium
2,2,6,6-tetramethylpiperidine emerging as optimal.
V. Pace, L. Castoldi, A. D. Mamuye, W. Holzer, Synthesis, 2014, 46,
2897-2909.