T. Noe€l et al. / Tetrahedron 63 (2007) 12961–12967
12965
4.5. A typical procedure for the preparation
of (S,S)-nbd*-ligands
CDCl3): d 0.95–1.04 (m, 2H), 1.05–1.20 (m, 4H), 1.22–1.32
(m, 4H), 1.62–1.79 (m, 10H), 1.84 (t, J¼1.6 Hz, 2H), 2.08
(m, 2H), 3.26 (dt, J¼3.9, 1.6 Hz, 2H), 6.02 (td, J¼1.6,
3.9 Hz, 2H). 13C NMR (125.7 MHz, CDCl3): d 26.2 (CH2),
26.5 (CH2), 31.1 (CH2), 31.2 (CH2), 39.8 (CH), 51.7 (CH),
71.1 (CH2), 130.7 (CH), 164.1 (C). IR (KBr, thin film):
3059, 2960, 2923, 2850, 1448, 1276, 1184, 890, 806,
788 cmꢁ1. APCI-MS: 257 [M+H]+. EIMS m/z (rel intensity
%): 256 (M+, 43), 189 (15), 173 (33), 148 (51), 131 (21),
117 (24), 105 (34), 91 (58), 79 (38), 55 (69), 41 (100). [a]D25
ꢁ58 (c 0.96, CHCl3). HRMS (EI) calcd for C19H28
256.2191, found 256.2190.
4.5.1. Synthesis of (S,S)-Bn-nbd* (4a). A solution of bis-
triflate (S,S)-3 (104.7 mg, 269.7 mmol) and PdCl2(dppf)$
CH2Cl2 (4.7 mg, 5.79 mmol) in Et2O (1.0 mL) was cooled
in an ice bath. To the resulting red suspension was added
BnMgCl (1.35 mL, 1.77 mmol, 20 w/w % in THF) under ar-
gon. The reaction mixture was stirred for 1 h at room temper-
ature, quenched with brine (25 mL) and extracted with
EtOAc (4ꢂ50 mL). The combined organic phases were
dried over MgSO4 and concentrated in vacuo. The crude
product was purified by flash chromatography over silica
gel (isooctane/CHCl3, 96/4) resulting in a white solid, which
contained a significant amount of diphenylethane, which
was removed under reduced pressure (<1 mmHg, 1 night)
resulting in pure (S,S)-Bn-nbd* (4a) as a white solid,
4.5.4. Synthesis of (S,S)-allyl-nbd* (4d). The reaction was
performed on bis-triflate (S,S)-3 (508.5 mg, 1.31 mmol)
according to the typical procedure, using an allylMgBr solu-
tion (8.85 mL, 8.99 mmol, 1 M in Et2O). After 30 min the
reaction was quenched with H2O and extracted with pentane.
The combined organic phases were dried over MgSO4 and
carefully concentrated in vacuo. Purification by flash chro-
matography over silica gel (pentane) resulted in pure (S,S)-
allyl-nbd* (4d) as a colourless oil, 92.5 mg (41%). 1H
NMR (500 MHz, CDCl3): d 1.97 (t, J¼1.6 Hz, 2H), 2.93
(m, 4H), 3.22 (dt, J¼4.0, 1.6 Hz, 2H), 5.01 (ddt, J¼10.0,
1.2, 1.2 Hz, 2H), 5.04 (ddd, J¼17.0, 1.6, 3.4 Hz, 2H), 5.79
(tdd, J¼3.5, 10.0, 17.0 Hz, 2H), 6.18 (td, J¼1.7, 4.0 Hz,
2H). 13C NMR (125.7 MHz, CDCl3): d 36.0 (CH2), 53.3
(CH), 71.8 (CH2), 115.7 (CH2), 133.5 (CH), 135.7 (CH),
157.0 (C). IR (KBr, thin film): 3076, 2972, 2932, 2866,
1
53.0 mg (72%). H NMR (500 MHz, CDCl3): d 1.94 (t,
J¼1.7 Hz, 2H), 3.14 (dt, J¼3.8, 1.7 Hz, 2H), 3.49 (s, 4H),
6.02 (dt, J¼3.8, 1.6 Hz, 2H), 7.09 (d, J¼7.2 Hz, 4H), 7.18
(tt, J¼7.2, 1.2 Hz, 2H), 7.26 (t, J¼7.2 Hz, 4H). 13C NMR
(125.7 MHz, CDCl3): d 38.0 (CH2), 53.1 (CH), 71.4
(CH2), 125.9 (CH), 128.1 (CH), 129.0 (CH), 134.3 (CH),
139.1 (C), 156.9 (C). IR (KBr, thin film): 2970, 2950,
2929, 2878, 1600, 1492, 1451, 1306, 1183, 1069, 1026,
948, 856, 780, 752, 737, 708 cmꢁ1. APCI-MS: 273
[M+H]+. EIMS m/z (rel intensity %): 272 (M+, 9), 181
(34), 165 (21), 156 (34), 141 (17), 128 (22), 115 (39), 103
(8), 91 (88), 84 (29), 65 (30), 49 (71), 40 (100). [a]D25
ꢁ180 (c 1.07, CHCl3). Mp 67 ꢀC. HRMS (EI) calcd for
C21H20 272.1565, found 272.1569.
1640, 1607, 1427, 1301, 1263, 1185, 993, 912, 786 cmꢁ1
.
APCI-MS: 173 [M+H]+. EIMS m/z (rel intensity %): 172
(M+, 5), 131 (45), 115 (28), 106 (18), 91 (100), 78 (62), 65
(18), 51 (18), 41 (18). [a]2D5 ꢁ151.1 (c 1.06, CHCl3).
HRMS (EI) calcd for C13H16 172.1252, found 172.1259.
4.5.2. Synthesis of (S,S)-i-Bu-nbd* (4b). The reaction was
performed on bis-triflate (S,S)-3 (501.3 mg, 1.29 mmol)
according to the typical procedure, using a i-BuMgCl
(4.5 mL, 8.99 mmol, 2 M in Et2O) solution. After 1 h the
reaction was quenched with H2O and extracted with pentane.
The combined organic phases were dried on MgSO4 and
carefully concentrated invacuo. Purification by flash chroma-
tography over silica gel (pentane) resulted in pure (S,S)-i-Bu-
4.6. Synthesis of [RhCl((S,S)-allyl-nbd*)]2
(S,S)-Allyl-nbd*
(4d)
(16.9 mg,
98.1 mmol)
and
[RhCl(C2H4)2]2 (17.9 mg, 92.0 mmol Rh) were dissolved in
CHCl3 (5 mL) and stirred for 3 h under argon. Purification
by flash chromatography over silica gel (hexane/CH2Cl2,
60/40) resulted in pure [RhCl((S,S)-allyl-nbd*)]2 as a yellow-
ish oil, 25.9 mg (78%). 1H NMR (300 MHz, CDCl3): d 1.18
(s, 4H), 2.45 (dd, J¼6.9, 14.6 Hz, 4H), 2.94 (dd, J¼7.0,
14.6 Hz, 4H), 3.57 (m, 4H), 3.60 (m, 4H), 5.17 (dd, J¼1.0,
10.0 Hz, 4H), 5.27 (dd, J¼1.2, 17.0 Hz, 4H), 6.37 (tdd, J¼
3.2, 10.0, 17.0 Hz, 4H). 13C NMR (125.7 MHz, CDCl3):
1
nbd* (4b) as a colourless oil, 86.7 mg (33%). H NMR
(500 MHz, CDCl3): d 0.81 (d, J¼6.6 Hz, 6H), 0.87 (d,
J¼6.6 Hz, 6H), 1.71–1.80 (septet, J¼6.6 Hz, 2H), 1.94 (t, J¼
1.6 Hz, 2H), 2.03–2.08 (dq, J¼1.5, 6.8 Hz, 4H), 3.17 (dt,
J¼3.9, 1.6 Hz, 2H), 6.12 (td, J¼1.5, 3.9 Hz, 2H). 13C NMR
(125.7 MHz, CDCl3): d 22.6 (CH3), 22.8 (CH3), 26.6 (CH),
41.0 (CH2), 53.4 (CH), 71.9 (CH2), 133.5 (CH), 157.9 (C).
IR (KBr, thin film): 3062, 2955, 2930, 2900, 2867, 2830,
1464, 1383, 1366, 1298, 1185, 1167, 780 cmꢁ1. APCI-MS:
205 [M+H]+. EIMS m/z (rel intensity %): 204 (M+, 49), 161
(27), 147 (25), 122 (48), 117 (20), 105 (60), 91 (51), 80
(100), 66 (44), 43 (77). [a]2D5 ꢁ103 (c 1.14, CHCl3). HRMS
(EI) calcd for C15H24 204.1878, found 204.1873.
d 38.5 (CH2), 47.4 (d, JC–Rh¼10.6 Hz, CH), 53.1 (d, JC–Rh
¼
3.0 Hz, CH), 59.5 (d, JC–Rh¼7.5 Hz, CH2), 69.4 (d, JC–Rh
¼
11.3 Hz, C), 116.6 (CH2), 135.4 (CH). IR (KBr, thin film):
3071, 2988, 2911, 1634, 1422, 1307, 1234, 1170, 991,
913 cmꢁ1. ES-MS: 584.9 ([RhOH((S,S)-allyl-nbd*)]2+H+),
275 (Rh+((S,S)-allyl-nbd*)). EIMS m/z (rel intensity %):
620 (M+, 44), 584 (9), 548 (26), 412 (100), 372 (41), 346
(12), 308 (9), 273 (56), 218 (41), 205 (33), 168 (15), 115 (20),
103 (24), 77 (20), 49(22). [a]2D5 +3.4 (c 0.90, CHCl3). HRMS
(EI) calcd for C26H32Cl2Rh2 619.9991, found 620.0003.
4.5.3. Synthesis of (S,S)-c-Hex-nbd* (4c). The reaction was
performed on bis-triflate (S,S)-3 (101.0 mg, 257.6 mmol)
according to the typical procedure, using a c-HexMgCl
(0.9 mL, 177 mmol, 2 M in Et2O) solution. After 1 h the reac-
tion was quenched with H2O and extracted with pentane. The
combined organic phase were dried on MgSO4 and concen-
trated invacuo. Purification by flash chromatography over sil-
ica gel (pentane) resulted in pure (S,S)-c-Hex-nbd* (4c) as
a colourless oil, 51.0 mg (77%). 1H NMR (500 MHz,
4.7. Typical procedure for the asymmetric 1,4-addition
of phenylboronic acid (6) to cyclic enones 5a and 5b
Chiral ligand (S,S)-nbd* (4) (2.7 mg, 9.9 mmol) and [RhCl-
(C2H4)2]2 (1.8 mg, 9.0 mmol) were dissolved in dioxane