Categories: C-F Bond Formation >
Synthesis of fluoroarenes
Name Reactions
Recent Literature
Drawbacks associated with the classic Balz-Schiemann reaction are eliminated
in a series of examples by conducting fluorodediazoniation in ionic liquid
solvents.
K. K. Laali, V. J. Gettwert, Journal of Fluorine Chemistry, 2001,
107, 31-34.
A palladium-catalyzed synthesis of aryl fluorides from arylboronic acid
derivatives is operationally simple and amenable to multigram-scale synthesis.
Evaluation of the reaction mechanism suggests a single-electron-transfer pathway
that involves a Pd(III) intermediate.
A. R. Mazzotti, M. G. Campbell, P. Tang, J. M. Murphy, T. Ritter, J. Am. Chem. Soc., 2013,
135, 14012-14015.
Electron-rich aryl boronic acids or pinacol esters were converted in good yields
and fast reactions to the corresponding aryl fluorides using readily obtainable
solutions of AcOF. In reactions with aryl boronic acids containing EWG at the
para position, fluorination ortho to the boronic acid is in competition with an
ipso substitution. With EWG meta to the boronic acid, substitution ipso to the
boron moiety takes place in good yields.
I. Vints, J. Gatenyo, S. Rozen, J. Org. Chem., 2013,
78, 11794-11795.
A new biaryl monophosphine ligand enables a room-temperature Pd-catalyzed
fluorination of various activated (hetero)aryl triflates and bromides with high
regioselectivity. Analysis of the solid-state structures of several Pd(II)
complexes, as well as density functional theory (DFT) calculations help to
explain the enhanced reactivity.
A. C. Sather, H. G. Lee, V. Y. De La Rosa, Y. Yang, P. Müller, S. L. Buchwald, J. Am. Chem. Soc., 2015,
137, 13433-13438.
Functionalized aryl- or heteroarylmagnesium reagents, prepared from the
corresponding bromides or iodides using halogen-magnesium exchange or direct
magnesium insertion in the presence of lithium chloride, reacted smoothly with
N-fluorobenzenesulfonimide to give the corresponding aromatic fluorides
in good yields.
S. Yamada, P. Knochel, Synthesis, 2010,
2490-2494.
A low-barrier photoinduced ligand to metal charge transfer (LMCT) enables a
radical decarboxylative carbometalation strategy. Formation of a putative high-valent
arylcopper(III) complex facilitates reductive eliminations to
occur. This approach is suitable to address a previously unrealized general
decarboxylative fluorination of benzoic acids at low temperature.
P. Xu, P. López-Rojas, T. Ritter, J. Am. Chem. Soc.,
2021, 143, 5349-5354.
A LiBF4-promoted aromatic fluorodetriazenation of
3,3-dimethyl-1-aryltriazenes proceeds smoothly within 2 h in the absence of
protic or strong Lewis acids. This efficient and mild fluorination method
tolerates a wide range of functional groups and affords aryl fluoride products
in good yields.
H. Zhang, J. Wu, X. Zhang, M. Fan, J. Org. Chem., 2023, 88,
12826-12834.
A mild copper-mediated fluorination of aryl stannanes and aryl trifluoroborates
with N-fluoro-2,4,6-trimethylpyridinium triflate (NFTPT) demonstrates
broad substrate scope and functional group tolerance, and does not require the
use of any noble metal additives. The reaction is proposed to proceed via an
arylcopper(III) fluoride intermediate.
Y. Ye, M. S. Sanford, J. Am. Chem. Soc., 2013,
135, 4648-4651.
A mild Cu-catalyzed nucleophilic fluorination of unsymmetrical diaryliodonium
salts with KF preferentially fluorinates the smaller aromatic ligand on
iodine(III). The reaction exhibits a broad substrate scope and proceeds with
high chemoselectivity and functional group tolerance.
N. Ichiishi, A. J. Canty, B. F. Yates, M. S. Sanford, Org. Lett., 2013,
15, 5134-5137.
PhenoFluorMix, a mixture of N,N'-1,3-bis(2,6-diisopropylphenyl)chloroimidazolium
chloride and CsF, overcomes the challenges associated with hydrolysis of
PhenoFluor. PhenoFluorMix does not hydrolyze, is readily available on decagram
scale, and is storable in air. The reagent can be used for the deoxyfluorination
of various phenols and heterocycles.
T. Fujimoto, T. Ritter, Org. Lett.,
2015,
17, 544-547.
An operationally simple ipso fluorination of phenols with a new
deoxyfluorination reagent can be used conveniently from miligram to multigram
scale. Whereas hydrogen bonding is undesirable on conventional nucleophilic
fluorination chemistry because it reduces the nucleophilicity of fluoride,
hydrogen bonding appears to be crucial for this fluorination method.
P. Tang, W. Wang, T. Ritter, J. Am. Chem. Soc., 2011,
133, 11482-11484.
An air-stable and moisture-insensitive
2-chloro-1,3-bis(2,6-diisopropylphenyl)imidazolium poly[hydrogen fluoride] salt
is capable of converting electron-deficient phenols or aryl silyl ethers into
the corresponding aryl fluorides in the presence of DBU as a base, with good to
excellent yields and high tolerance to functional groups.
J. Jelen, G. Tavčar, Org. Lett., 2023, 25,
3649-3653.