4-Methyl-N-(phenyl-λ³-iodaneylidene)benzenesulfonamide

• 1,2-Dihydronaphthalene [D0585]
• 4-Methyl-N-(phenyl-λ³-iodaneylidene)benzenesulfonamide (= PhINTs) [T3967]
• Bis(2,4-pentanedionato)copper(II) (= Cu(acac)₂) [C0384]
• Acetonitrile

1,2-Dihydronaphthalene (360 mg, 2.77 mmol) and bis(2,4-pentanedionato)copper(II) (60 mg, 0.233 mmol) were added sequentially to a solution of PhINTs (866 mg, 2.32 mmol) in acetonitrile (15 mL) and the mixture was stirred at room temperature. After stirring for 3 hours, the reaction mixture was filtered through, and the residue was washed with ethyl acetate (10 mL). The filtrate was concentrated under reduced pressure and the crude product was purified by silica gel column chromatography (hexane:ethyl acetate = 5:1) to afford N-tosyl-1,2,3,4-tetrahydronaphthalene-1,2-imine as a white solid (490 mg, 71% yield).

The reaction solution was monitored by TLC (hexane:ethyl acetate = 2:1, Rf= 0.40).
The residue obtained from the filtration was disposed as copper waste.

N-Tosyl-1,2,3,4-tetrahydronaphthalene-1,2-imine

¹H NMR (400 MHz, DMSO-d₆); δ 7.81 (d, J = 8.0 Hz, 2H), 7.30 (d, J = 8.2 Hz, 3H), 7.22-7.14 (m, 2H), 7.04 (d, J = 7.3 Hz, 1H), 3.81 (d, J = 7.0 Hz, 1H), 3.56-3.54 (m, 1H), 2.80-2.71 (m, 1H), 2.55-2.51 (m, 1H), 2.41 (s, 3H), 2.28-2.22 (m, 1H), 1.69-1.63 (m, 1H).

• Development of the Copper-Catalyzed Olefin Aziridination Reaction
  • D. A. Evans, M. T. Bilodeau, M. M. Faul, J. Am. Chem. Soc. 1994, 116, 2742.

• PhINTs [T3967]
• Methyl Phenyl Sulfoxide [M1148]
• Copper(II) Trifluoromethanesulfonate [T1292]
• Acetonitrile

To a solution of copper(II) trifluoromethanesulfonate (52 mg, 0.14 mmol) in acetonitrile (10 mL) was successively added methyl phenyl sulfoxide (0.20 g, 1.4 mmol) and PhINTs (0.59 g, 1.6 mmol) at room temperature under nitrogen atmosphere. The reaction mixture was stirred for 5 hours, then the solvent was removed under reduced pressure. The crude mixture was purified by column chromatography (ethyl acetate:hexane = 1:2 on silica gel), giving compound 1 as a white powder (0.31 g, 70% yield).

The reaction mixture was monitored by ¹H NMR (DMSO-d₆).
PhINTs must be kept cool and be avoided contact with some of organic solvents (ex. THF) due to its high reactivity.

¹H NMR (400 MHz, CDCl₃); δ 8.02 (d, 2H, J = 7.3 Hz), 7.86 (d, 2H, J = 8.2 Hz), 7.71 (t, 1H, J = 7.6 Hz), 7.61 (dd, 2H, J = 7.6, 8.2 Hz), 7.26 (d, 2H, J = 8.2 Hz), 3.43 (s, 3H), 2.40 (s, 3H).

¹³C NMR (101 MHz, CDCl₃); δ 143.0, 140.7, 138.4, 134.5, 129.9, 129.4, 127.6, 126.8, 46.8, 21.7.

• Catalytic Synthesis of Sulfoximines using Copper(II) Salts
• E. Lacôte, M. Amatore, L. Fensterbank, M. Malacria, Synlett 2002, 116.

• [N-(p-Toluenesulfonyl)imino]phenyliodinane
• D. A. Evans, D. A. Barnes, Encyclopedia of Reagents for Organic Synthesis 2001.