APPLICATION
TCI Practical Example: Diels-Alder Reaction Using the Benzyne Precursor
Used Chemicals
Phenyl[2-(trimethylsilyl)phenyl]iodonium Triflate [P1620]
Tetraphenylcyclopentadienone [T1062]
Tetrabutylammonium Fluoride (= TBAF) (ca. 1mol/L in Tetrahydrofuran) [T1338]
Dichloromethane
Procedure
To a solution of phenyl[2-(trimethylsilyl)phenyl]iodonium triflate (402 mg, 0.80 mmol) in CH2Cl2 (10 mL) was added tetraphenylcyclopentadienone (1.54 g , 4.0 mmol) under nitrogen and was cooled to 0 ˚C. TBAF (ca. 1mol/L solution in Tetrahydrofuran, 0.96 mL, 0.96 mmol) was added and the mixture was stirred at room temperature for 30 min. The reaction was quenched with water and extracted with CH2Cl2. The organic layer was dried over anhydrous sodium sulfate and filtered. The solvent was removed under reduced pressure and the crude was purified by column chromatography (ethyl acetate:hexane = 1:99 on silica gel) to give 1 as a white solid (296 mg, 86% yield).
Experimenter’s Comments
The reaction mixture was monitored by TLC (ethyl acetate: hexane = 1:99, Rf = 0.55).
This experiment was operated in a fume hood due to the generation of carbon monoxide.
Analytical Data
1,2,3,4-Tetraphenylnaphthalene (1)
1H NMR (270 MHz, CDCl3); δ 7.67-7.63 (m, 2H), 7.41-7.38 (m, 2H), 7.26-7.19 (m, 10H), 6.89-6.82 (m, 10H).
Lead Reference
A New and Efficient Hypervalent Iodine-Benzyne Precursor, (Phenyl)[o-(trimethylsilyl)phenyl]iodonium Triflate: Generation, Trapping Reaction, and Nature of Benzyne
T. Kitamura, M. Yamane, K. Inoue, Mi. Todaka, N. Fukatsu, Z. Meng, Y. Fujiwara, J. Am. Chem. Soc. 1999, 121, 11674.
Application
Useful Benzyne Precursors
PRECAUTIONARY STATEMENTS
P264 : Wash skin thoroughly after handling.
P280 : Wear protective gloves/ eye protection/ face protection.
P337 + P313 : If eye irritation persists: Get medical advice/ attention.
P305 + P351 + P338 : IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P302 + P352 : IF ON SKIN: Wash with plenty of soap and water.
P332 + P313 : If skin irritation occurs: Get medical advice/ attention.
P362 : Take off contaminated clothing and wash before reuse.
QUALITY CERTIFICATION / COMPLIANCE
Fukaya factory is certified for GMP, ISO14001:2004 (JQA-EM5386) and IQ Net (JP-JQA-EM5386).
![Phenyl[2-(trimethylsilyl)phenyl]iodonium Trifluoromethanesulfonate, CAS RN: 164594-13-2, Product Number: P1620](https://content.labscoop.com/products/0b59ce51-7f31-488c-b2db-687fc457cda9/KyTxwP1620.jpg)
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