ꢀꢀꢀꢁ
640ꢀ ꢀC. Weber et al.: A short synthesis of pyridines from deprotonated α-aminonitriles
(NCH2CHꢀ=ꢀCH2), 131.1 (C-4), 128.9 (Ph-C-3,5), 128.7 (Ph-C-4), (288.4). – 1H NMR, COSY (300 MHz, CDCl3), characteristic
126.1 (Ph-C-2,6), 121.7 (C-5), 120.3 (CN), 116.5 (NCH2CHꢀ=ꢀCH2), signals of diastereomer A: δ (ppm) ꢀ=ꢀ 7.71–7.64 (m, 2H, 2-Ph-
64.0 (C-2). 48.3 (C-3), 47.5 (NCH2). – IR (ATR): v (cm−1) ꢀ=ꢀ 3324, 2,6-H), 7.44–7.12 (m, 8H, 2-Ph-3,4,5-H, 1′-Ph), 5.89–5.66 (m,
3081, 2983, 2917, 2843, 1643, 1447, 1117, 993, 922, 762, 699. 1H, 4-H), 5.64 (ddd, J ꢀ=ꢀ 17.1, 10.1, 7.1 Hz, 1H, 2′-H), 5.28–5.13
+
– MS (ESI): m/z (%) ꢀ=ꢀ 186.3 (100) [M–CN−] . – HRMS ((+)- (m, 2H, 5-H), 5.05 (dt, J ꢀ=ꢀ 17.1, 1.2 Hz, 1H, 3′-H), 4.80 (dt,
+
ESI): m/z ꢀ=ꢀ 186.1283 (calcd. 186.1283 for C13H16N, [M–CN−] ). J ꢀ=ꢀ 10.1, 1.2 Hz, 1H, 3′-H), 4.47 (dt, J ꢀ=ꢀ 7.1, 1.2 Hz, 1H, 1′-H),
2.67–2.54 (m, 2H, 3-H), 2.23 (s br, 1H, NH). Characteristic
signals of diastereomer B: δ (ppm) ꢀ=ꢀ 7.55–7.47 (m, 2H, 2-Ph-
2,6-H), 7.44–7.12 (m, 8H, 2-Ph-3,4,5-H, 1′-Ph), 6.08 (ddd, J ꢀ=ꢀ
17.2, 10.2, 7.2 Hz, 1H, 2′-H), 5.89–5.66 (m, 1H, 4-H), 5.28–5.13
(m, 3H, 5-H, 3′-Ha), 5.14 (dt, J ꢀ=ꢀ 17.2, 1.2 Hz, 1H, 3′-Hb), 4.33
4.12 Phenyl[(1-phenylprop-2-en-1-yl)amino]
acetonitrile (27)
This compound was prepared as described for 19 using (dt, J ꢀ=ꢀ 7.2, 1.2 Hz, 1H, 1′-H), 2.72 (dt, J ꢀ=ꢀ 7.1, 1.1 Hz, 2H, 3-H),
13
benzaldehyde (3.25 mL, 32.1 mmol, 1.0 eq) and 1-phenyl- 2.23 (s br, 1H, NH). – C NMR, HSQC, HMBC (75.5 MHz,
prop-2-en-1-amine (4.28 g, 32.1 mmol, 1.0 eq) in methanol CDCl3): δ (ppm) ꢀ=ꢀ 142.5 (1′-Ph-C-1 A), 142.3 (1′-Ph-C-1 B),
(70 mL), potassium cyanide (3.13 g, 48.1 mmol, 1.5 eq) and 140.4 (C-2′ A), 139.9 (C-2′ B), 139.4 (2-Ph-C-1 A), 138.0 (2-Ph-
acetic acid (2.75 mL, 48.1 mmol, 1.5 eq) to yield 27 as a red C-1 B), 131.2 (C-4 A), 131.2 (C-4 B), 128.8 (CAr), 128.7 (CAr),
oil (7.50 g, 30.2 mmol, 94%). The compound was isolated 128.6 (CAr), 128.5 (2C, CAr), 128.3 (CAr), 127.7 (CAr), 127.4 (2C,
as 1:1 mixture of two diastereomers A and B. – Rf ꢀ=ꢀ 0.46 CAr), 127.1 (CAr), 126.6 (2C, 2-Ph-C-2,6 A+B), 121.7 (2C, C-5
1
(hexanes-EtOAc 10:1). C17H16N2 (248.3). – H NMR, COSY A+B), 120.9 (CN, B), 119.9 (CN, A), 116.6 (C-3′ B), 115.1 (C-
(300 MHz, CDCl3), characteristic signals of diastereomer 3′ B), 63.8 (C-2 B), 63.5 (C-2 A), 63.3 (C-1′ A), 62.1 (C-1′ B),
A: δ (ppm) ꢀ=ꢀ 7.61–7.44 (m, 4H, 2-Ph-2,6-H, 1′-Ph-2,6-H), 48.8, 48.7 (C-3 A+B). – As a mixture of two diastereomers
7.48–7.26 (m, 6H, 2-Ph-3,4,5-H, 1′-Ph-3,4,5-H), 5.98–5.86 (m, A and B. – IR (ATR): v (cm−1) ꢀ=ꢀ 3322, 3062, 2981, 2225, 1639,
1H, 2′-H), 5.32 (dt, J ꢀ=ꢀ 17.1, 1.2 Hz, 1H, 3′-H), 5.15 (dt, J ꢀ=ꢀ 10.2, 1491, 1449, 1106, 924, 761, 701. – MS (ESI): m/z (%) ꢀ=ꢀ 289.1
+
+
1.1 Hz, 1H, 3′-H), 4.86 (d, J ꢀ=ꢀ 9.9 Hz, 1H, 2-H), 4.59 (d, J ꢀ=ꢀ 8.0 (8) [M+H] , 262.1 (100) [M–CN−] . – HRMS ((+)-ESI): m/z ꢀ=ꢀ
Hz, 1H, 1′-H), 2.02–1.77 (m, 1H, NH). Characteristic signals 262.1589 (calcd. 262.1596 for C19H20N, [M–CN−] ).
+
of diastereomer B: δ (ppm) ꢀ=ꢀ 7.61–7.44 (m, 2H, 2-Ph-2,6-H),
7.48–7.26 (m, 8H, 2-Ph-3,4,5-H, 1′-Ph-3,4,5-H, 1′-Ph-2,6-H),
6.01 (ddd, J ꢀ=ꢀ 17.1, 10.1, 7.0 Hz, 1H, 2′-H), 5.54 (dt, J ꢀ=ꢀ 17.1, 4.14 2-Phenylpyridine (22)
1.2 Hz, 1H, 3′-H), 5.29 (ddd, J ꢀ=ꢀ 10.1, 1.3, 0.5 Hz, 1H, 3′-H),
4.64 (d, J ꢀ=ꢀ 7.0 Hz, 1H, 1′-H), 4.46 (d, J ꢀ=ꢀ 9.9 Hz, 1H, 2-H), A solution of compound 21 (45 mg, 0.21 mmol, 1.0 eq) in
2.02–1.77 (m, 1H, NH). – 13C NMR, HSQC, HMBC (75.5 MHz, degassed dry CH2Cl2 (36 mL) was added to a solution of
CDCl3): δ (ppm) ꢀ=ꢀ 141.5 (1′-Ph-C-1 A), 140.3 (1′-Ph-C-1 B), Grubbs’ second generation metathesis catalyst (76; 18 mg,
139.9 (C-2′ B), 138.8 (C-2′ A), 135.1 (2C, 2-Ph-C-1 A+B), 129.1 0.021 mmol, 10 mol–%) in degassed dry CH2Cl2 (0.91 mL)
(4C, CAR), 128.9 (CAR), 128.2 (CAR), 128.1 (CAR), 127.8 (CAR), under an argon atmosphere. The mixture was stirred at
127.5 (CAR), 127.4 (CAR), 127.3 (CAR), 119.0 (CN, A), 118.9 (CN, ambient temperature for 18 h before the solvent was evap-
B), 117.9 (C-3′, B), 116.1 (C-3′, A), 64.8 (C-1′, B), 64.6 (C-1′, A), orated under reduced pressure. The crude product was
52.3 (C-2, A), 51.9 (C-2, B). – As a mixture of two diastere- purified by column chromatography (SiO2, Cy-EtOAc 20:1)
omers A and B. – IR (ATR): v (cm−1) ꢀ=ꢀ – 3314, 3063, 3031, to obtain 22 as a colorless oil (16 mg, 0.10 mmol, 48%).
1602, 1494, 1452, 1275, 992, 697, 650. – MS (ESI): m/z (%) ꢀ=ꢀ – Rf ꢀ=ꢀ 0.42 (Cy-EtOAc 4:1). C11H9N (155.0). – 1H NMR, COSY
222.0 (100) [M–CN−] . – HRMS ((+)-ESI): m/z ꢀ=ꢀ 222.1290 (400 MHz, CDCl3): δ (ppm) ꢀ=ꢀ 8.72–8.70 (m, 1H, 6-H), 8.02–
+
+
(calcd. 222.1283 for C16H16N, [M–CN−] ).
7.97 (m, 2H, Ph-2,6-H), 7.79–7.73 (m, 2H, 3,4-H), 7.51–7.46 (m,
2H, Ph-3,5-H), 7.45–7.40 (m, 1H, Ph-4-H), 7.26–7.23 (m, 1H,
5-H). The spectroscopic data are in accordance with the
literature [23].
4.13 2-Phenyl-2-[(1-phenylprop-2-en-1-yl)
amino]pent-4-enenitrile (28)
This compound was prepared as described for 20 using 4.15 2,6-Diphenylpyridine (29)
Compound 27 (585 mg, 2.36 mmol, 1.0 eq), KHMDS
(593 mg, 3.06 mmol, 1.3 eq) and allyl bromide (0.21 mL, The title compound was prepared as described for 22 using
2.43 mmol, 1.0 eq) to yield 28 as a yellow oil (543 mg, compound 28 (67 mg, 0.23 mmol, 1.0 eq) and Grubbs’
1.80 mmol, 76%). – Rf ꢀ=ꢀ 0.54 (hexanes-EtOAc 10:1). C20H20N2 second generation metathesis catalyst (76; 15.3 mg,
Unauthenticated
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