Vol. 28, No. 5 (2016)
o-Eugenol: A Versatile Molecule for Production of Polyfunctional Alkenes via Organometallic Catalysis 961
2 equiv.), 1.5 mL of solvent and then closed by a rubber septum.
Another dry and degassed Schlenk tube was loaded under
argon with 6.0-7.6 mg of Hoveyda catalyst II (12 × 10-3 mmol,
2 mol %), 10 µL of dodecane as internal standard and 0.5 mL
of solvent. The ruthenium catalyst was then taken by a syringe
and was slowly added into the first Schlenk tube through the
septum by means of a syringe-pump during 2 h.After addition,
the reaction mixture was stirred at 100 °C for additional 3 h.
After solvent evaporation, the products were purified by column
chromatography on silica gel using of EtOAc/petroleum ether
mixtures.
General procedure for the cross-metathesis reactions
with acrylamide: A dry and degassed Schlenk tube was loaded
under argon with 125-157 mg of o-eugenol (0.76 mmol, 1.25
equiv.), 2.5-3.3 mg of para-benzoquinone (~ 22-30 × 10-3
mmol, 5 mol %), 43 mg of acrylamide (0.6 mmol, 1 equiv.),
10 µL of dodecane as internal standard and 1.5 mL of solvent
and then closed by a rubber septum.Another dry and degassed
Schlenk tube was loaded under argon with 7.6 mg of Hoveyda
catalyst (12 × 10-3 mmol, 2 mol %), 10 µL of dodecane as
internal standard and 0.5 mL of solvent. The ruthenium catalyst
was then taken by a syringe and was slowly added into the
first Schlenk tube through the septum by means of a syringe-
pump during 2 h.After addition, the reaction mixture was stirred
at 80 °C for additional time under the mentioned conditions.
After solvent evaporation, the products were purified by column
chromatography on basic alumina gel using of EtOAc/petro-
leum ether mixtures.
(E)-methyl 4-(2-hydroxy-3-methoxyphenyl)but-2-
enoate (5): Yield = 60 %; 1H NMR (400 MHz, CDCl3, ppm):
3.54 (d, J = 6.4 Hz, 2H, H1’), 3.70 (s, 3H, OCH3), 3.88 (s, 3H,
COOCH3), 5.70 (s, 1H, OH), 5.81 (d, J = 15.6 Hz, 1H, H3’),
6.70 (d, J = 6.8 Hz, 1Har, H6), 6.76-6.79 (m, 2Har, H4,5), 7.09-
7.16 (m, 1H, H2’). 13C NMR (100 MHz, CDCl3, ppm): 32.3
(C1’), 51.3 (OCH3), 55.9 (COOCH3), 109.1 (CH), 119.5 (C4),
121.4 (C5), 122.3 (C6), 123.4 (C1), 143.5 (C2), 146.4 (C3), 147.1
(C3’), 167.0 (C=O). Anal. calcd. for C12H14O4: C, 64.853 %;
H, 6.350 %. Found: C, 64.8; H, 6.3; HRMS (ESI): [M + Na]+
calculated for (C12H14O4Na) = m/z 245.0789. Measured: m/z
245.0787; C12H14O4: Theor. C 64.85, H 6.35 Exp. C 64.84, H
6.37.
4-(2-Hydroxy-3-methoxy-phenyl) but-2-enenitrile (6):
Yield = 65 %; 1H NMR (400 MHz, CDCl3, ppm): 3.54, 3.76
(2d, J = 6.0 Hz, 7.2 Hz, 2H, H1’, cis + trans), 3.89 (s, 3H,
OCH3), 5.29, 5.36 (2d, J = 16.0 Hz, J = 10.8 Hz, 1H, H3’, cis
+ trans), 5.78, 5.80 (2s, 1H, OH, cis + trans), 6.64-6.70 (m,
1H, H2’), 6.78-6.80 (m, 3Har, H4,5,6). 13C NMR (100 MHz,
CDCl3, ppm): 32.3, 33.4 (C1’, cis + trans), 55.9 (OCH3), 99.3,
100.1 (C3’, cis + trans), 109.4, 109.5 (CH, cis + trans),116.0,
117.5 (CN, cis + trans), 119.7 (C4), 122.0, 122.2 (C5, cis +
trans), 122.6 (C1), 143.5 (C2), 146.4 (C3), 152.4, 153.4 (C2,
cis + trans).Anal. calcd. for C11H11O2N: C, 69.826 %; H, 5.860
%. Found: C, 69.8; H, 5.8; HRMS (ESI): [M + Na]+ calculated
for (C11H11NO2Na) = m/z 212.0687. Measured: m/z 212.0688;
C11H11NO2: Theor. C 69.83, H 5.86, N 7.4 Exp. C 69.29, H
5.76, N 7.03.
3.49 (d, J = 7.6 Hz, 2H, H1’), 3.82 (s, 3H, OCH3), 5.88 (s, 1H,
H3’), 6.24-6.26 (m, 1H, OH), 6.62 (s, 1H, H2’), 6.73 (d, J = 8.0
Hz, 1Har, H6), 6.80 (dd, 1Har, J = 7.6 Hz, J = 7.6 Hz, H5),
6.92(d, 1H, J = 8.0 Hz, H4). 13C NMR (100 MHz, Methanol-
d4, ppm): 33.1 (C1’), 56.2 (OCH3), 110.7 (C4), 120.1 (C5), 123.0
(C6), 124.2 (C3’), 125.6 (C1), 144.9 (C2’), 145.2 (C2), 148.6
(C3), 171.0 (CONH2). Anal. calcd. for C11H13O3: C, 68.377 %;
H, 6.782 %. Found: C, 68.3 H, 6.7; HRMS (ESI): [M + Na]+
calculated for (C11H13NO3Na) = m/z 230.0793. Measured: m/z
230.0796
1-Allyl-2-(allyloxy)-3-methoxybenzene (8): A mixture
of o-eugenol (1, 16.4 g, 0.1 mol), NaOH (6 g, 0.15 mol),
dichloromethane (50 mL), CTAB (1.21 × 102 mM) and distilled
water (50 mL) were placed in 500 mL round bottom flask.
Allyl bromide (24.2 g, 0.2 mol) was added drop wise and the
mixture was then stirred at room temperature for 5 h. After
completion, the organic layer was separated and aqueous layer
was extracted with dichloromethane (2 × 20 mL). The
combined organic phase was washed with distilled water (2 ×
50 mL), dried with anhydrous Na2SO4 and concentrated to
give compound (2) (16.60 g, 81.10 %) as yellowish liquid. IR
(ATR) νmax, cm-1): 3078,2908-2839, 1843, 1589 and 1512,
1
1458, 1419, 1226 and 1141, 995, 918, 856 and 739. H
NMR spectrum (500 MHz, CDCl3): δ 6.71-6.74 ppm (3H, m,
ArH), 5.95-5.97 (2H, m, =CH), 5.26-5.32 (2H, m, =CH2), 5.05
(2H, t, J = 15.6 Hz, =CH2), 4.57 (2H,d, J = 15.6 Hz, CH2O),
3.81 (3H, s, OCH3) and 3.31 (2H, d, J = 8.6 Hz, CH2). 13C
NMR spectrum (125 MHz,CDCl3,): δ 39.80 (CH2), 55.81
(OCH3), 69.96 (OCH2),115.61 and 117.73 9 (CH2=), 133.55
and 137.62 (=CH), 112.20, 113.58, 120.33, 133.03, 146.30
and 149.36 (ArC). Mass spectrum (EI): m/z 204 (M, 40 %),163
(100), 135 (15), 103 (70), 91 (50), 77 (23), 41 (70). Anal.
calcd. for C13H16O2: C, 76.440 %; H, 7.895 %. Found: C, 76.4,
H, 7.8
(E)-Methyl 4-(2-methoxy-4-((E)-4-methoxy-4-oxobut-
1
2-enyl) phenoxy)but-2-enoate (9): Yield = 72 % H NMR
(400 MHz, CDCl3, ppm): 3.46 (d, 6.0 Hz, 2H, H1’), 3.72 (s,
3H, CH 3), 3.74 (s, 3H, CH3), 3.86 (s, 3H, CH3), 4.74-4.75
(m, 2H, CH2), 5.81 (d, J = 15.6 Hz, 1H, H3’), 6.18 (d, J = 15.6
Hz, 1H, H6), 6.66-6.68 (m, 2Har, H4,5), 6.77 (d, J = 8.4 Hz,
1Har, H6), 7.05-7.11 (m, 2H, CH, H2’,5’). 13C NMR (100 MHz,
CDCl3, ppm): 38.0 (C1’), 51.4 (CH3), 51.5 (CH3), 55.8 (CH),
67.7 (C4’), 112.5 (C4), 114.0 (C5), 120.7 (C6’), 121.7 (C6), 121.7
(C5), 131.3 (C1), 142.8 (C2), 146.2 (C3), 147.5 (C5’), 149.6 (C2),
166.3 (COOCH3), 166. 8 (COOCH3).Anal. calcd. for C16H18O6:
C, 62.737 %; H, 5.923 %. Found: C, 62.7, H, 5.9; HRMS
(ESI): [M + Na]+ calculated for (C17H20O6Na) = 343.1157.
Measured: 343.1160; C17H20O6: Theor. C 63.74, H 6.29 Exp.
C 64.01, H 6.26
Poly bis-allyl-benzene o-eugenol (10): The product was
obtained after decanting into cold methanol to obtain 187 g of
polymer having the following characteristics: Mn: 2959
(g/mol); Mw: 8145; PDi: 2.7526 determined by gel permeation
chromatography GPC (calibrated against polystyrene in
1
chloro-form). H NMR (400 MHz, CDCl3, ppm): 3.32 (bd,
13.2 Hz, 2H, CH2), 3.82 (s, 3H, CH3), 4.57 (bd, 2H, CH2),
5.65-6.08 (m, 2H, CH), 6.65-6.70 (m, 2Har, CH), 6.78 (d, 6.4
Hz, 1Har, CH).
(E)-4-(2-Hydroxy-3-methoxyphenyl) but-2-enamide
1
(7): Yield = 56 %; H NMR (400 MHz, Methanol-d4, ppm):