S. Woodward and P. K. Fraser
FULL PAPER
General preparation of ligands 2a d: nBuLi (425 mL, of a 2.5m hexane
solution, 1.09 mmol) was added dropwise to a stirring solution of MTB[9]
(0.30 g, 0.99 mmol) in THF at 08C under an inert atmosphere. Neat alkyl
halide (1.09 mmol) was added, the solution was allowed to warm to room
temperature and monitored by TLC (dichloromethane/light petroleum
1:1). When the reaction was complete (1 h 1 d), the reaction mixture was
quenched with HCl (2m, 5 mL) and extracted with dichloromethane,
washed with brine and dried over MgSO4. Purification by flash column
chromatography (dichloromethane/light petroleum 1:1) yielded low-melt-
ing-point solids or oils whose spectroscopic properties were consistent with
the desired formulation.
J 8.2 plus small unresolved long-range couplings, 1H; H8or8'), 7.22 (ddd,
J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.28 (ddd, J 8.3, 6.8, 1.3, 1H; H6,7,6'or7'), 7.31
(ddd, J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.35 (d, J 8.9, 1H; H3or3'), 7.44 (ddd,
J 8.2, 6.8, 1.2, 1H; H6,7,6'or7'), 7.70(d, J 8.8, 1H; H3or3'), 7.87 (d, J 8.2,
plus small unresolved long-range couplings, 1H; H5or5'), 7.90(d, J 8.2, plus
small unresolved long-range couplings, 1H; H5or5'), 7.94 (d, J 8.9, 1H;
H4or4'), 7.98 (d, J 8.8, 1H; H4or4'); 13C NMR (125.8 MHz, CDCl3) d 22.9
(CHMe2a), 23.3 (CHMe2b), 36.4, 117.3, 117.6, 123.5, 124.6, 125.4, 126.0,
126.3, 126.7, 127.5, 128.3 (2C), 129.2, 129.6, 129.8, 130.3, 132.0, 133.5, 133.7,
137.5, 150.7; IR (KBr disc): nÄmax 3510(w, br, OH), 3429 (w, br, OH), 2960
À
À
À
(w, C H), 2903 (s, C H), 2863 (C H), 1618 (m), 1598 (m), 1205 (m), 1144
(m), 813 (m), 747 cmÀ1 (m); FAB: m/z (%): 344 (20) [M ], 307 (30), 154
(Ra)-(À)-S-Methyl-2-hydroxy-2'-mercapto-1,1'-binaphthyl (1a): Yield
60%; low-melting-point solid; [a]2D4 À26.5 (c 1.02 in CHCl3); 1H NMR
(400.1 MHz, CDCl3) d 2.44 (s, 3H; Me), 4.81 (brs, 1H; OH), 6.97 (d, J
8.3 plus small unresolved long-range couplings, 1H; H8or8'), 7.08 (d, J 8.3
plus small unresolved long-range couplings, 1H; H8or8'), 7.26 (ddd, J 8.3,
6.8, 1.3, 1H; H6,7,6'or7'), 7.30(ddd, J 8.3, 6.8, 1.3, 1H; H6,7,6'or7'), 7.34 (ddd, J
8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.37 (d, J 8.8, 1H; H3or3'), 7.45 (ddd, J 8.1, 6.8,
1.3, 1H; H6,7,6'or7'), 7.60(d, J 8.8, 1H; H3or3'), 7.89 (d, J 8.1, plus small
unresolved long-range couplings, 1H; H5or5'), 7.92 (d, J 8.2, plus small
unresolved long-range couplings, 1H; H5or5'), 7.96 (d, J 8.8, 1H; H4or4'),
8.04 (d, J 8.8, 1H; H4or4'); 13C NMR (67.8 MHz, CDCl3) d 15.6 (Me),
116.7, 117.8, 123.0, 123.9, 124.6, 125.1, 125.8 (3C), 127.1, 127.8, 128.5, 129.5,
130.1, 130.8, 131.7, 133.4, 133.6, 139.1, 151.2; IR (KBr disc): nÄmax 3530(m,
br, OH), 3425 (m, br, OH), 1618 (m), 1595 (m), 1206 (m), 1140 (m),
(100); found (HRMS, FAB) 344.1231 [M ], C23H20OS requires
M
344.1235.
(Ra)-(À)-S-Hexyl-2-hydroxy-2'-mercapto-1,1'-binaphthyl (1 f): Yield 52%;
low-melting-point solid; [a]2D4 À9.9 (c 1.19 in CHCl3); 1H NMR
(500.1 MHz, CDCl3) d 0.88 (t, J 7.1, 3H; (CH2)3Me), 1.25 1.38 (m,
6H; (CH2)3Me), 1.59 (distorted quintet, J ꢁ 6.0, 2H; SCH2CH2), 2.92 (m,
2H; SCH2), 4.83 (brs, 1H; OH), 7.00 (d, J 8.3 plus small unresolved long-
range couplings, 1H; H8or8'), 7.18 (d, J 8.2 plus small unresolved long-
range couplings, 1H; H8or8'), 7.27 (ddd, J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.32
(ddd, J 8.3, 6.8, 1.3, 1H; H6,7,6'or7'), 7.36 (ddd, J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'),
7.39 (d, J 8.9, 1H; H3or3'), 7.48 (ddd, J 8.2, 6.8, 1.2, 1H; H6,7,6'or7'), 7.62 (d,
J 8.8, 1H; H3or3'), 7.91 (d, J 8.2, plus small unresolved long-range
couplings, 1H; H5or5'), 7.94 (d, J 8.2, plus small unresolved long-range
couplings, 1H; H5or5'), 7.97 (d, J 8.9, 1H; H4or4'), 8.00 (d, J 8.8, 1H;
H4or4'); 13C NMR (100.6 MHz, CDCl3) 14.2 (Me), 22.7 (CH2), 28.7 (CH2),
29.3 (CH2), 31.5 (CH2), 32.5 (CH2), 117.1, 117.8, 123.7, 124.6, 124.7, 125.3,
125.9, 126.9, 127.6, 128.4 (2C), 128.5, 129.3, 129.8, 130.5, 131.9, 133.5, 133.7,
812cmÀ1 (s); ES: m/z (%): 317 (100) [M H]; found (HRMS, ES)
317.0997 [M H], C21H17OS requires M 317.1000. This compound has
been reported, but no spectroscopic details have appeared to our know-
ledge.[24]
À
138.1, 151.0; IR (KBr disc): nÄmax 3548 (w, OH), 2945 (w, C H), 2926 (w,
(Ra)-(À)-S-Ethyl-2-hydroxy-2'-mercapto-1,1'-binaphthyl (1b): Yield 62%;
low-melting-point solid; [a]2D4 À19.5 (c 1.06 in CHCl3); 1H NMR
(400.1 MHz, CDCl3) d 1.21 (t, J 7.1, 3 H ; CH2Me), 2.88 (m, 2H;
CH2Me), 4.81 (brs, 1H; OH), 6.95 (d, J 8.2 plus small unresolved long-
range couplings, 1H; H8or8'), 7.13 (d, J 8.2 plus small unresolved long-
range couplings, 1H; H8or8'), 7.21 (ddd, J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.25
(ddd, J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.30(ddd, J 8.0, 6.8, 1.3, 1H; H6,7,6'or7'),
7.34 (d, J 8.8, 1H; H3or3'), 7.41 (ddd, J 8.1, 6.8, 1.3, 1H; H6,7,6'or7'), 7.59 (d,
J 8.8, 1H; H3or3'), 7.85 (d, J 8.1, plus small unresolved long-range
couplings, 1H; H5or5'), 7.86 (d, J 8.2, plus small unresolved long-range
couplings, 1H; H5or5'), 7.91 (d, J 8.8, 1H; H4or4'), 7.94 (d, J 8.8, 1H;
H4or4'); 13C NMR (67.8 MHz, CDCl3) d 14.1 (Me), 26.2 (CH2), 116.8, 117.6,
123.5, 124.2, 124.4, 125.0, 125.6, 126.7, 127.4, 128.2 (3C), 129.1, 129.6, 130.3,
À
À
C H), 2856 (w, C H), 1622 (m), 1582 (m), 1507 (m), 1432 (m), 1338 (m),
1267 (m), 1251 (m), 967 (s), 820(s), 810(s), 746 cm À1 (s); ES: m/z (%): 387
(100) [M ], found (HRMS) 386.1699 [M ], C23H20OS requires
M
386.1704.
(Ra)-(À)-O-Butyl-2-hydroxy-2'-hydroxy-1,1'-binaphthyl (2): Triphenyl-
phosphine (0.734 g, 2.80 mmol) in dry THF (25 mL) and diethyl azodicar-
boxylate (DEAD) (0.44 mL, 2.80 mmol) were added to a stirring solution
of (Ra)-BINOL (0.80 g, 2.80 mmol) and nBuOH (1.28 mL 13.97 mmol).
Yield 70%; low-melting-point solid (when synthesised, we found genuine
(Æ)-2 to be a white solid of m.p. 94 958C); [a]2D4 7.6 (c 1.2 in CHCl3,
1
>98% ee); H NMR (400.1 MHz, CDCl3); 0.76 (t, J 7.3, 3H; Me), 1.14
(sextet, J 7.3, 2H; MeCH2), 1.52 (quintet, J 6.8, 2H; CH2Et), 4.04 (m,
3H; ArOCH2nPr), 5.23 (brs, 1H; OH), 7.19 (d, J 8.3, 1H; H8or8'), 7.27
7.45 (m, 7H, Ar), 7.92-7.96 (m, 2H; H5and5'), 7.97 (d, J 8.8, 1H; H4or4'), 8.02
(d, J 9.0, 1H; H4or4'); 13C NMR (100.6 MHz, CDCl3) d 13.6 (Me), 18.8
(CH2), 31.3 (CH2), 69.5 (CH2), 115.4, 115.7, 116.5, 117.6, 123.2, 124.2, 125.1,
125.2, 126.3, 127.2, 128.1, 128.2, 129.2, 129.6, 129.7, 130.8, 134.0, 134.2, 151.4,
155.6; IR (diffuse reflectance): nÄmax 3472 (m, OH), 3417 (w, OH), 2969 (w,
À
131.6, 133.2, 133.5, 137.6, 150.8; IR (KBr disc): nÄmax 3501 (w, C H), 3500
À
À
(s, br, OH), 3417 (m, br, OH), 2961 (w, C H), 2924 (w, C H), 2862 (w,
À
C H), 1618 (s), 1595 (s), 1501 (s), 1203 (s), 1143 (s), 969 (m), 814 (s),
747 cmÀ1 (m); ES m/z (%): 331 (100) [M H]; found (HRMS, FAB)
330.1065 [M ]; C22H18OS requires M 330.1078. This compound has been
reported, but no spectroscopic details have appeared to our knowledge.[24]
À
À
C H), 2957 (w, C H), 1619 (m), 1590(m), 1505 (m), 1379 (m), 1272 (m),
1205 (m), 1179 (m), 1081 (m, C-O), 814 cmÀ1 (s). Racemic 2 has appeared,
but apparently no spectroscopic details have been published.[25]
(Ra)-(À)-S-Propyl-2-hydroxy-2'-mercapto-1,1'-binaphthyl (1c): Yield
72%; colourless oil; [a]2D4 À8.6 (c 3.42 in CHCl3); 1H NMR
(400.1 MHz, CDCl3) d 0.90 (t, J 7.4, 3H; Me), 1.59 (sextet, J 7.4,
2H; central CH2), 2.86 (m, 2H; SCH2), 4.78 (brs, 1H; OH), 6.96 (d, J 8.2
plus small unresolved long-range couplings, 1H; H8or8'), 7.13 (d, J 8.2 plus
small unresolved long-range couplings, 1H; H8or8'), 7.22 (ddd, J 8.2, 6.8,
1.3, 1H; H6,7,6'or7'), 7.28 (ddd, J 8.2, 6.8, 1.3, 1H; H6,7,6'or7'), 7.32 (ddd, J 8.0,
6.8, 1.3, 1H; H6,7,6'or7'), 7.35 (d, J 8.8, 1H; H3or3'), 7.43 (ddd, J 8.1, 6.8, 1.3,
1H; H6,7,6'or7'), 7.64 (d, J 8.8, 1H; H3or3'), 7.87 (d, J 8.1, plus small
unresolved long-range couplings, 1H; H5or5'), 7.89 (d, J 8.2, plus small
unresolved long-range couplings, 1H; H5or5'), 7.93 (d, J 8.8, H4or4'), 7.98
(1H; d, J 8.8, 1H; H4or4'); 13C NMR (67.8 MHz, CDCl3) d 13.4 (Me),
22.5 (CH2), 34.2 (CH2), 117.6, 123.4, 124.4 (2C), 125.0, 125.7, 126.7, 127.4,
128.1, 128.2 (3C), 128.4, 129.1, 129.6, 130.3, 131.7, 133.3, 137.8, 150.8; IR
Enone preparation by LDA-enolate chemistry: Diisopropylamine
(3.34 mL, 23.8 mmol) in THF (30mL) was cooled to À788C, and nBuLi
(12.0mL, 2.0 m, 23.8 mmol) was added. The solution was stirred for 30min
before addition of ketone (23.8 mmol) in THF (0.7 mL). After 30 min, neat
aldehyde (23.8 mmol) was added dropwise. The solution was stirred for a
further 30min at À788C before the cooling bath was removed, and stirring
was continued at ambient temperature for 10mins. Water (20mL) was
added, and the layers were separated, the organic phase was dried
(MgSO4), and the solvent was removed. The residue was dissolved in
diethyl ether, conc. HCl (ca 5 mL) was added, and the elimination of the
alcohol was monitored by TLC. Flash column chromatography (diethyl
ether/pentane 1:8) or Kugelrohr distillation followed. Typically 55 70%
isolated yield was obtained.
À
À
(CHCl3 solution): nÄmax 3537 (s, OH), 2966 (s, C H), 2933 (m, C H), 2874
À
(w, C H), 1621 (s), 1596 (s), 1466 (m), 1381 (s), 1355 (s), 1145 (s), 1120(m),
À1
970(m), 862 cm (w); ES: m/z (%): 345 (100) [M H]; found (HRMS,
Enone preparation by Wittig chemistry: The aldehyde (20.7 mmol) and
Ph3P CH(COMe) (21.7 mmol) were heated to reflux in THF (40mL) for
FAB) 344.1231 [M ], C23H20OS requires M 344.1235.
(Ra)-(À)-S-(1-methyl)ethyl-2-hydroxy-2'-mercapto-1,1'-binaphthyl (1d):
Yield 35%; low-melting-point solid; [a]2D4 À4.1 (c 1.06 in CHCl3);
1H NMR (400 MHz, CDCl3) d 1.19 (d, J 6.7, 3H; CHMe2a), 1.25 (d, J
6.7, 3H; CHMe2b), 3.53 (septet, J 6.7, 1H; SCH), 4.76 (brs, 1H; OH), 6.95
(d, J 8.2 plus small unresolved long-range couplings, 1H; H8or8'), 7.13 (d,
6 h overnight, the solution was cooled, and the solvent was removed. The
enone was extracted from the white precipitate with pentane (5 Â 10mL),
and the pentane was removed under reduced pressure. The resulting oil was
purified by column chromatography (hexane/Et2O 23:2). Typically 55
75% isolated yield was obtained.
780
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Chem. Eur. J. 2003, 9, No. 3