PAPER
Syntheses of Symmetrical Diaryliodonium Salts
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corresponding iodonium bromides were isolated in higher crude
yields, viz. 80% and 75% (Table 1).
(5) Hickey, D. M. B.; Lesson, P. D.; Novelli, R.; Shah, V. P.;
Burpitt, B. E.; Crawford, L. P.; Davies, B. J.; Mitchell, M.
B.; Pancholi, K. D.; Tuddenham, D.; Lewis, N. J.; O’Farrell,
C. J. Chem. Soc., Perkin Trans. 1 1988, 3103; see Table 2
therein and its explanation on p 3106.
Symmetrical Diaryliodonium Bromides from Arenes; General
Procedure Modified from the Literature6 (Table 2)
Powdered I2 (0.72 g, 2.84 mmol; 0% excess) and NaIO4 (0.92 g,
4.30 mmol; 0% excess) were suspended in stirred concd H2SO4 (10
mL), and the vigorous stirring was continued at 70–75 °C for 1 h.
Next, Ac2O (0–10 mL, see Table 2) was slowly added dropwise,
with stirring, to the cooled suspension of yellow (IO)2SO4 (ca. 5
mmol). Arene (26 mmol; 30% excess) was added portionwise or
dropwise, with stirring, and the stirring was continued at r.t. for 20
h [only for benzene: the stirring was continued firstly at r.t. for 2 h,
and next at 50–55 °C for 1 h]. The final mixtures were poured into
stirred ice-H2O (300 g), and the following workups were the same
as those in the former procedure. The air-dried diaryliodonium bro-
mides were obtained in 22–70% crude yields. Small samples of the
crude bromides were quickly recrystallized from appropriate sol-
vents (Table 2) to afford the purified analytical samples. Note. Ani-
sole and thiophene were oxidized under the given reaction
conditions to form some unidentified tarry products, while 1,4-xy-
lene gave only a trace amount of the expected iodonium bromide.
(6) Beringer, F. M.; Falk, R. A.; Karniol, M.; Lillien, I.;
Masullo, G.; Mausner, M.; Sommer, E. J. Am. Chem. Soc.
1959, 81, 342.
(7) (a) Hossain, D.; Ikegami, Y.; Kitamura, T. J. Org. Chem.
2006, 71, 9903; which gives references in the literature to all
previous methods for the preparation of diaryliodonium
triflates. (b) Hossain, D.; Kitamura, T. Bull. Chem. Soc. Jpn.
2007, 80, 2213.
(8) For a review in Polish, see: Krassowska-Swiebodzka, B.;
Rudzki, P. Biul. Wydz. Farm. AMW 2004, 1;
0401Krassowska/Ojodylar.html.
(9) (a) Beringer, F. M.; Nathan, R. A. J. Org. Chem. 1969, 34,
685. (b) Beringer, F. M.; Nathan, R. A. J. Org. Chem. 1970,
35, 2095. (c) Gronowitz, S.; Holm, B. Synth. Commun.
1974, 4, 63.
(10) Frohn, H. J. unpublished results related in ref 2c, pp 215-
217.
Pure Symmetrical Diaryliodonium Tetrafluoroborates; Gener-
al Procedure (Table 3)
(11) Cornforth, J.; Ridley, D. D.; Sierakowski, A. F.; Uguen, D.;
Wallace, T. W.; Hitchcock, P. B. J. Chem. Soc., Perkin
Trans. 1 1982, 2317.
(12) Tyrra, W.; Butler, H.; Naumann, D. J. Fluorine Chem. 1993,
60, 79.
Powdered crude diaryliodonium bromide (5 mmol) was suspended
in acetone (15 mL), and next 40% aq HBF4 (1 mL, ca. 6 mmol
HBF4) and 30% aq H2O2 (0.75 mL, ca. 7.3 mmol H2O2) were sub-
sequently added slowly with stirring. The stirred suspension was re-
fluxed until the suspended bromide fully dissolved, and the boil was
continued for a further 15 min. The solvent was distilled off in a ro-
tory evaporator. The semisolid residue was triturated with Et2O (15
mL). The solid precipitate was collected by filtration, washed with
Et2O, dried preliminarily by the suction, air-dried in the dark, and
recrystallized from appropriate solvent (Table 3) to give the respec-
tive pure diaryliodonium tetrafluoroborate in the yield given in
Table 3. Note: Our easy method of oxidative anion metatheses is
also suitable for both inorganic ionic halides29 as well as for organic
tetraalkylammonium halides.18b
(13) (a) Lulinski, P.; Skulski, L. Bull. Chem. Soc. Jpn. 2000, 73,
951. (b) Kraszkiewicz, L.; Sosnowski, M.; Skulski, L.
Tetrahedron 2004, 60, 9113. (c) Kraszkiewicz, L.;
Sosnowski, M.; Skulski, L. Synthesis 2006, 1195.
(14) Lulinski, P.; Sosnowski, M.; Skulski, L. Molecules 2005, 10,
(15) Kasumov, T. M.; Koz‘min, A. S.; Zefirov, N. S. Russ. Chem.
Rev. 1997, 66, 843; Usp. Khim. 1997, 66, 936.
(16) (a) Chrétien, M. P. Ann. Chim. Phys. 1898, 15, 358. (b) All
former methods for preparing iodosyl sulfate are related in
ref 15, p 942, as well as in the earlier paper: Masson, I.;
Argument, C. J. Chem. Soc. 1938, 1702. (c) Concerning
Scheme 9: for more information on hygroscopic and easily
hydrolyzable iodylbenzene sulfate, PhIO2·H2SO4 (mp 127
°C), see: Masson, I.; Race, E.; Pounder, F. E. J. Chem. Soc.
1935, 1669.
(17) (a) Beringer, F. M.; Briedley, A.; Drexler, M.; Gindler, E.
M.; Lumpkin, C. C. J. Am. Chem. Soc. 1953, 75, 2708.
(b) Beringer, F. M.; Falk, R. A. J. Chem. Soc. 1964, 4442.
(c) Caserio, M. C.; Glusker, D. L.; Roberts, J. D. J. Am.
Chem. Soc. 1959, 81, 336.
(18) (a) Kazmierczak, P.; Skulski, L. Synthesis 1995, 1027.
(b) Kazmierczak, P.; Skulski, L. Bull. Chem. Soc. Jpn. 1997,
70, 219.
References
(1) These results were presented in part at the 9th International
Electronic Conference on Synthetic Organic Chemistry
(ECSOC-9), November 1–30th, 2005; Paper A022; see
Chem. Abstr. 2007, 147, 30753.
(2) For reviews on aromatic iodonium salts, see: (a) Olah, G.
A. Halonium Ions; Wiley: New York, 1975. (b) Koser, G.
F. In The Chemistry of Functional Groups, Suppl. D; Patai,
S.; Rappoport, Z., Eds.; Wiley: Chichester, 1983, Chap. 25.
(c) Varvoglis, A. The Organic Chemistry of
molecules/papers/51201331.pdf.
Polycoordinated Iodine; VCH: Weinheim, 1992. (d) Koser,
G. F. In The Chemistry of Halides, Pseudo-Halides and
Azides, Suppl. D2; Patai, S.; Rappoport, Z., Eds.; Wiley-
Interscience: Chichester, 1995, Chap. 21. (e) Stang, P. J.;
Zhdankin, V. V. Chem. Rev. 1996, 96, 1123. (f) Varvoglis,
A. Hypervalent Iodine in Organic Synthesis; Academic
Press: San Diego, 1997. (g) Chemistry of Hypervalent
Compounds; Akiba, K., Ed.; Wiley-VCH: New York, 1999,
Chap. 11 and 12. (h) Zhdankin V. V., Stang P. J.; Chem.
Rev.; 2002, 102: 2523. (i) Hypervalent Iodine Chemistry, In
Topics in Current Chemistry, Vol. 224; Wirth, T., Ed.;
Springer: Berlin, 2003. (j) Stang, P. J. J. Org. Chem. 2003,
68, 2997.
(20) Kryska, A.; Skulski, L. Molecules 2001, 6, 875;
(21) (a) Lulinski, P. Ph.D. Thesis; Warsaw Medical University:
Poland, 2002. (b) Sosnowski, M. Ph.D. Thesis; Warsaw
Medical University: Poland, 2005. (c) Zielinska, A. Ph.D.
Thesis; Warsaw Medical University: Poland, 2006. (d)
Kraszkiewicz, L. Ph.D. Thesis, Warsaw Medical University:
Poland, in preparation.
(22) Forster, M. O.; Schaeppi, J. H. J. Chem. Soc. 1912, 101, 382.
(23) Beringer, F. M.; Dehn, J. W.; Winicov, M. J. Am. Chem. Soc.
1960, 82, 2948.
(24) McRae, J. Ber. Dtsch. Chem. Ges. 1895, 28, 97.
(25) Willgerodt, C. J. Prakt. Chem. 1900, 61, 424.
(3) van der Puy, M. J. Fluorine Chem. 1982, 21, 385.
(4) Sandin, R. B. Chem. Rev. 1943, 32, 249; see p 266.
Synthesis 2008, No. 15, 2373–2380 © Thieme Stuttgart · New York