590
J. Terauchi, D. P. Curran / Tetrahedron: Asymmetry 14 (2003) 587–592
134 (80), 91 (100); HRMS (EI) m/z calcd for C18H21NO
(m, 2H), 5.15 (d, 1H, J=10.0 Hz), 5.92–6.06 (m, 1H),
6.85 (dd, 1H, J=1.5, 7.8 Hz), 7.10–7.32 (m, 6H), 7.38
(dt, 1H, J=1.6, 7.7 Hz), 7.64 (dd, 1H, J=1.5, 8.1 Hz);
13C NMR (75 MHz, CDCl3, l) 32.25, 36.16, 41.80,
54.21, 118.65, 126.56, 126.66, 128.20, 128.68, 129.37,
129.89, 132.41, 132.60, 135.04, 139.65, 146.28, 171.05;
LRMS (EI, 70 eV) m/z (rel. intens.) (M+1) 308 (4), 251
(M+): 267.1623, found: 267.1627.
4.2.2. N-(2-tert-Butylphenyl)acrylamide, 2b. Mp=140–
142°C; IR (thin film/NaCl/cm−1) 3207.4, 2963.3, 1652.1;
1H NMR (300 MHz, CDCl3, l) 1.43 (s, 9H), 5.81 (d,
1H, J=9.5 Hz), 6.23–6.50 (m, 2H), 7.13–7.33 (m, 3H),
7.43 (d, 1H, J=7.1 Hz), 7.65–7.73 (m, 1H); 13C NMR
(75 MHz, CDCl3, l) 30.63, 34.58, 126.39, 126.54,
126.72, 127.73, 128.28, 131.43, 134.86, 143.13, 164.03;
LRMS (EI, 70 eV) m/z (rel. intens.) (M+) 203 (28), 146
(100), 134 (55); HRMS m/z calcd for C13H17NO (M+):
203.1310, found: 203.1307.
(91), 216 (25), 132 (100), 117 (45), 91 (57), 65 (68), 57
+
(97); HRMS m/z calcd for C21H25NO (M ): 307.1936,
found: 307.1933; [h]2D3=+73.4 (c 1.11, CHCl3).
4.3.2. N-Allyl-N-(2-tert-butylphenyl)acrylamide, 3b. The
enantiomeric excess was determined to be 43% by
HPLC analysis (hexane/2-propanol=90/10), 0.5 ml/
min, 0.40 kpsi, retention times: 17.2 min (dominant)
and 18.6 min. IR (thin film/NaCl/cm−1) 2962.9, 1659.4,
1406.0, 1255.0, 982.9, 759.1; 1H NMR (300 MHz,
CDCl3, l) 1.37 (s, 9H), 3.43 (dd, 1H, J=8.1, 14.1 Hz),
5.01 (dd, 1H, J=5.1, 14.1 Hz), 5.12 (dd, 1H, J=1.0,
17.1 Hz), 5.18 (d, 1H, J=9.9 Hz), 5.49 (dd, 1H, J=2.0,
10.2 Hz), 5.92 (dd, 1H, J=10.3, 16.8 Hz), 5.99–6.12 (m,
1H), 6.39 (dd, 1H, J=2.0, 16.8 Hz), 6.95 (d, 1H, J=7.7
Hz), 7.20 (t, 1H, J=7.5 Hz), 7.34 (t, 1H, J=7.6 Hz),
7.58 (d, 1H, J=8.1 Hz); 13C NMR (75 MHz, CDCl3, l)
32.26, 36.19, 54.42, 118.93, 126.93, 127.65, 128.76,
129.10, 129.82, 132.35, 132.65, 139.47, 146.99, 165.82;
LRMS (EI, 70 eV) m/z (rel. intens.) (M+) 243 (3), 186
(100), 132 (54), 55 (78); HRMS m/z calcd for
C16H21NO (M +): 243.1623, found: 243.1626; [h]2D3=
+54.5 (c 0.415, CHCl3).
4.2.3. N-(2-tert-Butylphenyl)benzamide, 2c. Mp=189–
191°C; IR (thin film/NaCl/cm−1) 3339.5, 1646.0, 1516.5,
1481.6, 1290.7, 759.1, 710.2; 1H NMR (300 MHz,
CDCl3, l) 1.47 (s, 9H), 7.17–7.33 (m, 2H), 7.45 (d, 1H,
J=7.8 Hz), 7.49–7.67 (m, 3H), 7.76 (d, 1H, J=7.8 Hz),
7.91 (br s, 1H), 7.92 (d, 2H, J=7.7 Hz)); 13C NMR (75
MHz, CDCl3, l) 30.71, 34.60, 126.28, 126.58, 126.84,
126.94, 128.06, 128.80, 131.73, 134.83, 135.24, 142.86,
165.67; LRMS (EI, 70 eV) m/z (rel. intens.) (M+) 253
(15), 196 (100), 105 (65), 91 (12), 77 (69); HRMS
+
(M+1)=206 (5), (M −t-Bu )=148 (100), calcd mass
for: (M ) C17H19NO: 253.1467, found: 253.1465.
4.2.4. N-(2-tert-Butylphenyl)pivalamide, 2d. Mp=122–
123°C; IR (thin film/NaCl/cm−1) 3289.0, 2955.5,
1
1650.2, 1503.4, 755.2; H NMR (300 MHz, CDCl3, l)
1.47 (s, 9H), 1.54 (s, 9H), 7.26 (dt, 1H, J=1.5, 7.6 Hz),
7.34 (dt, 1H, J=1.7, 7.6 Hz), 7.50 (dd, 1H, J=1.6, 7.9
Hz), 7.52 (br s, 1H), 7.76 (dd, 1H, J=1.6, 7.9 Hz); 13C
NMR (75 MHz, CDCl3, l) 27.78, 30.71, 34.63, 36.56,
125.90, 126.55, 126.86, 127.79, 135.70, 142.24, 176.39;
LRMS (EI, 70 eV) m/z (rel. intens.) (M+) 233 (24), 176
(100); HRMS m/z calcd for C15H23NO (M+.): 233.1780,
found: 233.1779.
4.3.3. N-Allyl-N-(2-tert-butylphenyl)benzamide, 3c. The
enantiomeric excess was determined to be 36% by
HPLC analysis (hexane/2-propanol=90/10), 2.0 ml/
min, 1.95 kpsi, retention times: 6.9 and 13.2 min (dom-
inant). IR (thin film/NaCl/cm−1) 2955.1, 1636.8, 1488.0,
1
1438.8, 1384.1, 1302.8; H NMR (300 MHz, CDCl3, l)
1.26 (s, 9H (maj)), 1.50 (s, 9H (min)), 3.56 (dd, 1H
(maj), J=8.0, 14.0 Hz), 3.76 (dd, 1H (min), J=7.6, 15.2
Hz), 4.13 (q, 1H (min), J=7.1 Hz), 4.52 (dd, 1H (min),
J=5.8, 15.9 Hz), 4.80 (d, 1H (min), J=16.9 Hz),
5.00–5.27 (m, 3H (maj)), 5.75–5.89 (m, 1H (min)),
6.07–6.24 (m, 1H (maj)), 7.06–7.17 (m, 4H), 7.18–7.34
(m, 4H), 7.43–7.49 (m, 2H), 7.56–7.62 (m, 1H); 13C
NMR (75 MHz, CDCl3, l) 31.94, 32.37, 36.31, 56.08,
118.79, 126.33, 126.83, 127.52, 128.30, 128.64, 129.40,
129.74, 130.72, 132.58, 132.90, 136.00, 140.08, 146.13,
168.88; LRMS (EI, 70 eV) m/z (rel. intens.) (M+1) 293
(3), 236 (90), 195 (19), 132 (28), 105 (100), 91 (20), 77
(87), 69 (25), 57(33); HRMS m/z calcd for C20H23NO
(M+): 293.1780, found: 293.1784; [h]2D3=+12.4 (c 0.41,
CHCl3).
4.3. General method for asymmetric allylation of
anilides 2
A mixture of [Pd(p-allyl)Cl]2 (1.8 mg, 4.9 mmol) and
(S)-BINAP (6.8 mg, 10.9 mmol) in toluene (1 ml) was
stirred for 30 min at room temperature. Allyl acetate
(33 ml, 0.306 mmol) was added to the solution. After 10
min, the solution was added to a suspension of anilide
2 (0.2 mmol) and BuLi (1.6 M in hexane, 0.15 ml, 0.24
mmol) in toluene (2 ml) at −40°C. The reaction was
quenched by water after the complete consumption of 2
or 24 h. The mixture was extracted with ether (2×50
ml). The organic layer was washed with brine, dried
over MgSO4, and evaporated under reduced pressure.
The residue was purified by column chromatography
on silica gel (EtOAc/hexane), giving 5.
4.3.4. N-Allyl-N-(2-tert-butylphenyl)pivamide, 3d. The
enantiomeric excess was determined to 9% by HPLC
analysis (hexane/2-propanol=90/10), 0.5 ml/min, 0.40
kpsi, retention times: 9.9 min (dominant) and 11.0 min.
mp=77–80°C; IR (thin film/NaCl/cm−1) 2961.4, 1630.3,
4.3.1.
N-Allyl-N-(2-tert-butylphenyl)phenylacetamide,
3a. The enantiomeric excess was determined to be 53%
by HPLC analysis (hexane/2-propanol=90/10), 1.0 ml/
min, 0.84 kpsi, retention times: 17.6 and 21.9 min
(dominant): IR (thin film/NaCl/cm−1) 2961.3, 1657.3,
1486.9, 1438.1, 1389.2, 1256.5; 1H NMR (300 MHz,
CDCl3, l) 1.46 (s, 9H), 3.31–3.45 (m, 3H), 4.86–5.12
1
1481.7, 1364.4, 1198.7; H NMR (300 MHz, CDCl3, l)
1.02 (s, 9H), 1.41 (s, 9H), 3.12 (dd, 1H, J=7.9, 13.9
Hz), 5.02 (d, 1H, J=15.9 Hz), 5.14 (d, 1H, J=10.2 Hz),
5.89–6.07 (m, 1H), 6.97 (d, 1H, J=7.4 Hz), 7.13 (t, 1H,
J=7.5 Hz), 7.31 (t, 1H, J=7.2 Hz), 7.55 (d, 1H, J=8.1