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Hz, J = 8.1 Hz), 7.15 (dd, 1H, J = 7.3 Hz, J = 8.1 Hz), 4.27 (sept, 2H, J
= 6.1 Hz), 1.30 (d, 6H, J = 6.1 Hz), 1.14 (d, 6H, J = 6.1 Hz); 13C
NMR (125 MHz, CDCl3) δ 138.8, 136.8, 134.8, 132.4, 129.8, 129.6,
126.5, 125.6, 99.5, 66.7, 24.1; HRMS (ESI) for C16H2111BIO2 (M + H)
calcd. 383.06767, found 383.06693.
Diisopropyl-8-iodonaphthalen-1-yl-1-boronate was dissolved in
methanol, and the solvent was evaporated under reduced pressure
three times. After concentrating the mixture under reduced pressure, a
drop of water was added to the residue, and the desired product was
isolated as colorless crystals in 73% yield (0.55 g): mp 128−131 °C; IR
(Microscope, cm−1) 3314, 3049, 1601, 1368, 1216, 813, 765; 1H NMR
(400 MHz, DMSO-d6) δ 8.15 (dd, 1H, J = 1.3 Hz, J = 7.3 Hz), 8.10 (s,
2H), 7.94 (dd, 1H, J = 1.2 Hz, J = 8.3 Hz), 7.84 (dd, 1H, J = 1.9 Hz, J
= 7.7 Hz), 7.49 (m, 2H), 7.20 (dd, 1H, J = 7.3 Hz, J = 8.0 Hz); 13C
NMR (125 MHz, DMSO-d6) δ 138.4, 135.7, 134.2, 131.8, 129.3,
128.7, 126.5, 125.5, 100.1; HRMS (ESI) for C10H811BClIO2 (M + Cl)
calcd. 332.93579, found 332.93511.
h). The product’s H and 13C NMR characterization data matched
data found in the literature.68
N-Hexylhexadecanamide (Table 5, Entry 6). The title compound
was prepared using the general procedure for the boronic acid
catalyzed amidations, and isolated as a white solid (70% yield using 4a
and 95% yield (161 mg) using 4f after 6 h): mp 62−64 °C; IR
(Microscope, cm−1) 3292, 2918, 2872, 2849, 1638; H NMR (500
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MHz, CDCl3) δ 5.74 (br s, 1H), 3.20 (q, J = 7.0 Hz, 2H), 2.13 (t, J =
7.3 Hz, 2H), 1.64−1.54 (m, 2H), 1.50−1.40 (m, 2H), 1.32−1.18 (m,
32H), 0.90−0.82 (m, 6H); 13C NMR (125 MHz, CDCl3) δ 173.1,
39.5, 36.9, 31.9, 31.5, 29.7, 29.7, 29.7, 29.6 (3C), 29.6, 29.5, 29.4, 29.3,
29.3, 26.6, 25.8, 22.7, 22.5, 24.1, 14.0; HRMS (ESI) for C22H46NO (M
+ H) calcd. 340.3574, found 340.3574; for C22H45NNaO (M + Na)
calcd. 362.3393, found 362.3394.
2-Phenyl-1-(pyrrolidin-1-yl)ethanone (Table 5, Entry 7). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations (66% yield using 4a and 91% yield (86 mg)
using 4f after 6 h). The product’s H and 13C NMR characterization
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Typical General Procedure for Boronic Acid Catalyzed
Amidations. N-Benzyl-2-phenylacetamide, with Catalyst Recovery
(Table 5, Entry 1). Into a 25 mL round-bottom flask equipped with a
magnetic stir bar was added phenylacetic acid (75 mg, 0.55 mmol, 1.1
equiv), 2-iodo-5-methoxyphenylboronic acid 4f (13.9 mg, 0.05 mmol,
10 mol %) and 1 g of activated molecular sieves 4 Å. Dichloromethane
(7 mL) was added, and the mixture was stirred vigorously for 10 min.
Then, benzylamine (55 μL, 0.5 mmol, 1 equiv) was added (in order to
get reproducible results, it is necessary to use a gastight 100 μL
syringe). The resulting mixture was stirred for 2 h under vigorous
stirring at room temperature (24−25 °C). The reaction mixture was
filtered through a pad of Celite 545; the filtrate was washed with
aqueous acidic solution (pH = 3), aqueous basic solution (pH = 11)
and brine. The organic layer was collected, dried over anhydrous
Na2SO4, filtered and evaporated to yield the title compound (71%
using 4a, 98% (110 mg) using 4f, 41% using 1, 3% using 2) as a pure
product (the catalyst can be recovered in up to 90% yield by
acidification of the aqueous basic solution to pH 6−7 and extraction
data matched data found in the literature.69
2-Phenyl-1-(piperidin-1-yl)ethanone (Table 5, Entry 8). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations (55% yield using 4a and 70% yield (71 mg)
using 4f after 48 h). The product’s 1H and 13C NMR characterization
data matched data found in the literature.70
N-Benzyl-4-iodobenzamide (Table 5, Entry 10). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations (22% yield using 20 mol % of 4a and 30%
yield (51 mg) using 20 mol % of 4f at 50 °C in toluene after 48 h).
The product’s H and 13C NMR characterization data matched data
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found in the literature.71
N-Benzylfuran-2-carboxamide (Table 5, Entry 11). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations and isolated as a light yellow solid (38%
yield using 20 mol % of 4a and 53% yield (53 mg) using 20 mol % of
4f at 50 °C in DCM after 48 h): mp 111−113 °C; IR (Microscope,
cm−1) 3302, 3063, 3031, 2926, 1649, 1594, 1526, 1475; 1H NMR (300
MHz, CDCl3) δ 7.42 (dd, J = 0.7, 1.7 Hz, 1H), 7.38−7.26 (m, 5H),
7.15 (dd, J = 0.7, 3.5 Hz, 1H), 6.65 (br s, 1H), 6.51 (dd, J = 1.8, 3.5
Hz, 1H), 4.62 (d, J = 5.9 Hz, 2H); 13C NMR (125 MHz, CDCl3) δ
158.3, 147.9, 143.9, 138.0, 128.8, 127.9, 127.7, 114.4, 112.2, 43.2;
HRMS (ESI) for C12H12NO2 (M + H) calcd. 202.0863, found
202.0863; for C12H11NNaO2 (M + Na) calcd. 224.0682, found
224.0677. (Note that the product was described in the literature,72 but
the above NMR data is of higher definition.)
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with EtOAc (5×)). The product’s H and 13C NMR characterization
data matched data found in the literature.66,67
Preparation and Characterization of Amides (Table 5). N-(2-
Methylpropyl)-2,2-diphenylacetamide (Table 5, Entry 2). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations, and isolated as a light yellow solid (44%
yield using 4a, 58% (78 mg) using 4f, 17% using 1 and 3% using 2
after 6 h): mp 107−109 °C; IR (Microscope cm−1) 3265, 3085, 2959,
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2929, 2869, 1949, 1881, 1640, 1560; H NMR (300 MHz, CDCl3) δ
N-Benzylfuran-3-carboxamide (Table 5, Entry 12). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations (32% yield using 20 mol % of 4a and 44%
yield (44 mg) using 20 mol % of 4f at 50 °C in DCM after 48 h): mp
7.40−7.20 (m, 10H), 5.96 (br s, 1H), 4.97 (s, 1H), 3.09 (dd, J = 6.1
Hz, J = 6.7 Hz, 2H), 1.73 (sept, J = 6.6 Hz, 1H), 0.83 (d, J = 6.7 Hz,
6H); 13C NMR (125 MHz, CDCl3) δ 172.0, 139.7, 128.9, 128.7,
127.2, 59.2, 47.1, 28.4, 20.0; HRMS (ESI) for C18H22NO (M + H)
calcd. 268.1696, found 268.1692; for C18H21NNaO (M + Na) calcd.
290.1515, found 290.151.
120−122 °C. The product’s H and 13C NMR and MS character-
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ization data matched data found in the literature.73,74
N-Benzylthiophene-2-carboxamide (Table 5, Entry 13). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations (51% yield using 20 mol % of 4a and 73%
yield (79 mg) using 20 mol % of 4f at 50 °C in DCM after 48 h). The
N-Hexyl-2-phenylacetamide (Table 5, Entry 3). The title
compound was prepared using the general procedure for the boronic
acid catalyzed amidations (60% yield using 4a and 85% yield (93 mg)
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using 4f after 6 h). The product’s H and 13C NMR characterization
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product’s H and 13C NMR characterization data matched data found
data matched data found in the literature.66
in the literature.75
N-(2-Methoxypropyl)-2-phenylacetamide (Table 5, Entry 4). The
title compound was prepared using the general procedure for the
boronic acid catalyzed amidations, and isolated as a brown solid (68%
yield using 4a and 90% yield (93 mg) using 4f after 2 h): mp 67−69
°C; IR (Microscope cm−1) 3278, 3085, 2958, 2926, 2871, 1956, 1643,
1561; 1H NMR (300 MHz, CDCl3) δ 7.30−7.20 (m, 5H), 5.98 (br s,
1H), 3.52 (s, 2H), 2.99 (dd, J = 6.1 Hz, J = 6.8 Hz, 2H), 1.66 (sept, J =
6.7 Hz, 1H), 0.78 (d, J = 6.7 Hz, 6H); 13C NMR (125 MHz, CDCl3) δ
171.1, 135.3, 129.3, 128.8, 127.1, 46.9, 43.7, 28.4, 20.0; HRMS (ESI)
for C12H18NO (M + H) calcd. 192.1383, found 192.138; for
C12H17NNaO (M + Na) calcd. 214.1202, found 214.1197.
N-[2-(4-Hydroxyphenyl)ethyl]-2-phenylacetamide (Table 5, Entry
14). The title compound was prepared using the general procedure for
the boronic acid catalyzed amidations (45% yield using 4a and 70%
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yield (89 mg) using 4f after 24 h): H NMR (500 MHz, CDCl3) δ
8.85 (br s, 1H), 7.30−7.24 (m, 2H), 7.23−7.18 (m, 3H), 6.99 (t, J =
5.6 Hz, 1H), 6.91−6.87 (m, 2H), 6.74−6.70 (m, 2H), 3.45 (s, 2H),
3.34 (q, J = 6.7 Hz, 2H), 2.64 (t, J = 7.2 Hz, 2H); 13C NMR (125
MHz, CDCl3) δ 171.3, 155.8, 135.7, 129.7, 129.6, 129.3, 128.7, 126.9,
115.6, 43.4, 41.3, 4.7. (Note that the product was described in the
literature,76 but no 13C NMR data was reported.)
2-Phenyl-N-(pyridine-2-ylmethyl)acetamide (Table 5, Entry 15).
The title compound was prepared using the general procedure for the
boronic acid catalyzed amidations, and isolated as a white solid (80%
yield using 20 mol % of 4a and 99% yield (112 mg) using 20 mol % of
N-Benzylhexanamide (Table 5, Entry 5). The title compound was
prepared using the general procedure for the boronic acid catalyzed
amidations (80% yield using 4a and 92% yield (94 mg) using 4f after 6
M
dx.doi.org/10.1021/jo3013258 | J. Org. Chem. XXXX, XXX, XXX−XXX