Table of Contents - Royal Society of Chemistry · standard;1H NMR at δ 7.26 ppm and 13C NMR at δ...

Supporting Information

SI-1

Table of Contents General considerations ............................................................................................................................ 3 Representative general procedure for the oxidative esterification of aldehydes ..................................... 3 Procedure for the large-scale oxidative esterification ............................................................................. 3 Procedure for the kinetic study ................................................................................................................ 4 Representative procedure for the sequential addition.............................................................................. 4 Representative general procedure for the NHC-catalyzed oxidative Michael addition .......................... 5 NMR spectra of compounds .................................................................................................................... 9

1H NMR of methyl cinnamate............................................................................................................. 9 13C NMR of methyl cinnamate ........................................................................................................... 9 1H NMR of methyl 4-chlorocinnamate ............................................................................................. 10 13C NMR of methyl 4-chlorocinnamate ............................................................................................ 10 1H NMR of methyl 4-fluorocinnamate ............................................................................................. 11 13C NMR of methyl 4-fluorocinnamate ............................................................................................ 11 19F NMR of methyl 4-fluorocinnamate ............................................................................................. 12 1H NMR of methyl 4-methylcinnamate ............................................................................................ 13 13C NMR of methyl 4-methylcinnamate ........................................................................................... 13 1H NMR of methyl 4-methoxycinnamate ......................................................................................... 14 13C NMR of methyl 4-methoxycinnamate ........................................................................................ 14 1H NMR of methyl 4-nitrocinnamate ................................................................................................ 15 13C NMR of methyl 4-nitrocinnamate ............................................................................................... 15 1H NMR of methyl 2-nitrocinnamate ................................................................................................ 16 13C NMR of methyl 2-nitrocinnamate ............................................................................................... 16 1H NMR of isopropyl cinnamate ....................................................................................................... 17 13C NMR of isopropyl cinnamate ..................................................................................................... 17 1H NMR of benzyl 4-methoxycinnamate .......................................................................................... 18 13C NMR of benzyl 4-methoxycinnamate ......................................................................................... 18 1H NMR of phenethyl 4-methoxycinnamate ..................................................................................... 19 13C NMR of phenethyl 4-methoxycinnamate .................................................................................... 19 1H NMR of ethyl 4-methoxycinnamate ............................................................................................ 20 13C NMR of ethyl 4-methoxycinnamate ........................................................................................... 20 1H NMR of allyl 4-methoxycinnamate ............................................................................................. 21 13C NMR of allyl 4-methoxycinnamate ............................................................................................ 21 1H NMR of isoamyl 4-methoxycinnamate ........................................................................................ 22 13C NMR of isoamyl 4-methoxycinnamate ....................................................................................... 22 1H NMR of triethylene glycol monomethyl 4-methoxycinnamate ................................................... 23 13C NMR of triethylene glycol monomethyl 4-methoxycinnamate .................................................. 23 1H NMR of 2’-ethyl-hexyl 4-methoxycinnamate.............................................................................. 24

Electronic Supplementary Material (ESI) for Green Chemistry.This journal is © The Royal Society of Chemistry 2015


SI-2

13C NMR of 2’-ethyl-hexyl 4-methoxycinnamate ............................................................................ 24 1H NMR of 4-hydroxybutyl cinnamate ............................................................................................. 25 13C NMR of 4-hydroxybutyl cinnamate ............................................................................................ 25 1H NMR of methyl benzoate ............................................................................................................. 26 13C NMR of methyl benzoate ............................................................................................................ 26 1H NMR of sorbic acid 2-phenylethylester ....................................................................................... 27 13C NMR of sorbic acid 2-phenylethylester ...................................................................................... 27 1H NMR of ethyl 6-methyl-2-oxo-4-phenyl-3,4-dihydro-2H-pyran-5-carboxylate .......................... 28 13C NMR of ethyl 6-methyl-2-oxo-4-phenyl-3,4-dihydro-2H-pyran-5-carboxylate ......................... 28 1H NMR of 5-Acetyl-4-(4-methoxyphenyl)-6-methyl-3,4-dihydro-2H-pyran-2-one ....................... 29 13C NMR of 5-Acetyl-4-(4-methoxyphenyl)-6-methyl-3,4-dihydro-2H-pyran-2-one ...................... 29 1H NMR of 5-Acetyl-6-methyl-4-phenyl-3,4-dihydro-2H-pyran-2-one ........................................... 30 13C NMR of 5-Acetyl-6-methyl-4-phenyl-3,4-dihydro-2H-pyran-2-one .......................................... 30


SI-3

General considerations 1,4-dimethyl-4H-1,2,4-trizole iodide was synthesized according to literature procedure.1, 2 Cinnamaldehyde was stored under an atmosphere of nitrogen. All other solvents and reagents were purchased from commercial sources and used without modifications. Synthesis of catalyst 3-benzyl-4,5-dimethylthiazol-3-ium chloride was performed according to literature procedure.3 3,3’,5,5’-tetra-tert-butyldiphenoquinone was synthesized according to literature procedure.4 1H NMR (400 MHz), 13C NMR (101 MHz) and 19F NMR (376 MHz) spectra were acquired on Varian 400. The chemical shifts for 1H and 13C NMR spectra are reported in parts per million (ppm) relative to the residual peak from solvent CDCl3 as the internal standard; 1H NMR at δ 7.26 ppm and 13C NMR at δ 77.16 ppm. All coupling constants (J) are reported in Hertz (Hz) and multiplicities are indicated by s (singlet), d (doublet), t (triplet), q (quartet), hept (heptet) and m (multiplet). GC-FID was performed on a GC Varian 3900 with an autosampler equipped with an EQUITYTM-5 column (30 m × 0.25 mm × 0.25 µm) and hydrogen as carrier gas. GC-FID method used: 80 °C, 2 min; 20 °C/min to 300 °C, 2 min; injector temperature 300 °C. The yield of the kinetic studies were measured with GC-FID using chloro-benzene as internal standard, standardized by calibration against authentic samples of pure starting material. Rt (chloro-benzene) = 2.1 min. Purification was performed by an automated column chromatography Biotage Isolera™ Spektra One with Biotage SNAP®-10 g KP-sil columns. Flash chromatography was performed with silica gel for chromatography (35–70 micron) in the solvent reported. Thin layer chromatography (TLC) was performed on Merck TLC plates precoated with silica gel 60 F254 (Art 5715, 0.25 mm) and was visualized with UV-light (254 nm). All isolated products are in accordance with the reported values in the literature.

Representative general procedure for the oxidative esterification of aldehydes To a vial equipped with a magnetic stir bar were added iron(II)phthalocyanine (1.5 mg, 0.003 mmol), 1,4-dimethyl-4H-1,2,4-trizole iodide (2.2 mg, 0.01 mmol), 2,6-di-tert-butylphenol (2.1 mg, 0.01 mmol), 1,5,7-triazole[4.4.0]dec-5-ene (34.8 mg, 0.25 mmol), acetonitrile (1 mL) and methanol (63.9 mg, 82 μL, 2 mmol). The mixture was stirred for 3 minutes at ambient temperature in air; thereafter cinnamaldehyde (66.1 mg, 0.5 mmol) was added. The mixture was stirred at ambient temperature and in contact with air. Completion of the reaction was monitored via TLC. After 3 h the reaction mixture was purified with the biotage using petroleum ether (40–60 °C)/ethyl acetate solvent mixture (25 ml/min, 100% petroleum ether→1%→2%→5%→15% ethyl acetate in petroleum ether). The product was obtained as a yellow solid (70.6 mg, 0.44 mmol, 87% yield).

Procedure for the large-scale oxidative esterification To a 100 ml round bottom flask equipped with a magnetic stir bar were added iron(II)phthalocyanine (18.9 mg, 0.03 mmol), 1,4-dimethyl-4H-1,2,4-trizole iodide (29.1 mg, 0.13 mmol), 2,6-di-tert-butylphenol (26.7 mg, 0.12 mmol), 1,5,7-triazole[4.4.0]dec-5-ene (435.2 mg, 3.13 mmol), acetonitrile (12 mL) and benzyl alcohol (2.594 g, 24.2 mmol). The mixture was stirred for 5 minutes at ambient temperature in air; thereafter 4-methoxycinnamaldehyde (983.1 mg, 6.06 mmol) was added. The mixture was stirred at ambient temperature and in contact with air. Completion of the reaction was monitored via 1H NMR. After 7 h the reaction mixture was purified via flash chromatography (petroleum ether/ethyl acetate 95:5). The product was obtained as a pale yellow solid (1543.9 mg, 5.75 mmol, 95% yield).


SI-4

Procedure for the kinetic study The kinetic studies was performed following the procedure for the representative general procedure. Chloro-benzene (50.9 µL, 0.5 mmol) was added as an internal standard. Aliquots (10 µL) were collected by syringe, filtered through a short plug of silica and eluated with DCM (2 mL) before analysis by GC-FID.

Representative procedure for the sequential addition To a 10 ml round bottom flask equipped with a magnetic stir bar were added iron(II)phthalocyanine (1.5 mg, 0.003 mmol), 1,4-dimethyl-4H-1,2,4-trizole iodide (2.2 mg, 0.01 mmol), 2,6-di-tert-butylphenol (2.1 mg, 0.01 mmol), 1,5,7-triazole[4.4.0]dec-5-ene (34.8 mg, 0.25 mmol), acetonitrile (1 mL) and methanol (63.9 mg, 2 mmol). The mixture was stirred for 3 minutes at ambient temperature in air; thereafter cinnamaldehyde (68.9 mg, 0.52 mmol) was added. The mixture was stirred at ambient temperature and in contact with air. After 30 minutes additional cinnamaldehyde (69.2 mg, 0.52 mmol) and methanol (32.4 mg, 0.99 mmol) were added. After additionally 30 minutes cinnamaldehyde (67.0 mg, 0.51 mmol) was added. The reaction mixture was stirred over night and was purified via flash chromatography (100% heptane followed by 15% EtOAc in heptane). The sequential procedure was performed using two and three additions, for each addition one extra equivalent of cinnamaldehyde and methanol were used, added with 30 minutes intervals. The result from adding all of the starting materials (cinnamaldehyde and methanol) in the first addition was used as a reference point. The results of the different sequential additions are summarized in table S1. In entry 1 and 3, cinnamaldehyde was still present when the reaction was stopped.

Table S1. The results of the sequential addition experiments.

Entry Number of additions Average yield 1a. 2 43%b 2. 2 86% c 3. 3 71% c a All of the starting material added in the first addition.

b Yield determined by 1H NMR using 1,2,4,5-tetramethylbenzene as internal standard. c Isolated yield, following the representative procedure.


SI-5

Representative general procedure for the NHC-catalyzed oxidative Michael addition To a round bottom flask (10 mL) equipped with a magnetic stirrer were added 1,4-dimethyl-4H-1,2,4-trizole iodide (6.0 mg, 0.027 mmol), 3,3',5,5'-tetra-tert-butyldiphenoquinone (10.6 mg, 0.026 mmol), tetrahydrofuran (5 ml) and 1,8-diazabicyclo[5.4.0]undec-7-ene (9.1 mg, 0.06 mmol). The mixture was stirred for 5 minutes at ambient temperature and in contact with air. Ethyl acetoacetate (97.6 mg, 0.75 mmol) was added to the mixture and the mixture was stirred for additional 5 minutes. Iron(II)phthalocyanine (14.2 mg, 0.05 mmol) and cinnamaldehyde (70.1 mg, 0.53 mmol) were added and the mixture was stirred at ambient temperature in contact with air. Completion of the reaction was monitored via 1H NMR. After 4 h the reaction mixture was purified with the biotage using ethyl acetate/heptane solvent mixture (25 ml/min, 100% heptane→2%→5%→10%→15%→20%→50 ethyl acetate in heptane). The product was obtained as a white solid (127.6 mg, 0.49 mmol, 92% yield).

Methyl cinnamate5: Synthesized from cinnamaldehyde and methanol according to the representative procedure. Obtained as a yellow solid (70.6 mg, 0.44 mmol, 87% yield). 1H NMR (400 MHz, CDCl3) δ 7.70 (1 H d, J = 16.0 Hz), 7.54–7.49 (2 H, m), 7.41–7.35 (3 H, m), 6.44 (1 H, d, J = 16.0

Hz), 3.80 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.5, 144.9, 134.5, 130.4, 129.0, 128.1, 117.9, 51.8.

Methyl 4-chlorocinnamate5: Synthesized from 4-chlorocinnamaldehyde and methanol according to the representative procedure. Obtained as a white solid (85.4 mg, 0.43 mmol, 87% yield). 1H NMR (400 MHz, CDCl3) δ 7.61 (1 H, d, J = 16.0 Hz), 7.45–7.38 (2

H, m), 7.37–7.29 (2 H, m), 6.38 (1 H, d, J = 16.0 Hz), 3.78 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.2, 143.4, 136.2, 132.9, 129.3, 129.2, 118.4, 51.8.

Methyl 4-fluorocinnamate6: Synthesized from methanol and 4-fluorocinnamaldehyde according to the representative procedure. Obtained as a yellow solid (65.2 mg, 0.36 mmol, 73%). 1H NMR (400 MHz, CDCl3) δ 7.66 (1 H, d, J = 16.0 Hz), 7.55–7.46 (2 H, m), 7.13–7.01

(2 H, m), 6.36 (1 H, d, J = 16.0 Hz), 3.81 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.4, 164.1 (d, 1JC-F = 251 Hz), 143.7, 130.8, 130.1 (d, 3JC-F = 8.4 Hz), 117.7, 116.2 (d, 2JC-F = 22.1 Hz), 51.9. 19F NMR (376 MHz, CDCl3) δ – 109.6.

Methyl 4-methylcinnamate7: Synthesized from methanol and 4-methyl cinnamate according to the representative procedure. Obtained as a yellow solid (65.1 mg, 0.37 mmol), 72%). 1H NMR (400 MHz, CDCl3) δ 7.67 (1 H, d, J = 16.0 Hz), 7.42 (2 H, d, J = 8.1 Hz), 7.19 (2 H, d, J = 7.9

Hz), 6.40 (1 H, d, J = 16.0 Hz), 3.80 (3 H, s), 2.37 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.7, 145.1, 144.8, 140.8, 131.8, 130.0, 129.5, 128.4, 127.9, 117.0, 117.0, 116.7, 51.8, 21.8.


SI-6

Methyl 4-methoxycinnamate5: Synthesized from 4-methoxycinnamaldehyde and methanol according to the representative procedure. Obtained as a white solid (87.9 mg, 0.46 mmol, 88% yield). 1H NMR (400 MHz, CDCl3) δ 7.63 (1 H, d, J = 16.0 Hz), 7.48–7.40 (2

H, m), 6.91–6.83 (2 H, m), 6.28 (1 H, d, J = 16 Hz), 3.79 (3 H, s), 3.76 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.7, 161.4, 144.5, 129.7, 127.1, 115.3, 114.3, 55.3, 51.6.

Methyl 4-nitrocinnamate8: Synthesized from 4-nitrocinnamaldehyde (predominantly trans) and methanol according to the representative procedure. Obtained as a white solid (79.5 mg, 0.38 mmol, 79% yield, predominantly trans-isomer). 1H NMR (400 MHz, CDCl3) δ 8.24 (2 H,

d, J = 8.6 Hz), 7.72 (1 H, d, J = 16.1 Hz), 7.69–7.65 (2 H, m), 6.56 (1 H, d, J = 16.0 Hz), 3.84 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 166.6, 148.6, 142.0, 140.4, 128.8, 124.3, 122.2, 52.2.

Methyl 2-nitrocinnamate9: Synthesized from 2-nitrocinnamaldehyde and methanol according to the representative procedure. Obtained as a yellow solid (66.8 mg, 0.32 mmol, 64% yield). 1H NMR (400 MHz, CDCl3) δ 8.12 (1 H, d, J = 16.6 Hz), 8.07–8.02 (1 H, m), 7.68–7.60 (2 H, m), 7.57–7.51 (1

H, m), 6.37 (1 H, d, J = 16.4 Hz), 3.83 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 166.3, 140.3, 133.7, 130.5, 129.3, 125.1, 123.1, 52.2.

Isopropyl cinnamate10: Synthesized from cinnamaldehyde and isopropanol according to the representative procedure. Obtained as yellow oil (84.6 mg, 0.44 mmol, 89% yield). 1H NMR (400 MHz, CDCl3) δ 7.67 (1 H, d, J = 16.0 Hz), 7.55–7.49 (2 H, m), 7.42–7.33 (2 H,

m), 6.42 (1 H, d, J = 16.0 Hz), 5.14 (1 H, hep, J = 6.3 Hz) 1.32 (6 H, d, J = 6.3 Hz). 13C NMR (101 MHz, CDCl3) δ 166.7, 144.4, 134.7, 130.3, 129.0, 128.1, 119.0, 67.9, 22.1.

Benzyl 4-methoxycinnamate11: Synthesized from 4-methoxycinnamaldehyde and benzyl alcohol according to the representative procedure and the procedure for the large-scale oxidative esterification. Obtained as a pale yellow solid (84.6

mg, 0.44 mmol, 98% yield) and (1543.9 mg, 5.75 mmol, 95% yield) respectively. 1H NMR (400 MHz, CDCl3) δ 7.71 (1 H, d, J = 16.0 Hz), 7.52–7.30 (7H, m), 6.93–6.88 (2 H, m), 6.36 (1 H, d, J = 16.0 Hz), 5.25 (2 H, s), 3.84 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.3, 161.6 145.0, 136.4, 129.9, 128.7, 128.4, 128.3, 127.2, 115.5, 114.5, 66.3, 55.5.

Phenethyl 4-methoxycinnamate12: Synthesized from 4-methoxycinnamaldehyde and 2-phenylethanol according to the representative procedure. Obtained as a white solid (136.2 mg, 0.48 mmol, 96% yield). 1H NMR (400 MHz, CDCl3) δ 7.66 (1

H, d, J = 16.0 Hz), 7.52–7.47 (2 H, m), 7.38–7.27 (5 H, m), 6.95–6.87 (2 H, m), 6.32 (1 H, d, J = 16.0 Hz), 4.44 (2 H, t, J = 7.1 Hz), 3.86 (3 H, s), 3.04 (2 H, t, J = 7.1 Hz). 13C NMR (101 MHz, CDCl3) δ 167.4, 161.5, 144.6, 138.1, 129.9, 129.1, 128.6, 127.3, 126.7, 115.7 114.5, 65.0, 55.5, 35.4.


SI-7

Ethyl 4-methoxycinnamate13: Synthesized from 4-methoxycinnamaldehyde and ethanol according to the representative procedure. Obtained as a clear oil (95.8 mg, 0.46 mmol, 93% yield). 1H NMR (400 MHz, CDCl3) δ 7.64 (1 H, d, J = 16.0 Hz), 7.51–7.43

(2 H, m), 6.94–6.86 (2 H, m), 6.31 (1 H, d, J = 16.0 Hz), 4.25 (2 H, q, J = 7.1 Hz), 3.84 (3 H, s), 1.33 (3 H, t, J = 7.1 Hz). 13C NMR (101 MHz, CDCl3) δ 167.4, 161.4, 144.3, 129.7, 127.3, 115.8, 114.4, 60.4, 55.4, 14.4.

Allyl 4-methoxycinnamate14: Synthesized from 4-methoxycinnamaldehyde and allyl alcohol according to the representative procedure. Obtained as colorless oil. (86.3 mg, 0.39 mmol, 78% yield). 1H NMR (400 MHz, CDCl3) δ 7.67 (1 H, d, J =

16.0 Hz), 7.51–7.45 (2 H, m), 6.94–6.87 (2 H, m), 6.34 (1 H, d, J = 16.0 Hz), 6.05–5.93 (1 H, m), 5.41–5.33 (1 H, m), 5.29–5.23 (1 H, m), 4.73–4.67 (2 H, m), 3.84 (3H, s). 13C NMR (101 MHz, CDCl3) δ 167.1, 161.6, 144.9, 132.6, 129.9, 127.3, 118.3, 115.5, 114.5, 65.2, 55.5

Isoamyl 4-methoxycinnamate15: Synthesized from isoamyl alcohol and 4-methoxycinnamaldehyde according to the representative procedure, however, using only isoamyl alcohol as solvent. Obtained as a yellow oil (90.6 mg, 0.36 mmol, 72%). 1H

NMR (400 MHz, CDCl3) δ 7.63 (1 H, d, J = 16.0 Hz), 7.51–7.44 (2 H, m), 6.94–6.87 (2 H, m), 6.31 (1 H, d, J = 16.0 Hz), 4.23 (2 H, t, J = 6.9 Hz), 3.84 (3 H, s), 1.80–1.69 (1 H, m), 1.60 (2 H, q, J = 6.9 Hz), 0.96 (3 H, s), 0.95 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.6, 161.5, 144.3, 129.8, 127.4, 115.9, 114.5, 63.2, 55.5, 37.6, 25.3, 22.7.

Triethylene glycol monomethyl 4-methoxycinnamate16: Synthesized from triethylene glycol monomethyl ether and 4-methoxycinnamaldehyde. Obtained as a yellow oil

(124.3 mg, 0.38 mmol. 76%). 1H NMR (400 MHz, CDCl3) δ 7.66 (1 H, d, J = 15.9 Hz), 7.53–7.43 (2H, m), 6.95–6.85 (2 H, m), 6.34 (1 H, d, J = 16.0 Hz), 4.41–4.31 (2 H, m), 3.84 (3 H, s), 3.81–3.74 (2 H, m), 3.74–3.63 (6 H, m), 3.59–3.51 (2 H, m), 3.37 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 167.4, 161.6, 144.9, 129.9, 127.3, 115.5, 114.5, 72.1, 70.8, 69.5, 63.7, 59.2, 55.5.

2’-ethylhexyl 4-methoxycinnamate15: Synthesized from 2-ethylhexan-1-ol and 4-methoxycinnamaldehyde. Obtained as a yellow oil (104.0 mg, 0.36 mmol, 72%). 1H NMR (400 MHz, CDCl3) δ 7.63 (1 H, d, J = 16.1 Hz), 7.48 (2 H, d, J =

8.7 Hz), 6.90 (2 H, d, J = 8.6 Hz), 6.32 (1 H, d, J = 16.0 Hz), 4.15–4.07 (2 H, m), 3.84 (3 H, s), 1.45–1.27 (9 H, m), 0.95–0.88 (6 H, m). 13C NMR (101 MHz, CDCl3) δ 116.7, 161.4, 144.3, 129.9, 127.4, 114.4, 66.9, 55.5, 39.0, 30.6, 29.1, 24.0, 23.1, 14.2 11.1.


SI-8

4-hydroxybutyl cinnamate17: Synthesized from 1,4-butanediol and cinnamaldehyde according to general procedure, however, using more acetonitrile (4 mL) for a more dilute reaction mixture. Obtained as a colorless oil (80.4 mg, 0.37 mmol, 74% yield). 1H

NMR (400 MHz, CDCl3) δ 7.69 (1 H, d, J = 16.0 Hz), 7.57–7.49 (2 H, m), 7.43–7.36 (3 H, m), 6.44 (1 H, d, J = 16.0 Hz), 4.26 (2 H, t, J = 6.5 Hz), 3.72 (2 H, t, J = 6.4 Hz), 1.86–1.77 (2 H, m), 1.74–1.65 (2 H, m). 13C NMR (101 MHz, CDCl3) δ 167.2, 144.9, 134.5, 130.4, 129.0, 129.0, 128.2, 118.2, 77.2, 64.5, 62.6, 29.3, 25.4.

Methyl benzoate: Synthesized from methanol and benzaldehyde according to general procedure. Obtained as a yellow oil (101.8 mg, 0.75 mmol, 75% yield). 1H NMR (400 MHz, CDCl3) δ 8.06-8.03 (2 H, m), 7.58–7.53 (1 H, m), 7.46–7.41 (2 H, m), 3.92 (3 H, s) 13C NMR (101 MHz, CDCl3) δ 167.3, 133.0, 130.3,

129.7, 128.5, 52.2. Sorbic acid 2-phenylethylester18: Synthesized from 2-phenylethanol and sorbic aldehyde (mixture of stereoisomers, predominantly 2E,4E) according to general procedure. Obtained as

a yellow oil (predominantly 2E,4E, 74.6 mg, 0.34 mmol, 69% yield). 1H NMR (400 MHz, CDCl3) δ 7.32–7.27 (2 H, m), 7.25–7.19 (4 H, m), 6.19–6.08 (2 H, m), 5.75 (1 H, d, J = 15.4 Hz), 4.34 (2 H, t, J = 7.1 Hz), 2.96 (2 H, t, J = 7.1 Hz), 1.84 (3 H, d, J = 5.9 Hz) 13C NMR (101 MHz, CDCl3) δ 167.3, 145.3, 139.6, 138.1, 129.9, 129.1, 128.6, 126.6, 119.0, 64.9, 35.4, 18.8.

Ethyl 6-methyl-2-oxo-4-phenyl-3,4-dihydro-2H-pyran-5-carboxylate19: Synthesized in accordance to the representative procedure from cinnamaldehyde and ethyl acetoacetate. Obtained as a white solid (127.6 mg, 0.49 mmol, 92% yield). 1H NMR (400 MHz, CDCl3) δ 7.32–7.27 (2 H, m), 7.26–7.20 (1 H, m), 7.17–7.11 (2 H, m), 4.29–4.23 (1 H, m), 4.13 (2 H, q, J = 7.1 Hz), 2.94 (1 H, dd, J = 15.9 Hz, 7.8 Hz), 2.82 (1 H, dd, J = 15.9 Hz, 2.4

Hz), 2.47 (3 H, d, J = 1.0 Hz), 1.18 (3 H, t, J = 7.5 Hz). 13C NMR (101 MHz, CDCl3) δ 166.2, 166.0, 161.4, 140.8, 129.1, 127.6, 126.7, 110.1, 61.0, 38.0, 36.5, 19.0, 14.2.

5-Acetyl-4-(4-methoxyphenyl)-6-methyl-3,4-dihydro-2H-pyran-2-one19: Synthesized in accordance to the representative procedure from 4-methoxycinnamaldehyde and acetylacetone. Obtained as a light yellow solid (118.9 mg, 0.46 mmol, 82% yield). 1H NMR (400 MHz, CDCl3) δ 7.09–7.01 (2 H, m), 6.90–6.81 (2 H, m), 4.12–4.06 (1 H, m), 3.76 (3 H, s),

2.92 (1 H, dd, J = 15.6 Hz, 7.2 Hz), 2.79 (1 H, dd, J = 15.6 Hz, 2.7 Hz), 2.40 (3 H, d, J = 1.0 Hz), 2.10 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 198.1, 165.9, 160.1, 159.3, 131.6, 127.9, 117.6, 114.9, 55.3, 38.2, 37.5, 29.8, 19.1.

5-Acetyl-6-methyl-4-phenyl-3,4-dihydro-2H-pyran-2-one19: Synthesized in accordance to the representative procedure from cinnamaldehyde and acetylacetone. Obtained as a white solid (118.0 mg, 0.41 mmol, 80% yield). 1H NMR (400 MHz, CDCl3) δ 7.32–7.28 (2 H, m), 7.27–7.23 (1 H, m), 7.15–7.10 (2 H, m), 4.16–4.10 (1 H, m), 2.94 (1 H, dd, J = 15.6 Hz, 7.2 Hz), 2.80 (1

H, dd, J = 15.7 Hz, 2.7 Hz) 2.40 (3 H, d, J = 0.9 Hz), 2.10 (3 H, s). 13C NMR (101 MHz, CDCl3) δ 197.9, 165.6, 160.2, 139.7, 129.3, 127.8, 126.6, 117.3, 38.9, 37.2, 29.7, 19.0.


SI-9

NMR spectra of compounds 1H NMR of methyl cinnamate (CDCl3)

13C NMR of methyl cinnamate (CDCl3)


SI-10

1H NMR of methyl 4-chlorocinnamate (CDCl3)

13C NMR of methyl 4-chlorocinnamate (CDCl3)


SI-11

1H NMR of methyl 4-fluorocinnamate (CDCl3)

13C NMR of methyl 4-fluorocinnamate (CDCl3)


SI-12

19F NMR of methyl 4-fluorocinnamate (CDCl3)


SI-13

1H NMR of methyl 4-methylcinnamate (CDCl3)

13C NMR of methyl 4-methylcinnamate (CDCl3)


SI-14

1H NMR of methyl 4-methoxycinnamate (CDCl3)

13C NMR of methyl 4-methoxycinnamate (CDCl3)


SI-15

1H NMR of methyl 4-nitrocinnamate (CDCl3)

13C NMR of methyl 4-nitrocinnamate (CDCl3)


SI-16

1H NMR of methyl 2-nitrocinnamate (CDCl3)

13C NMR of methyl 2-nitrocinnamate (CDCl3)


SI-17

1H NMR of isopropyl cinnamate (CDCl3)

13C NMR of isopropyl cinnamate (CDCl3)


SI-18

1H NMR of benzyl 4-methoxycinnamate (CDCl3)

13C NMR of benzyl 4-methoxycinnamate (CDCl3)


SI-19

1H NMR of phenethyl 4-methoxycinnamate (CDCl3)

13C NMR of phenethyl 4-methoxycinnamate (CDCl3)


SI-20

1H NMR of ethyl 4-methoxycinnamate (CDCl3)

13C NMR of ethyl 4-methoxycinnamate (CDCl3)


SI-21

1H NMR of allyl 4-methoxycinnamate (CDCl3)

13C NMR of allyl 4-methoxycinnamate (CDCl3)


SI-22

1H NMR of isoamyl 4-methoxycinnamate (CDCl3)

13C NMR of isoamyl 4-methoxycinnamate (CDCl3)


SI-23

1H NMR of triethylene glycol monomethyl 4-methoxycinnamate (CDCl3)

13C NMR of triethylene glycol monomethyl 4-methoxycinnamate (CDCl3)


SI-24

1H NMR of 2’-ethyl-hexyl 4-methoxycinnamate (CDCl3)

13C NMR of 2’-ethyl-hexyl 4-methoxycinnamate (CDCl3)


SI-25

1H NMR of 4-hydroxybutyl cinnamate (CDCl3)

13C NMR of 4-hydroxybutyl cinnamate (CDCl3)


SI-26

1H NMR of methyl benzoate (CDCl3)

13C NMR of methyl benzoate (CDCl3)


SI-27

1H NMR of sorbic acid 2-phenylethylester (CDCl3)

13C NMR of sorbic acid 2-phenylethylester (CDCl3)


SI-28

1H NMR of ethyl 6-methyl-2-oxo-4-phenyl-3,4-dihydro-2H-pyran-5-carboxylate (CDCl3)

13C NMR of ethyl 6-methyl-2-oxo-4-phenyl-3,4-dihydro-2H-pyran-5-carboxylate (CDCl3)


SI-29

1H NMR of 5-Acetyl-4-(4-methoxyphenyl)-6-methyl-3,4-dihydro-2H-pyran-2-one (CDCl3)

13C NMR of 5-Acetyl-4-(4-methoxyphenyl)-6-methyl-3,4-dihydro-2H-pyran-2-one (CDCl3)


SI-30

1H NMR of 5-Acetyl-6-methyl-4-phenyl-3,4-dihydro-2H-pyran-2-one (CDCl3)

13C NMR of 5-Acetyl-6-methyl-4-phenyl-3,4-dihydro-2H-pyran-2-one (CDCl3)


SI-31

1. J. L. Belletire, R. A. Bills and S. A. Shackelford, Synth. Communications, 2008, 38, 738-745.

2. S. Guo and H. V. Huynh, Organometallics, 2012, 31, 4565-4573. 3. K. Y.-K. Chow and J. W. Bode, J. Am. Chem. Soc., 2004, 126, 8126-8127. 4. A. Krasovskiy, A. Tishkov, V. del Amo, H. Mayr and P. Knochel, Angew. Chem. In.

Ed., 2006, 45, 5010-5014. 5. J. Ruan, X. Li, O. Saidi and J. Xiao, J. Am. Chem. Soc., 2008, 130, 2424-2425. 6. H. G. Lee, P. J. Milner and S. L. Buchwald, Org. Lett., 2013, 15, 5602-5605. 7. Z. He, S. Kirchberg, R. Fröhlich and A. Studer, Angew. Chem. Int. Ed., 2012, 51,

3699-3702. 8. C. J. O'Brien, J. L. Tellez, Z. S. Nixon, L. J. Kang, A. L. Carter, S. R. Kunkel, K. C.

Przeworski and G. A. Chass, Angew. Chem. Int. Ed., 2009, 48, 6836-6839. 9. J. Dambacher, W. Zhao, A. El-Batta, R. Anness, C. Jiang and M. Bergdahl,

Tetrahedron Lett., 2005, 46, 4473-4477. 10. P. Mathur, R. K. Joshi, B. Jha, A. K. Singh and S. M. Mobin, J. Organomet. Chem.,

2010, 695, 2687-2694. 11. A. El-Batta, C. Jiang, W. Zhao, R. Anness, A. L. Cooksy and M. Bergdahl, J. Org.

Chem., 2007, 72, 5244-5259. 12. H. Shi, D. Xie, R. Yang and Y. Cheng, J. Agr. Food Chem., 2014, 62, 5046-5053. 13. S. Mun, J.-E. Lee and J. Yun, Org. Lett., 2006, 8, 4887-4889. 14. S. H. Barley, A. Gilbert and G. R. Mitchell, Makromolekul. Chem., 1991, 192, 2801-

2810. 15. B. List, A. Doehring, M. T. Hechavarria Fonseca, A. Job and R. Rios Torres,

Tetrahedron, 2006, 62, 476-482. 16. C. Nourary, A. Castellan and R. S. Davidson, J. Photoch. Photobio. A., 1994, 84, 317-

326. 17. D. L. Patton and R. C. Advincula, Macromolecules, 2006, 39, 8674-8683. 18. S. Magens, M. Ertelt, A. Jatsch and B. Plietker, Org. Lett., 2008, 10, 53-56. 19. S. De Sarkar and A. Studer, Angew. Chem. Int. Ed., 2010, 49, 9266-9269.

Date post:	11-Mar-2020
Category:	Documents
Upload:	others
View:	1 times
Download:	0 times

Table of Contents - Royal Society of Chemistry · standard;1H NMR at δ 7.26 ppm and 13C NMR at δ...

Documents