[Bis(trifluoroacetoxy)iodo]benzene

Used Chemicals

• [Bis(trifluoroacetoxy)iodo]benzene (= PIFA) [B1175]
• 2-(4-Chlorophenyl)-1,3-dithiane [C3649]
• Acetonitrile

Procedure

PIFA (745 mg, 1.72 mmol, 2.0 eq.) was added to a solution of 2-(4-chlorophenyl)-1,3-dithiane (200 mg, 0.87 mmol) in acetonitrile/H₂O (4:1, 8.7 mL) at 0 °C. The reaction mixture was stirred for 2.5 h. sat. NaHCO₃ aq. (10 mL) was added and extracted with dichloromethane (3 x 10 mL). The organic layer was washed with brine, dried over sodium sulfate and filtered. The solvent was removed under reduced pressure and the residue was purified by column chromatography (ethyl acetate:hexane = 5:95 – 15:85 on silica gel), giving p-chlorobenzaldehyde (ca. 93.7 mg, 76% yield) as a pale yellow solid.

Experimenter’s Comments

The reaction mixture was monitored by TLC (ethyl acetate:hexane = 5:1, Rf = 0.5).
p-Chlorobenzaldehyde was obtained as a mixture of iodobenzene (p-chlorobenzaldehyde:iodobenzene = 1.0:0.08 on NMR), so that the yield was calculated taking it into consideration.

Analytical Data

p-chlorobenzaldehyde

¹H NMR (270 MHz, CDCl₃); δ 9.99 (s, 1H), 7.84 (td, J = 1.9, 8.6 Hz, 2H), 7.53 (td, J = 1.9, 8.6 Hz, 2H).

Other Reference

• Preparation of Unsymmetrical Ketones from Tosylhydrazones and Aromatic Aldehydes via Formyl C-H Bond Insertion
• D. M. Allwood, D. C. Blakemore, S. V. Ley, Org. Lett. 2014, 16, 3064.

References

• Protection for the Hydroxyl Group, Including 1,2- and 1,3-Diols
  • P. G. M. Wuts, in Greene’s Protective Groups in Organic Synthesis, 5th ed., ed. by P. G. M. Wuts, John Wiley & Sons, Inc., Hoboken, New Jersey, 2014, Chap. 2, 17.

References

• S. Yoshino, K. Hayakawa, K. Kanematsu, J. Org. Chem. 1981, 46, 3841.
• K. Hayakawa, M. Aso, K. Kanematsu, J. Org. Chem. 1985, 50, 2036.
• Y. Okamoto, K. Senokuchi, K. Kanematsu, Chem. Pharm. Bull. 1984, 32, 4593.
• K. Kanematsu, S. Morita, S. Fukushima, E. Osawa, J. Am. Chem. Soc. 1981, 103, 5211.