Iodosobenzene bis(trifluoroacetate), bis(trifluoroacetoxy)iodobenzene, PIFA
Recent Literature
Oxidative deprotection of several dithiane-containing alkaloids in the presence
of bis(trifluoroacetoxy)iodobenzene and a nonchromatic
purification cleanly generates the corresponding ketoamines. The described procedure
is ideal for labile alkaloids.
F. F. Fleming, L. Funk, R. Altundas, Y. Tu, J. Org. Chem., 2001,
66, 6502 - 6504.
A metal-free esterification of a broad range of alkynes with alcohols in the
presence of phenyliodine bis(trifluoroacetate) produces esters in good yields
via carbon triple bond cleavage. The transformation proceeds via
hydroxyethanones and ethanediones as intermediates and exhibits a broad
substrate scope and good functional group tolerance.
Q. Jiang, A. Zhao, B. Xu, J. Jia, X. Liu, C. Guo, J. Org. Chem., 2014,
79, 2709-2715.
The use of phenyliodine(III) bis(trifluoroacetate) enables a facile and direct
oxidation of readily available β-ketoamides to provide vicinal tricarbonyl
amides in good yields. This approach is a valuable addition to the group of
traditional methods already available.
Y. Liu, Z. Zhang, Y. Wan, G. Zhang, Z. Li, J. Bi, N. Ma, T. Liu, Q. Liu, J. Org. Chem.,
2017, 82, 3901-3907.
Lewis bases catalyze vicinal dioxygenation of olefins with hypervalent iodine
reagents under mild conditions. The reaction tolerates various functional groups.
L. Pan, Z. Ke, Y.-Y. Yeung, Org. Lett., 2021, 23,
8174-8178.
An efficient, metal and base-free, chemoselective reaction of boronic acids with
cyanamidyl/arylcyanamidyl radicals provides primary aryl-, heteroaryl-, and
alkyl amines at ambient temperature within 1 h. The reaction is mediated by PIFA
and NBS.
N. Chatterjee, M. Arfeen, P. V. Bharatam, A. Goswami, J. Org. Chem.,
2016,
81, 5120-5127.
An oxidative deprotection of p-methoxy benzyl (PMB) ethers was
achieved using a nitroxyl radical catalyst with electron-withdrawing ester
groups adjacent to the nitroxyl group in the presence of 1 equiv of PIFA as
co-oxidant. The corresponding carbonyl compounds were obtained in the presence
of an excess of PIFA.
S. Hamada, K. Sugimoto, E. E. Elboray, T. Kawabata, T. Furuta,
Org. Lett., 2020, 22, 5486-5490.
A nitroxyl radical catalyzes an oxidative deprotection of benzyl groups in
the presence of phenyl iodonium bis(trifluoroacetate) at ambient temperature
with broad substrate scope, including substrates possessing
hydrogenation-sensitive functional groups. The catalytic system was also
effective for the direct synthesis of ketones and aldehydes from Bn ethers using
an excess of PIFA.
S. Hamada, M. Sumida, R. Yamazaki, Y. Kobayashi, T. Furuta, J. Org. Chem., 2023, 88,
12464-12473.
A nitroxyl radical catalyzes an oxidative deprotection of benzyl groups in
the presence of phenyl iodonium bis(trifluoroacetate) at ambient temperature
with broad substrate scope, including substrates possessing
hydrogenation-sensitive functional groups. The catalytic system was also
effective for the direct synthesis of ketones and aldehydes from Bn ethers using
an excess of PIFA.
S. Hamada, M. Sumida, R. Yamazaki, Y. Kobayashi, T. Furuta, J. Org. Chem., 2023, 88,
12464-12473.
A microwave-assisted, metal-free direct decarboxylative elimination of
arylacetic acids in the presence of PIFA as oxidant readily provides alkenes in
good yields.
S.-W. Wu, J.-L. Liu, F. Liu, Org. Lett.,
2016,
18, 1-3.
A new and convenient one-pot catalytic addition-elimination reaction converted a
range of (E)-3-butenoic acids into the corresponding butenolides in good
yields in the presence of 5 mol % diphenyl diselenide and [bis(trifluoroacetoxy)iodo]benzene
in acetonitrile.
D. M. Browne, O. Niyomura, T. Wirth, Org. Lett., 2007,
9, 3169-3171.
Desilylative acetoxylation of (trimethylsilyl)arenes can be performed in the
presence of 5 mol % of Pd(OAc)2 and PhI(OCOCF3)2
(1.5 equiv) in AcOH at 80°C for 17 h providing acetoxyarenes in very good yields.
The synthetic utility is demonstrated with a one-pot transformation of (trimethylsilyl)arenes
to phenols by successive acetoxylation and hydrolysis.
K. Gondo, J. Oyamada, T. Kitamura, Org. Lett.,
2015,
17, 4778-4781.
Fluorination of styrene derivatives with a reagent system composed of
μ-oxo-bis[trifluoroacetato(phenyl)iodine] or PhI(OCOCF3)2
and a pyridine·HF complex gave the corresponding (2,2-difluoroethyl)arenes in
good yields. Catalytic conditions using 4-iodotoluene as a catalyst and m-CPBA
as a terminal oxidant are possible.
T. Kitamura, K. Muta, J. Oyamada, J. Org. Chem.,
2015,
80, 10431-10436.
A highly regioselective intermolecular azidoamination of olefins under
metal-free conditions enables an operationally simple synthesis of 2-azidoimines
as versatile precursors to value-added vicinal unsymmetrical diamines. The
approach proceeds through two differentiated N-centered radicals.
Y. Xu, B. Wang, J. Wang, X. Zhou, J. Chen, X. Guo, G.-J. Deng, W. Shao, Org. Lett., 2023, 25,
8716-8721.
PIFA mediates a nitration of aryl amines in the presence of MeNO2 as
solvent and H2O as cosolvent via NO2 transfer. Using H2O
as the solvent, the C(sp2)-H
functionalization shifts to an α-C(sp3)-H functionalization (cyanation or oxygenation) of the α-C(sp3)-H of cyclic amines.
C. Mudithanapelli, L. P. Dhorma, M.-h. Kim,
Org. Lett., 2019, 21, 3098-3102.
The hypervalent iodine reagent PhI(OTf)2, generated in situ, has been
successfully utilized in a metal-free intramolecular oxidative cyclization of
N-styrylbenzamides. In remarkably short reaction times, the desired
2,5-disubstituted oxazoles were isolated in high yields.
C. Hempel, B. J. Nachtsheim, Synlett, 2013, 24,
2119-2123.
A mild, oxidative cycloisomerization of cis-enynols using a combination
of a hypervalent iodine(III) reagent, molecular iodine, and a base offers an
efficient synthesis of 2-acyl furans with diverse substitution patterns in a
regioselective manner. A mechanistic proposal for these transformations
involving alkyne activation by trifluoroacetylhypoiodite generated in situ is
presented.
X. Du, H. Chen, Y. Chen, J. Chen, Y. Liu, Synlett, 2011,
1010-1014.
Various 5-aryl-2-methyltetrazoles and 5-aryl-2-benzyltetrazoles were directly
prepared in good yields under transition metal-free and mild conditions by the
reaction of aromatic aldehydes with methylhydrazine and benzylhydrazine,
followed by treatment with di-tert-butyl azodicarboxylate and [bis(trifluoroacetoxy)iodo]benzene
in a mixture of dichloromethane and 2,2,2-trifluoroethanol at room temperature.
T. Imai, R. Harigae, K. Moriyama, H. Togo, J. Org. Chem.,
2016,
81, 3975-3980.
An intramolecular oxidative S-N bond formation of imidoyl thioureas mediated by
phenyliodine(III) bis(trifluoroacetate) enables an efficient, metal-free
synthesis of 3-substituted-5-arylamino-1,2,4-thiadiazoles. The protocol offers
broad substrate scope, very short reaction times and very good yields.
A. Mariappan, K. Rajaguru, N. M. Chola, S. Muthusubramanian, N. Bhuvanesh, J. Org. Chem.,
2016, 81, 6573-6579.
PIFA mediates an oxidative cyclization of 2-alkenyl anilines, which are prepared
by cross-coupling of the corresponding o-bromoanilines. This convenient
synthesis of N-H indoles enables regiospecific installations of alkyl and
aryl substituents.
J. H. Kim, S. A. Lee, T. S. Jeon, J. K. Cha, Y. G. Kim, Synlett, 2023,
34,
1719-1722.
The use of PIFA {[bis(trifluoroacetoxy)iodo]benzene} or quinones enables a
cyclization of 2-vinylanilines to provide various indoles under mild conditions
in good yields.
M. Wu, R. Yan,
Synlett, 2017, 28, 729-733.
Various N-arylated and N-alkylated indoles and pyrrole-fused aromatic compounds
were synthesized by a phenyliodine bis(trifluoroacetate) (PIFA)-mediated
intramolecular cyclization.
Y. Du, R. Liu, G. Linn, K. Zhao, Org. Lett., 2006,
8, 5919-5922.
The hypervalent iodine reagent PIFA promotes the efficient intramolecular
electrophilic cyclization of easily accessible alkynylamides and alkynyl
carboxylic acids, leading to pyrrolidinone and lactone skeletons, respectively.
A synthetic study and a mechanistic proposal for these transformations are
presented.
I. Tellitu, S. Serna, m. T. Herrero, I. Moreno, E. Domínguez, R. SanMartin, J. Org. Chem., 2007,
72, 1526-1529.
A general and efficient reaction of readily available N-methyl-N-phenylcinnamamides
with phenyliodine bis(trifluoroacetate) (PIFA) in the presence of Lewis acids
provides various 3-arylquinolin-2-one compounds in good yields. This novel
approach features not only metal-free oxidative C(sp2)-C(sp2)
bond formation but also an exclusive 1,2-aryl migration.
L. Liu, H. Lu, H. Wang, C. Yang, X. Zhang, D. Zhang-Negrerie, Y. Du, K. Zhao, Org. Lett., 2013,
15, 2903-2909.
The use of [bis(trifluoroacetoxy)iodo]benzene as stoichiometric oxidant and
2,3-dichloro-5,6-dicyano-1,4-benzoquinone as organocatalyst enables a convenient
oxidation of isochromans. A further reaction with grignard reagents or amides
affords the corresponding isochroman derivatives.
W. Muramatsu, K. Nakano, Org. Lett., 2014,
16, 2042-2045.
The biologically important 1,2,4-triazolo[1,5-a]pyridines were readily
synthesized from N-(pyridin-2-yl)benzimidamides via PIFA-mediated intramolecular annulation via a direct metal-free
oxidative N-N bond formation in short reaction times and high yields.
. Zheng, S. Ma, L. Tang, D. Zhang-Negrerie, Y. Du, K. Zhao, J. Org. Chem., 2014,
79, 4687-4693.
A facile and effective alkoxylation of quinoxalin-2(1H)-ones with
primary or secondary alcohols via cross-dehydrogenative coupling under
catalyst-free conditions provides 3-alkoxylquinoxalin-2(1H)-ones in very
good yields in the presence of PhI(OTFA)2 as oxidant.
Q. Yang, X. Han, J. Zhao, H.-Y. Zhang, Y. Zhang, J. Org. Chem., 2019,
84, 11417-11424.
A low-temperature, protecting-group-free oxidation of 2-substituted anilines
with PIFA in the presence of an acid generates an electrophilic N-aryl nitrenoid intermediate
that can engage in C-NAr bond formation to construct functionalized N-heterocycles,
such as spirocyclic-
or bicyclic 3H-indoles or benzazepinones.
T. Deng, W. Mazumdar, R. L. Ford, N. Jana, R. Izar, D. J. Wink, T. G. Driver, J. Am. Chem. Soc.,
2020, 142, 4456-4463.
