(S)-(−)-N-(2′-Chloro-2′-phenylethyl)-2-pyridyl-carboxamide
(S)-(−)-(45). Trichlorosilane (367 μL, 3.6 mmol, 8.1 equiv.) was
added to a solution of oxazoline (S)-16 (100 mg, 0.45 mmol,
1.0 equiv.) in CH2Cl2 (5 mL) at 0 °C and the mixture was stirred
at room temperature overnight. The reaction was quenched with
satd NaHCO3 (aq) (10 mL) and the mixture was extracted with
CH2Cl2 (3 × 20 mL) and the combined organic extracts were
dried over MgSO4. Concentration under reduced pressure, fol-
lowed by purification via column chromatography on silica gel
(hexane–ethyl acetate, 1 : 1), gave (−)-45 (63 mg, 54%) as
a white solid: mp 74–75 °C (ethyl acetate–hexane); [α]D −45.3
(c 0.4, CHCl3); IR (KBr) ν 1523, 1656 (amide CvO), 2938
Ministry of Education and Science of Spain for a fellowship to
P. R.-L., the Loughborough University, the University of
Glasgow and Dr Alfred Bader for additional support. We
acknowledge COST-ORCA action (CM0905) for creating net-
working and exchange opportunities.
References
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(CH/CH2), 3034 (Ar-H), 3336, 3373 (amide N–H) cm−1
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1H NMR (400 MHz, CDCl3) δH 3.74–3.81 (m, 1H), 4.03–4.10
(m, 1H), 5.06 (dd, J = 9.2, 5.2 Hz, 1H), 7.25–7.41 (m, 6H), 7.78
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262 (M+˙{37Cl}, 3), 260 (M+˙{35Cl}, 10), 224 (10), 135 (100),
118 (15), 106 (90), 78 (98), 51 (18), 50 (4); HRMS (EI)
260.0714 and 262.0689 (C14H1335ClN2O requires 260.0716,
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1
(20 : 1): colourless oil; H-NMR (400 MHz, CDCl3) δH 1.30 (m,
d, J = 6.4 Hz, 6H, 2Me), 1.34 (M, d, J = 6.4 Hz, 6H, 2Me),
3.64 (m, s, 6H, 2OMe), 3.67 (M, s, 6H, 2OMe), 4.10 (m, q,
J = 6.4 Hz, 2H, 2CH), 4.16 (M, q, J = 6.4 Hz, 2H, 2CH), 6.71
(M, d, J = 8.4 Hz, 2H), 6.76 (m, d, J = 8.0 Hz, 2H), 6.82 (M, t,
J = 7.6, 2H), 6.96 (m, t, J = 7.2, 2H), 7.10 (M, td, J = 8.0, 1.6
Hz, 2H), 7.17 (m, td, J = 8.0, 1.6 Hz, 2H), 7.39 (M, dd, J = 7.6,
1.6 Hz, 2H), 7.50 (m, dd, J = 7.2, 1.6 Hz, 2H); 13C NMR
(100 MHz, CDCl3) δC 22.8 (2 × CH3), 25.4 (CH), 45.5 (CH2),
65.4 (CH), 79.7 (CH2), 123.9 (CH), 125.4 (CH), 136.6 (CH),
149.7 (CH), 162.5 (C), 165.1 (C); IR (CHCl3) ν 1216 (C–O),
3019 (Aryl C–H) cm−1; EI MS m/z (%) 286 (M+˙, 6), 271 (4),
178 (4), 151 (6) 135 (100), 105 (13), 84 (9), 49 (11); HRMS
(EI) 286.1569 (C18H22O3 requires 286.1568).
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Di(1-phenyl-1-buten-3-yl)ether (48).35 Obtained from the
reduction of 1m (Table 3, entry 13) as a 1 : 1 mixture of diastereo-
isomers by elution from silica gel as a less polar fraction than the
main product using a petroleum ether–AcOEt mixture (75 : 1):
1H-NMR (400 MHz, CDCl3) δH 1.26 and 1.28 (2 × d,
J = 6.4 Hz, 2 × 6H, 2 × 2Me), 4.10 and 4.16 (2 × m, 2 × 2H,
2 × 2CH3CH), 6.04 and 6.11 (2 × dd, 2 × J = 16.0, 7.6 Hz,
2 × 2H, 2 × 2CHCHv), 6.42 and 6.46 (2 × d, 2 × J = 16.0 Hz,
2 × 2H, 2 × 2PhCHv), 7.12–7.36 (m, 2 × 10H, 2 × 2Ph) in
agreement with literature data.35
Acknowledgements
We thank the EPSRC for grant No. GR/S87294/01, GSK and
EPSRC for an industrial CASE awards to A. J. P. S. L., the
4876 | Org. Biomol. Chem., 2012, 10, 4864–4877
This journal is © The Royal Society of Chemistry 2012