My PhD dissertation - Institut Fresnel

31 P NMR (acetone-d6) : δ = - 73.1 ppm.
77
C15H15O6P (322.25) calcd. C 55.91% H 4.69%
found C 55.85% H 4.65%.
2.3 Ethyl bis{N-[(1S)-1-phenylethyl]-1H-pyrrol-2-yl}phosphinite
and Other Pyrrole Derivatives
(+)-(1S)-N-(1-Phenylethyl)pyrrole (S-14): A suspension of (S)-(-)-α-methylbenzylamine
(38 mL, 36 g, 0.30 mol) in glacial acetic acid (60 mL) was heated under reflux until a yellow
solution was obtained. 2,5-Dimethoxytetrahydrofuran (39 mL, 40 g, 0.30 mol) was then added
over a period of 30 min and the resulting brown solution was heated for a further 1 h. At
25 °C, the acetic acid was removed under reduced pressure and the black viscous residue was
distilled under reduced pressure to afford a colorless liquid; b.p. 82 - 85 °C/2.1 Torr (ref. [95]
20
b.p. 116 - 117 °C/7.0 Torr); = 1.559;
(68%).
n [ ] 20
D
α = +23.5 (c = 1.0, acetonitrile); yield: 34.9 g
D
(-)-(1S)-2-Bromo-N-(1-phenylethyl)pyrrole (S-17): N-Bromosuccinimide (44 g, 0.25 mol)
was added portionwise to a solution of (+)-(1S)-N-(1-phenylethyl)pyrrole [95] (14; 43 g,
0.25 mol) in tetrahydrofuran (1.2 L) at -75 °C. Once the reagent was completely dissolved,
the pale yellow solution was allowed to reach 25 °C and the solvent was removed. The
residue was dissolved in diethyl ether (40 mL) and washed with a saturated aqueous solution
(40 mL) of hydrogen carbonate. According to gas chromatography (30 m, DB-1, 200 °C), the
ethereal solution contained 3% of 2,6-dibrominated pyrrole (18). Once the solvent was
removed, the pale yellow oil was crystallized from hexanes at -25 °C to afford the product as
20
20
colorless needles which melted after filtration; m.p. -23 to -20 °C; n = 1.5757; d = 1.331;
[ ] 20
α D
= -22.2 (c = 1.2, acetone); yield: 41.8 g (67%).
1 H NMR: δ = 7.3 (m, 2 H), 7.2 (m, 1 H), 7.1 (m, 2 H), 7.03 (dd, J = 3.3, 1.9 Hz, 1 H),
6.18 (t, J = 3.5 Hz, 1 H), 6.15 (dd, J = 3.5, 1.9 Hz, 1 H), 5.56 (q, J = 7.1 Hz, 1 H), 1.80
(d, J = 7.1 Hz, 3 H) ppm.
13 C NMR: δ = 143.5, 128.9, 127.7, 126.4, 119.7, 111.1, 109.5, 101.5, 56.8, 21.7 ppm.
MS: 251 (5%, M + + 1), 249 (5%, M + - 1), 145 (65%), 105 (100%).
D
4