Processos Químicos Orgânicos

Electronic Supplementary Information

Catalysis by Amberlite IR-120 resin: A rapid and green method for the synthesis of phenols from arylboronic acids under metal, ligand and base-free conditions

Naveen Mulakayala, ^[1]* Ismail, Kottur Mohan Kumar, Rajesh Kumar Rapolu, Bhaskar Kandagatla Pallavi Rao, Srinivas Oruganti , Manojit Pal ^[2]*

Cosmic Discoveries, Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad-500046, India.

General methods: Reactions were monitored by thin layer chromatography (TLC) on silica gel plates (60 F254), visualizing with ultraviolet light or iodine spray. 1H NMR spectra was determined in CDCl3 or DMSO-d6 solution by using 400 MHz spectrometer. Proton chemical shifts (δ) are relative to tetramethylsilane (TMS, δ = 0.00) as internal standard and expressed in ppm. Spin multiplicities are given as s (singlet), d (doublet), t (triplet) and m (multiplet) as well as b (broad). Coupling constants (J) are given in hertz. Infrared spectra were recorded on a FT- IR spectrometer. Melting points were determined using melting point apparatus and are uncorrected. MS spectra were obtained on a mass spectrometer

General procedure for the preparation of compound 3: A mixture of arylboronic acid (1.0 mmol), 30% H2O2 (2 mL) and Amberlite IR-120 resin (15 mg) was stirred at room temperature for the time indicated. After completion of the reaction (indicated by TLC) the solid was separated by filtration and the filtrate was washed with NaHCO3 (2 x 5 mL) and dried to give the desired product.

The recovered catalyst was washed with Acetone, dried and recycled for consecutive three times.

Phenol (2a)

[pic 1]

Colourless crystals; 1H NMR (400 MHz, CDCl3) δ ppm 7.25 (dd, J = 6.07, 2.34 Hz, 2H), 6.93 (t, J = 7.38 Hz, 1H), 6.83 (d, J = 7.71 Hz, 2H), 4.79 ( p, J = -1.#J Hz, 1H)

3-Chloro phenol (2b)

[pic 2]

Light Yellow liquid; 1H NMR (400 MHz, CDCl3) δ ppm 7.16 (t, J = 8.09 Hz, 1H), 6.95-6.89 (m, 1H), 6.86 (t, J = 2.10 Hz, 1H), 6.72 (dd, J = 8.17, 2.40 Hz, 1H), 5.08 (bs, 1H)

2-Fluoro phenol (2c)

[pic 3]

Colorless oil; 1H NMR (400 MHz, CDCl3) δ ppm 7.14-6.95 (m, 3H), 6.93-6.79 (m, 1H), 5.46-4.50 (m, 1H)

3-Fluoro phenol (2d)

[pic 4]

Colorless oil; 1H NMR (400 MHz, CDCl3) δ ppm 7.18 (dd, J = 14.92, 8.13 Hz, 1H), 6.69-6.54 (m, 3H), 5.52 (bs, 1H)

4-Fluorophenol (2e).

[pic 5]

white solid; 1H NMR (400 MHz, CDCl3) δ ppm 6.96-6.93( m, 2H) 6.84-6.69 (m, 2H), 5.02 (bs, 1H),

2-Iodophenol (2f).

[pic 6]

White solid; 1H NMR (400 MHz, CDCl3) δ ppm 7.66 (dd, J = 7.93, 1.39 Hz, 1H), 7.28-7.20 (m, 1H), 7.00 (dd, J = 8.12, 1.33 Hz, 1H), 6.73-6.63 (m, 1H), 5.28 (s, 1H)

4-Iodrophenol (2g).

[pic 7]

Colorless prisms; 1H NMR (400 MHz, CDCl3) δ ppm 7.51 (d, J = 8.69 Hz, 2H), 6.62 (d, J = 8.70 Hz, 2H), 5.05 (s, 1H)

3-Methoxyphenol (2h).

[pic 8]

Colorless oil; 1H NMR (400 MHz, CDCl3) δ ppm 7.14 (dd, J = 11.73, 4.72 Hz, 1H), 6.53-6.47 (m, 1H), 6.42 (dd, J = 8.26, 1.45 Hz, 2H), 4.81 (s, 1H), 3.78 (s, 3H)

4-Methoxy Phenol (2i).

[pic 9]

Colorless solid; 1H NMR (400 MHz, CDCl3) δ ppm 6.93-6.66 (m, 4H), 5.26-4.75 (m, 1H), 3.77 (s, 3H)

4-Hydroxybenzoic acid (2j):

[pic 10]

White solid; 1H NMR (400 MHz, CDCl3) δ ppm 9.61 (bs, 1H), 7.96-7.88 (m, 2H), 6.86 (dd, J = 8.72, 2.09 Hz, 2H)

4-Hydroxybenzaldehyde (2k).

[pic 11]

Yellowish solid; 1H NMR (400 MHz, CDCl3) δ ppm  9.85 (s, 1H), 7.83 (d, J = 8.56 Hz, 2H), 7.00 (d, J = 8.32 Hz, 2H), 6.90 ( bs, 1H)

2-Aminophenol (2l):

[pic 12]

Gray solid; 1H NMR (400 MHz, CDCl3) δ ppm 6.76 (m, 4H), 5.06 (bs, 1H), 3.82 (bs, 2H)