Syntheses of C2-symmetric vicinal diamines derived from tartaric acid

Article abstract of DOI:10.1016/S0957-4166(99)00353-5

C₂-symmetric vicinal diamines 3b-f, derived from L-tartaric acid, with increasingly bulky terminal ether functionalities were prepared using two distinct sequences. Diamines 3b,c were obtained from the corresponding vicinal diols 4b,c, while di

Full text of DOI:10.1016/S0957-4166(99)00353-5

Pergamon
Tetrahedron: Asymmetry 10 (1999) 3559–3570
Syntheses of C2-symmetric vicinal diamines derived from
tartaric acid
Andreas Scheurer,a,b Paul Mosset a,∗ and Rolf W. Saalfrank b,∗
aLaboratoire de Synthèses et Activations de Biomolécules, CNRS ESA 6052, Ecole Nationale Supérieure de Chimie de Rennes,
Avenue du Général Leclerc, F-35700 Rennes, France
bInstitut für Organische Chemie der Universität Erlangen-Nürnberg, Henkestraβe 42, D-91054 Erlangen, Germany
Received 29 July 1999; accepted 11 August 1999
Abstract
C2-symmetric vicinal diamines 3b–f, derived from L-tartaric acid, with increasingly bulky terminal ether
functionalities were prepared using two distinct sequences. Diamines 3b,c were obtained from the corresponding
vicinal diols 4b,c, while diamines 3d–f were generated from dihydroxydiazide 7 via deprotection–reprotection
strategies. © 1999 Elsevier Science Ltd. All rights reserved.
1. Introduction
During the past decade, remarkable progress has been made in the field of metal-catalyzed asymmetric
syntheses.1,2 The design of numerous effective enantiomerically pure catalysts is based on C2-symmetric
diamines,3 such as 1,2-diphenylethylenediamine and 1,2-diaminocyclohexane. Recently, we reported on
the efficient synthesis of non-cyclic vicinal diamine (2S,3S)-2,3-diaminobutane-1,4-diol 2 and (2S,3S)-
1,4-bis(benzyloxy)-2,3-diaminobutane 3a, starting from diethyl L-tartrate (+)-14 (Scheme 1).
In order to test the influence of different (2S,3S)-2,3-diaminobutane-1,4-diether ligands on the catalytic
effect of the corresponding chelate complexes, we synthesized the diamines 3b5 and 3c–f, respectively.
Hitherto, the diamines 3c–f with bulky substituents such as 2-naphthylmethoxy, triphenylmethoxy, (t-
butyldimethylsilyl)oxy and (t-butyldiphenylsilyl)oxy were unknown (Scheme 2).
2. Results and discussion
The diols6 4a–c were converted to the vicinal diamines 3a–c by a three step sequence. Standard
mesylation of 4a–c afforded dimesylates 5a–c which were converted to diazides 6a–c with sodium
∗
Corresponding authors. E-mail: mosset@ensc-rennes.fr
0957-4166/99/$ - see front matter © 1999 Elsevier Science Ltd. All rights reserved.
PII: S0957-4166(99)00353-5

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Scheme 1.
Scheme 2.
azide in DMSO.7 Catalytic hydrogenation of the azide functions of 6a–c using palladium on charcoal
afforded the diamines 3a–c8 without touching the protecting groups. While the reduction of 6a,b could
be performed in methanol, diazide 6c was reduced in THF9 (Scheme 3).
Scheme 3. (a) MsCl, Et3N, CH2Cl2, 0°C, 1 h, 99% for 4a and 4b, quant. for 4c. (b) NaN3, DMSO, 80°C, 24 h, 88% for 5a, 95%
for 5b, 85% for 5c. (c) H2, Pd/C, MeOH or THF for 3a, MeOH for 3b, THF for 3c, ca. 20°C, 18 h, quant.
(2S,3S)-1,4-Bis(triphenylmethoxy)-2,3-diaminobutane 3d was synthesized from diazide 6a, which was
first deprotected with boron trichloride dimethyl sulfide complex to give diol 7.4 Reprotection of the
hydroxyl groups of 7 using 1-tritylpyridinium tetrafluoroborate in acetonitrile10,11 yielded diazide 6d.
Hydrogenation of diazide 6d with Pearlman’s catalyst in THF12 afforded diamine 3d in excellent yield
(Scheme 4).
Scheme 4. (a) BCl3·Me2S, CH2Cl2, ca. 20°C, 2–3 h, 81%. (b) TrBF4·Py, CH3CN, 65°C, 8 h, 82%. (c) H2, Pd(OH)2/C, THF,
ca. 20°C, 18 h, quant.

A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
3561
The diamines 3e,f were prepared starting from diol 7, which was first protected by silylation in
DMF with t-butyldimethylchlorosilane13 or t-butyldiphenylchlorosilane14 , respectively, to give 6e,f in
good yield. Subsequent catalytic hydrogenation of 6e,f with palladium on carbon in THF generated the
corresponding diamines 3e,f (Scheme 5).
Scheme 5. (a) t-BuMe2SiCl, imidazole, DMF, 0°C, 24 h, 98%. (b) t-BuPh2SiCl, imidazole, DMF, 0°C, 24 h, 94%. (c) H2, Pd/C,
THF, ca. 20°C, 18 h, quant.
3. Conclusion
In summary, a series of C2-symmetric vicinal diamines derived from L-tartaric acid were generated.
The increasing bulkiness of the terminal ether functionalities of the diamines 3b–f make them useful
precursors for the preparation of chiral ligands and metal chelates for asymmetric catalysis.15
4. Experimental
4.1. (2S,3S)-1,4-Bis(methoxy)butane-2,3-diol dimethanesulfonate 5b
Methanesulfonyl chloride (0.218 mL, 2.8 mmol) was slowly added at 0°C to a solution of diol 4b
(0.175 g, 1.17 mmol) and triethylamine (0.49 mL, 3.5 mmol) in anhydrous dichloromethane (6 mL).
After stirring for 1 h at 0°C, the reaction mixture was allowed to warm up to ca. 20°C. Water was added
and the resulting mixture was extracted three times with ethyl acetate. The combined organic phases
were successively washed with brine and water, dried (MgSO4) and concentrated. Chromatography
on silica gel (ethyl acetate:petroleum ether 2:3) afforded dimesylate 5b as a pale yellow oil, which
crystallized after storage in the refrigerator yielding cream-colored crystals (0.355 g, 99%, Rf=0.10,
ethyl acetate:petroleum ether 2:3, mp 42–44°C); IR (neat, NaCl): ν 3031, 2941, 2824, 1460, 1359, 1176,
1
1126, 1027, 975, 920, 828, 801, 759 cm−1; H NMR (400 MHz, CDCl3) δ 4.96–4.91 (m, 2H, CH-
OMs),16 3.76–3.64 (m, 4H, CHCH2O),16 3.41 (s, 6H, OCH3), 3.13 (s, 6H, OMs); 13C NMR (100 MHz,
CDCl3): δ 78.72 (dm, 2C, J=149.9 Hz, CH-OMs), 71.19 (tqd, 2C, J=143.8, 5.4, 1.8 Hz, CH2O), 59.25
(qt, 2C, J=141.9, 3.0 Hz, OCH3), 38.72 (q, 2C, J=139.6 Hz, OMs); MS (EI, 70 eV) m/z (%): 307 (0.05)
[M+H]+, 275 (0.2) [M−OMe]+, 165 (74) [M−MsOH−CH2OCH3]+, 87 (80), 79 (29), 59 (69), 45 (100,
23
23
23
e.g. base peak); [α]23 −22.4, [α]
−23.3, [α]
−26.4, [α]
−43.5 (c=3.8, CHCl3).
D
578
546
436

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4.2. (2S,3S)-1,4-Bis(methoxy)-2,3-diazidobutane 6b
A mixture of dimesylate 5b (0.355 g, 1.17 mmol) and sodium azide (0.266 g, 4.1 mmol) in DMSO
(3.5 mL) was stirred at 80°C for 1 day, cooled to ca. 20°C, and the white suspension was diluted with
ca. 15% aq. NaCl (10 mL). The aqueous layer was extracted three times with light petroleum ether and
the combined organic extracts were dried (MgSO4). Concentration in vacuo and chromatography of the
remaining brown liquid on silica gel (ether:light petroleum ether 5:95) afforded diazide 6b as a colorless
liquid (0.206 g, 88%, Rf=0.24, ethyl acetate:petroleum ether 1:9); IR (neat, NaCl): ν 2992, 2931, 2897,
2835, 2818, 2106, 1458, 1335, 1267, 1197, 1125 cm−1; 1H NMR (400 MHz, CDCl3): δ 3.71–3.65 (m, 2H,
CH-N3),16 3.62–3.58 (m, 4H, CHCH2O),16 3.41 (s, 6H, OCH3); 13C NMR (100 MHz, CDCl3): δ 72.04
(tm, 2C, J=143.1 Hz, CH2O), 60.89 (d sextet, 2C, J=143.7, 2.6 Hz, CH-N3), 59.23 (qt, 2C, J=141.6, 2.9
Hz, OCH3); MS (EI, 70 eV) m/z (%): 100 (7) [M/2]+, 72 (23) [M/2−N2]+, 45 (100) [MeOCH2]+, 41 (56),
24
24
24
24
29 (100); [α]24 −45.8, [α]
−47.8, [α]
−53.7, [α]
−86.2, [α]
−119.4 (c=3.4, CHCl3).
D
578
546
436
365
4.3. (2S,3S)-1,4-Bis(methoxy)-2,3-diaminobutane 3b
A solution of diazide 6b (0.170 g, 0.85 mmol) in methanol (10 mL) in a one-necked flask (250 mL)
was stirred during 5 min under a slow stream of nitrogen. Then 10% Pd/C (0.060 g) was suspended
into the solution and the flask was rapidly flashed with a strong stream of hydrogen and the mixture
was hydrogenated at ca. 20°C and at atmospheric pressure for 18 h. The catalyst was then removed by
filtration over Celite and the filtrate was evaporated under vacuum to afford diamine 3b as a colorless
syrup (0.126 g, quant.); IR (neat, NaCl): ν 3369 (broad), 3284, 2982, 2926, 2896, 2822, 1602, 1461, 1194,
1
1113, 954, 753 cm−1; H NMR (400 MHz, CDCl3): δ 3.41 (pseudo dd, 2H, J=9.3, 4.3 Hz, CH2O),16
3.36 (s, 6H, OCH3), 3.33 (pseudo dd, 2H, J=9.3, 6.5 Hz, CH2O),16 2.97–2.90 (m, 2H, CH-NH2),16 1.54
(broad s, 4H, CH-NH2); 13C NMR (100 MHz, CDCl3): δ 74.61 (tm, 2C, J=142 Hz, CH2O), 59.08 (qt,
2C, J=141.1, 2.7 Hz, OCH3), 52.18 (dm, 2C, J=137 Hz, CH-NH2); MS (EI, 70 eV) m/z (%): 103 (8)
[M−CH2OCH3]+, 86 (7) [M−NH3−CH2OCH3]+, 74 (100) [M/2]+, 43 (33) [M/2−OMe]+, 30 (16); [α]24
D
24
24
24
24
+5.6, [α]
+5.8, [α]
+6.4, [α]
+11.1, [α]
+17.0 (c=2.0, CHCl3).
578
546
436
365
For analytical purposes, diamine 3b was converted into its dibenzamide as follows:
Benzoyl chloride (0.14 mL, 1.2 mmol) was slowly added at 0°C to a solution of diamine 3b (0.06 g,
0.4 mmol) and triethylamine (0.224 mL, 1.6 mmol) in anhydrous dichloromethane (4 mL). After stirring
for 1 h at 0°C, the reaction mixture was allowed to warm up to ca. 20°C and stirred for additional 18
h. Water was added and the resulting mixture was extracted three times with ethyl acetate. Combined
organic phases were successively washed with brine and water, dried (MgSO4) and concentrated. Short
plug chromatography on silica gel (methanol:dichloromethane 1:99) afforded dibenzamide of 3b as a
cream-colored solid [0.124 g, 87%, Rf=0.22, methanol:dichloromethane 2:98, mp 148–149°C (ethyl
acetate:petroleum ether)]; IR (Nujol, NaCl): ν 3301 (broad), 1634, 1531, 1192, 1106, 955, 802, 696
cm−1; 1H NMR (400 MHz, CDCl3) δ 7.75 (dm, 4H, J=8.3 Hz, H ortho), 7.44 (ddt, 2H, J=8.3, 6.3, 1.4
Hz, H para), 7.40–7.34 (m, 4H, H meta), 7.25 (broad d, 2H, J=7.8 Hz, NH), 4.65–4.56 (m, 2H, CH-NH),
3.71 (pseudo dd, 2H, J=10.0, 2.9 Hz, CH2O), 3.63 (pseudo dd, 2H, J=10.0, 3.6 Hz, CH2O), 3.40 (s, 6H,
OCH3); 13C NMR (100 MHz, CDCl3): δ 168.01 (2C, CONH), 134.08 (2Cipso), 131.50 (dddd, 2Cpara
J=161.0, 7.9, 7.2, 1.1 Hz), 128.50 (d pseudo dd, 4Cmeta, J=161.3, 7.7, 1.0 Hz), 127.04 (dm, 4Cortho
,
,
J=160.4 Hz), 71.61 (tq, 2C, J=142.6, 4.9 Hz, OCH2-CH), 59.30 (qt, 2C, J=141.2, 2.7 Hz, OCH3),
51.08 (dm, 2C, J=140.6 Hz, CH-NH); MS (EI, 70 eV) m/z (%): 311 (17) [M−CH2OCH3]+, 279 (21)
[M−MeOH−CH2OCH3]+, 203 (12) [M−MeOH−PhCONH2]+, 190 (22) [M−CH2OCH3−PhCONH2]+,
24
178 (53) [M/2]+, 147 (48) [M/2−OCH3]+, 105 (86) [PhCO]+, 85 (100); [α]24 −49.1, [α]
−51.4,
D
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A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
3563
24
[α]
−59.0 (c=2.2, CHCl3). Anal. calcd for C20H24N2O4: C, 67.40; H, 6.79; N, 7.86. Found: C, 67.55;
546
H, 6.98; N, 7.65.
4.4. (2S,3S)-1,4-Bis(2-naphthylmethoxy)butane-2,3-diol 4c
In a round-bottomed three-neck flask, equipped with a stirring bar, pressure equalizing drop funnel, a
reflux condenser and a stopper, was placed under nitrogen sodium hydride [(0.74 g of a 60% dispersion
in oil, 0.44 g, 18.5 mmol); the oil was removed by washing with petroleum ether (3×2.5 mL)] and dry
THF (10 mL) was then added under nitrogen. A solution of (+)-2,3-O-isopropylidene-L-threitol (1.27 g,
7.8 mmol) in dry THF (5 mL) was then added dropwise with stirring at 0°C, followed by washing of the
addition funnel with dry THF (3 mL). Powdered 2-(bromomethyl)naphthalene (3.6 g, 16.3 mmol) was
added in one portion. After stirring for 14 h at ca. 20°C, the mixture was heated at reflux for 2 h, cooled
in an ice bath and quenched by addition of water until a clear yellow solution resulted. THF was removed
under reduced pressure, the residue diluted with water and extracted three times with ethyl acetate. The
organic extracts were combined, dried (MgSO4) and, after evaporation of volatile material, the crude
1
ketal (2S,3S)-2,3-O-isopropylidene-1,4-bis(2-naphthylmethoxy)butane 817 was obtained as an oil; H
NMR (400 MHz, CDCl3): δ 7.85–7.73 (m, 6H of 2-naphthyl, H4,5,8), 7.73 (broad s, 2H of 2-naphthyl,
H1), 7.47–7.42 (m, 4H arom., H6,7, ∆δ=0 ppm, J56=J78=8.2 Hz, J67=6.9 Hz, J57=J68=1.2 Hz, J58=0.7
Hz), 7.40 (dd, J=8.3, 1.8 Hz, 2H of 2-naphthyl, H3), 4.71 (d, 2H, J=12.4 Hz, CH2-2-naphthyl), 4.69
(d, 2H, J=12.4 Hz, CH2-2-naphthyl), 4.11–4.04 (m, 2H, OCH2CH),16 3.68–3.59 (m, 4H, OCH2-CH),16
1.45 (s, 6H, C(CH3)2); 13C NMR (100 MHz, CDCl3): δ 135.40 (2Cipso), 133.18 (2Cipso), 132.95 (2Cipso),
128.16 (2CH), 127.83 (2CH), 127.67 (2CH), 126.41 (2CH), 126.08 (2CH), 125.85 (2CH), 125.60 (2CH),
109.73 (1C, C(CH3)2), 77.48 (2C, OCH2CH), 73.58 (2C, CH2-2-naphthyl), 70.65 (2C, OCH2CH), 27.03
(2C, C(CH3)2).
The crude ketal 8 was dissolved in methanol (10 mL), 1.0 N hydrochloric acid (1 mL) and the
resulting mixture was heated at reflux. Acetone and methanol were slowly distilled off with a Vigreux
column. After 1 h, more methanol (10 mL) was added and the distillation was continued for about 5
h. After cooling to ca. 20°C, a solid material was obtained, which was dissolved in saturated aqueous
sodium carbonate solution (25 mL) and extracted four times with ethyl acetate. The combined organic
extracts were dried (MgSO4) and after evaporation of the solvent the crude reaction product was obtained
as a slight yellow oil, which solidified in the refrigerator. This solid was recrystallized in petroleum
ether:toluene to provide 2.44 g (78% for two steps) of diol 4c as pale yellow crystals (Rf=0.22, ethyl
acetate:petroleum ether 2:3, mp 115–116°C, NMR-analysis of mother liquor showed the presence of 2-
(bromomethyl)naphthalene with less than 5% diol); IR (Nujol, NaCl): ν 3395 (broad), 3051, 1600, 1100,
1
1060, 1041, 1006, 952, 902, 863, 825, 755, 732 cm−1; H NMR (400 MHz, CDCl3): δ 7.84–7.78 (m,
6H of 2-naphthyl), 7.74 (broad d, J=0.7 Hz, 2H of 2-naphthyl), 7.50–7.44 (m, 4H of 2-naphthyl, H6,7
,
∆δ=0.0057 ppm, J56=J78=8.2 Hz, J67=6.9 Hz, J57=J68=1.2 Hz, J58=0.7 Hz), 7.42 (dd, J=8.5, 1.6 Hz, 2H
of 2-naphthyl), 4.71 (d, 2H, J=12.1 Hz, CH2-2-naphthyl), 4.68 (d, 2H, J=12.1 Hz, CH2-2-naphthyl), 3.91
(dm, 2H, J=4.1 Hz, CH-OH),16 3.66 (pseudo dd, 2H, J=9.7, 4.4 Hz, OCH2-CH),16 3.62 (pseudo dd, 2H,
J=9.7, 5.6 Hz, OCH2-CH),16 2.83 (d, 2H, J=4.1 Hz, CH-OH); 13C NMR (100 MHz, CDCl3): δ 135.14
1
3
(C2 arom.), 133.19 and 133.01 (C4a and C8a arom.), 128.30 (dd, JCH=159.2 Hz, JC4-H5=5.0 Hz, C4
1
1
arom.), 127.87 (dm, JCH=158.1 Hz, C8 arom.), 127.70 (dm, JCH=158.8 Hz, C5 arom.), 126.64 (ddtd,
1JCH=157.8 Hz, 3JC3-H1 ∼9 Hz, 3Jwith CH2O ∼5.5 Hz, 2JC3-H4 ∼1 Hz, C3 arom.), 126.18 (dd, 1JCH=159.5
Hz, 3JC6-H8 or 3JC7-H5=8.4 Hz, C6 or C7 arom.), 125.99 (dd, 1JCH=159.5 Hz, 3JC6-H8 or 3JC7-H5=8.2 Hz,
1
3
3
C6 or C7 arom.), 125.66 (ddt, JCH=158.4 Hz, JC1-H3=7.2 Hz, Jwith CH2O=4.0 Hz, C1 arom.), 73.67
(tm, 1JCH=142.0 Hz, OCH2CHOH), 71.95 (pseudo tt, JCH=141.5 Hz, 3Jwith OCH2=3.9 Hz, 2-naphthyl-
1
CH2O), 70.61 (dm, 1JCH=143.1 Hz, CHOH); MS (EI, 70 eV) m/z (%): 402 (2) [M]+, 262 (16), 157 (47)

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26
[OCH2-2-naphthyl]+, 141 (100) [CH2-2-naphthyl]+, 129 (29), 115 (32); [α]26 −6.4, [α]52768 −6.7, [α]
D
546
26
−7.6, [α]
−13.2 (c=3.0, CHCl3). Anal. calcd for C26H26O4: C, 77.58; H, 6.52. Found: C, 77.64; H,
436
6.51.
4.5. (2S,3S)-1,4-Bis(2-naphthylmethoxy)butane-2,3-diol dimethanesulfonate 5c
Methanesulfonyl chloride (0.093 mL, 1.2 mmol) was slowly added at 0°C to a solution of diol 4c
(0.201 g, 0.5 mmol) and triethylamine (0.209 mL, 1.5 mmol) in anhydrous dichloromethane (2.5 mL).
After stirring for 1 h at 0°C, the reaction mixture was allowed to warm up to ca. 20°C. Water was added
and the resulting mixture was extracted three times with ethyl acetate. The combined organic phases were
successively washed with brine and water, dried (MgSO4) and concentrated. Chromatography on silica
gel (ethyl acetate:petroleum ether 1:4) afforded dimesylate 5c as a white solid (0.28 g, quant., Rf=0.36,
ethyl acetate:petroleum ether 2:3, mp 100–102°C); IR (Nujol, NaCl): ν 3022, 1345, 1178, 1123, 1028,
1
974, 907, 860, 822, 755 cm−1; H NMR (400 MHz, CDCl3): δ 7.87–7.78 (m, 6H arom.), 7.71 (broad
d, J=0.8 Hz, 2H arom.), 7.52–7.46 (m, 4H arom., H6,7, ∆δ=0.0030 ppm, J56=J78=8.2 Hz, J67=6.9 Hz,
J57=J68=1.2 Hz, J58=0.7 Hz), 7.39 (dd, J=8.4, 1.7 Hz, 2H arom.), 5.07–5.01 (m, 2H, CH-OMs),16 4.70
(d, 2H, J=11.8 Hz, CH2-2-naphthyl), 4.60 (d, 2H, J=11.8 Hz, CH2-2-naphthyl), 3.81 (pseudo dd, 2H,
J=11.2, 3.7 Hz, OCH2-CH),16 3.78 (pseudo dd, 2H, J=11.2, 5.7 Hz, OCH2-CH),16 3.03 (s, 6H, CH-
OMs); 13C NMR (100 MHz, CDCl3): δ 134.30 (Cipso arom.), 133.16 (Cipso arom.), 133.10 (Cipso arom.),
128.43 (CH arom.), 127.94 (CH arom.), 127.72 (CH arom.), 127.02 (CH arom.), 126.34 (CH arom.),
126.23 (CH arom.), 125.77 (CH arom.), 78.72 (CHOMs), 73.77 (CH2-2-naphthyl), 68.64 (OCH2-CH),
38.80 (OMs); HRMS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C28H30O8S2 558.1382
[M]+, found 558.1371 (3), 157.1 (13) [OCH2-2-naphthyl]+, 141.1 (100) [CH2-2-naphthyl]+, 127.1 (20)
26
26
26
26
[2-naphthyl]+; [α]26 −2.1, [α]
−2.1, [α]
−2.2, [α]
−1.2, [α]
+5.5 (c=1.9, CHCl3).
D
578
546
436
365
4.6. (2S,3S)-1,4-Bis(2-naphthylmethoxy)-2,3-diazidobutane 6c
A mixture of dimesylate 5c (0.28 g, 0.5 mmol) and sodium azide (0.114 g, 1.75 mmol) in DMSO
(1.5 mL) was stirred at 80°C for 1 day, cooled to ca. 20°C, and the white suspension was diluted
with water:brine 1:1 (3.5 mL). The aqueous layer was extracted three times with ethyl acetate and the
combined organic extracts were dried (MgSO4). Concentration in vacuo and chromatography of the
remaining brown-red liquid on silica gel (ethyl acetate:petroleum ether 5:95) afforded diazide 6c as a
colorless oil, which solidified after storage at ca. −20°C (0.192 g, 85%, Rf=0.21, ethyl acetate:petroleum
ether 10:90, mp 37–39°C); IR (neat, NaCl): ν 3056, 3024, 2908, 2864, 2103, 1344, 1271, 1125, 1107,
856, 818, 753 cm−1; 1H NMR (400 MHz, CDCl3): δ 7.88–7.77 (m, 6H arom.), 7.74 (broad s, 2H arom.),
7.52–7.44 (m, 4H arom., H6,7, ∆δ=0.0057 ppm, J56=J78=8.2 Hz, J67=6.9 Hz, J57=J68=1.2 Hz, J58=0.7
Hz), 7.42 (dd, J=8.4, 1.7 Hz, 2H arom.), 4.68 (s, 4H, CH2-2-naphthyl), 3.79–3.73 (m, 2H, CH-N3),16
3.72–3.62 (m, 4H, OCH2-CH);16 13C NMR (100 MHz, CDCl3): δ 134.77 (Cipso arom.), 133.18 (Cipso
arom.), 133.07 (Cipso arom.), 128.37 (CH arom.), 127.91 (CH arom.), 127.72 (CH arom.), 126.67 (CH
arom.), 126.24 (CH arom.), 126.07 (CH arom.), 125.59 (CH arom.), 73.65 (CH2-2-naphthyl), 69.59
(OCH2-CH), 61.02 (CH-N3); MS (EI, 70 eV) m/z (%): 452 (1.3) [M]+, 337 (4.8) [M−C9H7]+, 311
(1.8) [M−CH2-2-naphthyl]+, 226 (13) [M/2]+, 198 (66) [M/2−N2]+, 168 (27), 155 (68), 141 (100)
[CH2-2-naphthyl]+, 127 (42) [2-naphthyl]+, 115 (94) [C9H7]+; HRMS (FAB, m-nitrobenzylic alcohol
matrix) m/z (%): calcd for C26H25N6O2 [M+H]+ 453.2039, found 453.2022 (4), calcd for C26H25N4O2
425.1978 [M−N2+H]+, found 425.1974 (3), calcd for C26H27N4O2 427.2134 [M−N2+H2+H]+ (from
in situ reduction of one azide function), found 427.2125 (1), 198.0 [M/2−N2]+ (11), 141.0 [CH2-

A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
3565
24
24
24
24
2-naphthyl]+ (100); [α]24 −38.0, [α]
−39.6, [α]
−44.8, [α]
−74.4, [α]
−110.9 (c=5.5,
D
578
546
436
365
CHCl3). Anal. calcd for C26H24N6O2: C, 69.01; H, 5.35; N, 18.57. Found: C, 68.36; H, 5.36; N, 19.06.
4.7. (2S,3S)-1,4-Bis(2-naphthylmethoxy)-2,3-diaminobutane 3c
The same procedure as described for (2S,3S)-3b was followed. To a solution of diazide 6c (0.192 g,
0.42 mmol) in dry THF (5 mL) in a one-necked flask (100 mL) was added 10% Pd/C (0.03 g). The
mixture was hydrogenated at ca. 20°C and at atmospheric pressure for 18 h. The catalyst was then
removed by filtration over Celite and the filtrate was evaporated under vacuum to afford diamine 3c
as a colorless oil, which crystallized after prolonged storage at ca. −20°C yielding colorless crystals
(0.171 g, quant., mp 100–102°C); IR (Nujol, NaCl): ν 3369, 3052, 1349, 1261, 1102, 863, 821, 752
cm−1; 1H NMR (400 MHz, CDCl3): δ 7.84–7.76 (m, 6H arom.), 7.73 (broad s, 2H arom.), 7.49–7.43 (m,
4H arom., H6,7, ∆δ=0.0088 ppm, J56=J78=8.2 Hz, J67=6.9 Hz, J57=J68=1.2 Hz, J58=0.7 Hz), 7.42 (dd,
J=8.4, 1.5 Hz, 2H arom.), 4.63 (s, 4H, CH2-2-naphthyl), 3.52 (pseudo dd, 2H, J=9.3, 4.4 Hz, OCH2-
CH),16 3.43 (pseudo dd, 2H, J=9.3, 6.3 Hz, OCH2-CH),16 3.06–3.00 (m, 2H, CH-NH2),16 1.69 (s, 4H,
NH2); 13C NMR (100 MHz, CDCl3): δ 135.58 (Cipso arom.), 133.18 (Cipso arom.), 132.94 (Cipso arom.),
128.21 (CH arom.), 127.83 (CH arom.), 127.67 (CH arom.), 126.46 (CH arom.), 126.12 (CH arom.),
125.88 (CH arom.), 125.68 (CH arom.), 73.46 (CH2-2-naphthyl), 73.35 (OCH2-CH), 52.64 (CH-NH2);
MS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C26H29N2O2 401.2 [M+H]+, found 400
24
24
24
24
(3), 401 (100), 402 (31), 403 (6); [α]24 −10.7, [α]
−11.1, [α]
−12.7, [α]
−22.3, [α]
−37.2
D
578
546
436
365
(c=2.5, CHCl3).
For analytical purposes, diamine 3c (0.17 g, 0.42 mmol) was converted into its dibenzamide by
reaction with benzoyl chloride (0.146 mL, 1.26 mmol) and triethylamine (0.234 mL, 1.68 mmol) in
anhydrous dichloromethane (4.5 mL) as described for diamine 3b. Short plug chromatography on silica
gel (methanol:dichloromethane 1:99) afforded the dibenzamide as a white solid [0.237 g, 92%, Rf=0.11,
methanol:dichloromethane 1:99, mp 145–146°C (ethyl acetate:petroleum ether)]; IR (Nujol, NaCl): ν
1
3310, 3052, 1632, 1579, 1526, 1101, 1030, 853, 820, 724, 692 cm−1; H NMR (400 MHz, CDCl3): δ
7.85–7.80 (m, 2H of 2-naphthyl), 7.79–7.74 (m, 4H of 2-naphthyl), 7.70 (broad s, 2H of 2-naphthyl), 7.58
(pseudo dd, 4H, J=8.4, 1.2 Hz, H ortho of COPh), 7.52–7.45 (m, 4H of 2-naphthyl, H6,7, ∆δ=0.0080
ppm, J56=J78=8.2 Hz, J67=6.9 Hz, J57=J68=1.2 Hz, J58=0.7 Hz), 7.39 (dd, J=8.4, 1.7 Hz, 2H of 2-
naphthyl), 7.37 (ddt, 2H, J=7.9, 7.0, 1.2 Hz, H para of COPh), 7.30 (broad d, 2H, J=7.9 Hz, NH), 7.21
(dd pseudo t, 4H, J=7.9, 7.4, 1.6 Hz, H meta of COPh), 4.76–4.64 (m, 2H, CH-NH), 4.62 (s, 4H, CH2-2-
naphthyl), 3.79 (pseudo dd, 2H, J=9.7, 3.2 Hz, OCH2-CH), 3.73 (pseudo dd, 2H, J=9.7, 4.6 Hz, OCH2-
CH); 13C NMR (100 MHz, CDCl3): δ 167.57 (2C, CONH), 134.89 (2Cipso of 2-naphthyl), 133.89 (2Cipso
of COPh), 133.16 (2Cipso of 2-naphthyl), 133.06 (2Cipso of 2-naphthyl), 131.42 (2Cpara of COPh), 128.41
(4Cmeta of COPh and 2CH of 2-naphthyl), 127.93 (2CH of 2-naphthyl), 127.72 (2CH of 2-naphthyl),
126.99 (2CH of 2-naphthyl), 126.91 (4Cortho of COPh), 126.28 (2CH of 2-naphthyl), 126.14 (2CH of 2-
naphthyl), 125.87 (2CH of 2-naphthyl), 73.67 (2C, CH2-2-naphthyl), 68.98 (2C, OCH2-CH), 51.05 (2C,
CH-NH); MS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C40H37N2O4 609.3 [M+H]+,
24
found 608 (4), 609 (100), 610 (46), 611 (11), 451 (21) [M−2-naphthylCH2O]+; [α]24 −72.6, [α]
D
578
24
24
24
−76.3, [α]
−86.9, [α]
−155.1, [α]
−265.3 (c=1.0, CHCl3). Anal. calcd for C40H36N2O4: C,
546
436
365
78.92; H, 5.96; N, 4.60. Found: C, 79.02; H, 6.24; N, 4.63.
4.8. (2S,3S)-1,4-Bis(triphenylmethoxy)-2,3-diazidobutane 6d
A mixture of diol 7 (0.103 g, 0.6 mmol) and tritylpyridinium tetrafluoroborate (0.589 g, 1.44 mmol)
in dry acetonitrile (2.5 mL) was stirred at 65°C for 8 h, cooled to ca. 20°C and the slight yellow solution

3566
A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
was evaporated. The residue was diluted with petroleum ether (6 mL) to precipitate the pyridinium
tetrafluoroborate, and ca. 15% aq. NaCl (3 mL). The aqueous layer was extracted three times with ether
and the combined organic extracts were dried (MgSO4). Concentration in vacuo and chromatography of
the crude product on silica gel (tert-butyl methyl ether:petroleum ether 2:98) afforded diazide 6d as a
colorless oil (0.323 g, 82%, Rf=0.16, ethyl acetate:petroleum ether 2:98, mp 53–55°C); IR (neat, NaCl):
ν 3087, 3060, 3032, 2928, 2876, 2856, 2099, 1735, 1598, 1491, 1448, 1276, 1087, 1079, 907, 766,
1
743, 734, 703, 632 cm−1; H NMR (400 MHz, CDCl3): δ 7.40–7.35 (m, 12H), 7.29–7.20 (m, 18H),
3.52–3.45 (m, 2H, CH-N3),16 3.27 (pseudo dd, 2H, J=9.9, 4.4 Hz, CH2O),16 3.13 (pseudo dd, 2H, J=9.9,
6.8 Hz, CH2O);16 13C NMR (100 MHz, CDCl3): δ 143.37 (6Cipso), 128.53 and 127.93 (12Cmeta and
12Cortho), 127.22 (6Cpara), 87.43 (2C, C(Ph)3), 63.47 (2C, CH2O), 62.00 (2C, CH-N3); HRMS (FAB,
m-nitrobenzylic alcohol matrix) m/z (%): calcd for C42H37N6O2 657.2978 [M+H]+, found 657.2923
24
24
24
(0.14), 579.2 (0.15) [M−Ph]+, 243.1 (100) [Ph3C]+; [α]24 +8.4, [α]
+9.0, [α]
+10.4, [α]
D
578
546
436
24
+22.0, [α]
+47.1 (c=2.0, CHCl3). Anal. calcd for C42H36N6O2: C, 76.81; H, 5.52; N, 12.80. Found:
365
C, 76.85; H, 5.81; N, 12.73.
4.9. (2S,3S)-1,4-Bis(triphenylmethoxy)-2,3-diaminobutane 3d
The same procedure as described for (2S,3S)-3b was followed. To a solution of diazide 6d (0.262
g, 0.4 mmol) in dry THF (6 mL) in a one-necked flask (100 mL) was added 20% Pd(OH)2/C (humid:
commercial Pearlman’s catalyst) (0.035 g). The mixture was hydrogenated at ca. 20°C and at atmospheric
pressure for 18 h. The catalyst was mostly removed by filtration over Celite and the filtrate was evaporated
in vacuo to afford diamine 3d as a dark syrup which became a dark foam under vacuum (0.244 g,
quant., mp 51–52°C). The compound was contaminated with a small amount of colloidal Pd, which
could not be removed by stirring in the presence of activated carbon or by further filtrations over Celite
and polymers with pores of 0.5 µm; IR (Nujol, NaCl): ν 3381, 3086, 3057, 3031, 3022, 1961, 1596,
1490, 1449, 1220, 1154, 1071, 899, 764, 746, 706, 633 cm−1; 1H NMR (400 MHz, CDCl3): δ 7.40–7.35
(m, 12H), 7.28–7.18 (m, 18H), 3.10 (pseudo dd, 2H, J=8.0, 3.4 Hz, CH2O), 2.98–2.88 (m, 4H, CH-NH2
and CH2O), 1.41 (broad s, 4H, CH-NH2); 13C NMR (100 MHz, CDCl3): δ 144.00 (6Cipso), 128.63 and
127.80 (12Cmeta and 12Cortho), 126.97 (6Cpara), 86.51 (2C, CPh3), 66.18 (2C, CH2O), 53.26 (2C, CH-
NH2); HRMS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C42H41N2O2 605.3168 [M+H]+,
found 605.3174, 243.1 (100) [Ph3C]+; [α] could not be measured due to traces of colloidal Pd.
For analytical purposes, diamine 3d (0.091 g, 0.15 mmol) was converted into its dibenzamide by
reaction with benzoyl chloride (0.055 mL, 0.47 mmol) and triethylamine (0.085 mL, 0.61 mmol) in
anhydrous dichloromethane (2 mL) as described for diamine 3b. Short plug chromatography on silica gel
(ethyl acetate:petroleum ether 1:9) afforded the dibenzamide as a white powder [0.113 g, 93%, Rf=0.15,
ethyl acetate:petroleum ether 1:4, mp 225–226°C (toluene:petroleum ether)]; IR (Nujol, NaCl): ν 3312
(broad), 3056, 1703, 1642, 1532, 1487, 1074, 706 cm−1; 1H NMR (400 MHz, CDCl3): δ 7.69–7.64 (m,
4H, H ortho of COPh), 7.47 (ddt, 2H, J=8.2, 6.5, 1.3 Hz, H para of COPh), 7.39 (pseudo tt, 4H, J=8.1,
1.6 Hz, H meta of COPh), 7.38–7.31 (m, 12H of Tr), 7.22–7.14 (m, 18H of Tr and 2H of NH), 4.79–4.71
(m, 2H, CH-NH), 3.53 (pseudo dd, 2H, J=10.0, 2.2 Hz, CH2O), 3.26 (pseudo dd, 2H, J=10.0, 2.0 Hz,
CH2O); 13C NMR (100 MHz, CDCl3): δ 168.21 (2C, CONH), 144.01 (6Cipso of Tr), 134.06 (2Cipso of
COPh), 131.50 (2Cpara of COPh), 128.51 (4Cmeta of COPh), 128.46 and 127.97 (12Cmeta and 12Cortho
of Tr), 127.15 (4Cortho of COPh), 127.01 (6Cpara of Tr), 86.76 (2C, OCPh3), 61.90 (2C, OCH2CH),
51.71 (2C, CH-NH); MS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C56H49N2O4 813.4
24
24
24
[M+H]+, found 813 (0.2) [M+H]+, 243 (100) [Ph3C]+; [α]24 −3.0, [α]
−3.2, [α]
−3.9, [α]
D
578
546
436
−6.7 (c=1.7, CHCl3). Anal. calcd for C56H48N2O4: C, 82.73; H, 5.95; N, 3.45. Found: C, 82.52; H, 6.19;
N, 3.43.

A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
3567
4.10. (2S,3S)-1,4-Bis[(t-butyldimethylsilyl)oxy]-2,3-diazidobutane 6e
tert-Butyldimethylsilyl chloride (0.362 g, 2.4 mmol) was added to a solution of diol 7 (0.172 g, 1.0
mmol) and imidazole (0.350 g, 5.1 mmol) in anhydrous DMF (2 mL) at 0°C. After 24 h of reaction at
0°C in the refrigerator without stirring, water was added. The mixture was extracted three times with
petroleum ether and the combined organic extracts were subsequently washed with water and dried
(Na2SO4). Concentration in vacuo and chromatography of the crude product on silica gel (petroleum
ether) afforded diazide 6e as a colorless oil (0.393 g, 98%, Rf=0.19, ethyl acetate:petroleum ether 1:99);
1
IR (neat, NaCl): ν 2956, 2931, 2886, 2859, 2106, 1472, 1465, 1259, 1114, 1006, 839, 778 cm−1; H
NMR (400 MHz, CDCl3): δ 3.85–3.80 (m, 4H, CH2O), 3.60–3.54 (m, 2H, CH-N3), 0.91 (s, 18H, t-
Bu), 0.11 (s, 12H, SiMe2); 13C NMR (100 MHz, CDCl3): δ 63.28 (2C, CH2O), 62.33 (2C, CH-N3),
25.76 (6C, C(CH3)3), 18.17 (2C, C(CH3)3), −5.56 (2C, Si-CH3), −5.57 (2C, Si-CH3); HRMS (FAB,
m-nitrobenzylic alcohol matrix) m/z (%): calcd for C16H37N6O2Si2 401.2517 [M+H]+, found 401.2517
(3), calcd for C15H33N6O2Si2 385.2204 [M−Me]+, found 385.2211 (11), 343.2 (52) [M−t-Bu]+, 330.2
(12.5) [M−N2−C3H6]+, 315.2 (45) [M−N2−t-Bu]+, 287.1 (7) [M−2N2−t-Bu]+, 272.1 (13) [M−2N2−t-
Bu−Me]+, 230.1 (12) [M−2N2−2t-Bu]+, 200.1 (4), [M/2]+, 147.1 (65), 116.1 (54) [HSiMe2t-Bu]+, 89.0
25
25
25
25
(100); [α]25 −36.5, [α]
−38.2, [α]
−43.0, [α]
−69.8, [α]
−99.9 (c=5.0, CHCl3). Anal.
D
578
546
436
365
calcd for C16H36N6O2Si2: C, 47.96; H, 9.06; N, 20.97. Found: C, 47.87; H, 8.78; N, 21.34.
4.11. (2S,3S)-1,4-Bis[(t-butyldimethylsilyl)oxy]-2,3-diaminobutane 3e
The same procedure as described for (2S,3S)-3b was followed. To a solution of diazide 6e (0.25 g, 0.62
mmol) in dry THF (9 mL) in a one-necked flask (250 mL) was added 10% Pd/C (0.08 g). The mixture was
hydrogenated at ca. 20°C and at atmospheric pressure for 18 h. Most catalyst was removed by filtration
over Celite and the filtrate was evaporated under vacuum to afford diamine 3e as a slightly black syrup
(0.218 g, quant.). The compound was contaminated with a small amount of colloidal Pd, which could not
be removed; IR (neat, NaCl): ν 3379 (broad), 2955, 2931, 2888, 2858, 1588, 1470, 1390, 1361, 1256,
1
1098, 1006, 838, 777, 667 cm−1; H NMR (400 MHz, CDCl3): δ 3.63 (pseudo dd, 2H, J=9.9, 4.4 Hz,
CH2O),16 3.55 (pseudo dd, 2H, J=9.9, 6.1 Hz, CH2O),16 2.86–2.78 (m, 2H, CH-NH2),16 1.51 (broad
s, 4H, CH-NH2), 0.90 (s, 18H, t-Bu), 0.06 (s, 12H, SiMe2); 13C NMR (100 MHz, CDCl3): δ 66.39
(2C, CH2O), 54.25 (2C, CH-NH2), 25.91 (6C, C(CH3)3), 18.25 (2C, C(CH3)3), −5.39 (2C, Si-CH3),
−5.40 (2C, Si-CH3); HRMS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C16H41N2O2Si2
349.2707 [M+H]+, found 349.2712 (50) [M+H]+, 291.2 (3) [M−t-Bu]+, 174.1 (31) [M/2]+, 147.1 (9),
136.1 (21), 116.1 (43) [HSiMe2t-Bu]+; [α] could not be measured due to traces of colloidal Pd.
In the HRMS spectrum, the base peak was measured at m/z=359.2556 (calcd for
C17H39N2O2Si2=359.2550) which would fit to [M0+H]+ where M0 is an imidazoline derivative.
Although such a compound was not detected by NMR, it might be highly ionizable and present in a
small amount in the crude diamine.
For analytical purposes, diamine 3e (0.070 g, 0.2 mmol) was converted into its dibenzamide [(2S,3S)-
N,N0-dibenzoyl-1,4-bis[(t-butyldimethylsilyl)oxy]-2,3-diaminobutane] by reaction with benzoyl chlor-
ide (0.070 mL, 0.60 mmol) and triethylamine (0.110 mL, 0.80 mmol) in anhydrous dichloromethane (2
mL) as described for diamine 3b. Chromatography on silica gel (gradient elution from petroleum ether to
petroleum ether:EtOAc 9:1) afforded dibenzamide as colorless crystals (0.103 g, 93%, Rf=0.26, CH2Cl2
(100%), mp 154–155°C); IR (Nujol, NaCl): ν 3285 (broad), 3064, 3032, 1639, 1605, 1538, 1491, 1342,
1254, 1135, 1104, 1013, 837, 779, 693 cm−1; 1H NMR (400 MHz, CDCl3): δ 7.76–7.71 (m, 4H, H ortho
of COPh), 7.46 (ddt, 2H, J=8.4, 6.2, 1.3 Hz, H para of COPh), 7.42–7.36 (m, 4H, H meta of COPh),
7.22 (broad d, 2H, J=7.8 Hz, NH), 4.58–4.48 (m, 2H, CH-NH), 3.96 (pseudo dd, 2H, J=10.7, 2.3 Hz,

3568
A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
CH2O), 3.92 (pseudo dd, 2H, J=10.7, 3.1 Hz, CH2O), 0.93 (s, 18H, C(CH3)3), 0.10 (s, 6H, Si-CH3),
0.08 (s, 6H, Si-CH3); 13C NMR (100 MHz, CDCl3): δ 167.87 (2C, CONH), 134.15 (2Cipso of COPh),
131.48 (2Cpara of COPh), 128.55 (4Cmeta of COPh), 126.90 (4Cortho of COPh), 62.14 (2C, OCH2CH),
52.30 (2C, CH-NH), 25.89 (6C, C(CH3)3), 18.27 (2C, C(CH3)3), −5.42 (2C, Si-CH3), −5.45 (2C, Si-
CH3); MS (FAB, m-nitrobenzylic alcohol matrix) m/z (%): calcd for C30H49N2O4Si2 557.32 [M+H]+,
found 557 (80) [M+H]+, 541 (12) [M−Me]+, 499 (97) [M−t-Bu]+, 425 (100) [M−OSiMe2t-Bu]+, 278
20
20
20
(16) [M/2]+; [α]20 −91.1, [α]
−95.2, [α]
−109.5, [α]
−199.6 (c=1.99, CHCl3). Anal. calcd
D
578
546
436
for C30H48N2O4Si2: C, 64.70; H, 8.69; N, 5.03. Found: C, 65.96; H, 8.75; N, 4.93.
4.12. (2S,3S)-1,4-Bis[(t-butyldiphenylsilyl)oxy]-2,3-diazidobutane 6f
tert-Butylchlorodiphenylsilane (600 µL, 0.632 g, 2.3 mmol) was added dropwise to a solution of diol
7 (0.172 g, 1.0 mmol) and imidazole (0.334 g, 4.9 mmol) in anhydrous DMF (2 mL) at 0°C. After
24 h reaction at 0°C in the refrigerator without stirring, water was added. The mixture was extracted
three times with petroleum ether and the combined organic extracts were subsequently washed with
water and dried (Na2SO4). Concentration in vacuo and chromatography of the crude product on silica
gel (gradient elution from petroleum ether to tert-butyl methyl ether:petroleum ether 2:98) afforded
diazide 6f as a colorless oil (0.610 g, 94%, Rf=0.41, ethyl acetate:petroleum ether 2:98); IR (neat,
NaCl): ν 3072, 3051, 2958, 2932, 2859, 2106, 1590, 1471, 1428, 1263, 1112, 823, 740, 703 cm−1;
1H NMR (400 MHz, CDCl3): δ 7.67–7.62 (m, 8H, ortho of SiPh2), 7.48–7.35 (m, 12H, para and meta
of SiPh2), 3.82–3.77 (m, 4H, CH2O), 3.66–3.59 (m, 2H, CH-N3), 1.06 (s, 18H, t-Bu); 13C NMR (100
MHz, CDCl3): δ 135.53 (4Cmeta), 135.50 (4Cmeta), 132.62 (4Cipso), 129.97 (4Cpara), 127.87 (8Cortho),
63.83 (2C, CH2O), 62.42 (2C, CH-N3), 26.70 (6C, C(CH3)3), 19.12 (2C, C(CH3)3); HRMS (FAB, m-
nitrobenzylic alcohol matrix) m/z (%): calcd for C36H45N6O2Si2 649.3143 [M+H]+, found 649.3094
(1), calcd for C36H47N4O2Si2 623.3238 [M−N2+H2+H]+ (from in situ reduction of one azide function),
found 623.3234 (6), calcd for C32H35N6O2Si2 591.2360 [M−C4H9]+, found 591.2372 (10), 571.3 (8)
24
24
24
24
[M−Ph]+, 135.1 (100); [α]24 −14.1, [α]
−14.7, [α]
−16.4, [α]
−26.1, [α]
−34.0 (c=1.0,
D
578
546
436
365
CHCl3). Anal. calcd for C38H44N6O2: C, 66.63; H, 6.83; N, 12.95. Found: C, 66.19; H, 6.75; N, 13.07.
4.13. (2S,3S)-1,4-Bis[(t-butyldiphenylsilyl)oxy]-2,3-diaminobutane 3f
The same procedure as described for (2S,3S)-3b was followed. To a solution of diazide 6f (0.100 g,
0.16 mmol) in dry THF (3 mL) in a one-necked flask (50 mL) was added 10% Pd/C (0.03 g). The mixture
was hydrogenated at ca. 20°C and at atmospheric pressure for 18 h. The catalyst was mostly removed by
filtration over Celite and the filtrate was evaporated under vacuum to afford diamine 3f as a slightly black
syrup (0.095 g, quant.). The compound was contaminated with a small amount of colloidal Pd, which
could not be removed; IR (neat, NaCl): ν 3384 (broad), 3071, 3050, 2959, 2931, 2892, 2858, 1589,
1
1471, 1428, 1391, 1361, 1262, 1111, 823, 740, 704 cm−1; H NMR (400 MHz, CDCl3): δ 7.66–7.59
(m, 8H, ortho of SiPh2), 7.44–7.31 (m, 12H, para and meta of SiPh2), 3.62 (pseudo dd, 2H, J=10.0,
4.7 Hz, CH2O),16 3.55 (pseudo dd, 2H, J=10.0, 6.1 Hz, CH2O),16 2.95–2.88 (m, 2H, CH-NH2),16 1.43
(broad s, 4H, CH-NH2), 1.04 (s, 18H, C(CH3)3); 13C NMR (100 MHz, CDCl3): δ 135.55 (4Cmeta),
135.54 (4Cmeta), 133.43 (2Cipso), 133.40 (2Cipso), 129.72 (2Cpara), 129.70 (2Cpara), 127.71 (8Cortho),
66.84 (2C, CH2O), 53.84 (2C, CH-NH2), 26.89 (6C, C(CH3)3), 19.25 (2C, C(CH3)3); HRMS (FAB,
m-nitrobenzylic alcohol matrix) m/z (%): calcd for C36H49N2O2Si2 597.3333 [M+H]+, found 597.3339
(41) [M+H]+, 451.3 (4), 355.1 (4), 327.0 (7) [M−CH2OSiPh2t-Bu], 310.1 (5), 298.2 (6) [M/2]+, 281.1
(25) [M/2−NH3]+, 240.1 (8) [HSiPh2t-Bu]+, 221.1 (14) [M/2−Ph]+, 197.1 (50), 135.1 (100); [α] could
not be measured due to traces of colloidal Pd.

A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
3569
As for 3e, in the HRMS spectrum, an extra peak with an added mass of 10 was visible (m/z=607.3161,
rel. int.: 34%, calcd for C37H47N2O2Si2=607.3176) which would also fit an imidazoline derivative. Such
a compound was not detected by NMR and probably present in small amounts in the crude diamine.
Moreover, the peak at 607 was always present in the recorded mass spectrum using another matrix
(glycerol) with the same intensity relatively to that of the peak at 597.
Diamine 3f was converted into di(p-bromobenzamide) [(2S,3S)-N,N0-di(p-bromobenzoyl)-1,4-
bis[(t-butyldiphenylsilyl)oxy]-2,3-diaminobutane]: reaction of diamine (0.036 g, 0.06 mmol) with
p-bromobenzoyl chloride (0.04 g, 0.18 mmol) and triethylamine (34 µL, 0.24 mmol) in anhydrous
dichloromethane (0.48 mL) for 1 h at 0°C and then 3.5 h at ca. 20°C. Chromatography on silica gel
(1.6 g, solid transfer of crude product, elution with petroleum ether:EtOAc 95:5) afforded bisamide as
a white powder (0.042 g, 72%, Rf=0.35, petroleum ether:EtOAc 4:1, mp 122°C); IR (Nujol, KBr): ν
1
3275 (broad), 3070, 3048, 1637, 1591, 1534, 1428, 1112, 1012, 740, 702, 608, 505 cm−1; H NMR
(400 MHz, CDCl3): δ 7.59–7.53 (m, 8H arom.), 7.53–7.44 (m, 8H arom.), 7.43–7.35 (m, 4H arom.),
7.35–7.26 (m, 8H arom.), 7.06 (broad dm, 2H, J=7.6 Hz, NH), 4.63–4.53 (m, 2H, CH-NH), 3.89 (dd,
2H, J=11.0, 1.4 Hz, CH2O), 3.80 (broad dd, 2H, J=11.0, 0.8 Hz, CH2O), 1.06 (s, 18H, C(CH3)3);
13C NMR (100 MHz, CDCl3): δ 166.93 (2C, CONH), 135.55 (2CHortho of SiPh2), 135.46 (2CHortho
of SiPh2), 132.83 and 132.70 and 132.56 (2Cipso of SiPh2 and Cipso α to Br), 131.79 (2CH β to
CONH), 130.06 (CHpara of SiPh2), 129.99 (CHpara of SiPh2), 128.48 (2CH β to Br), 127.91 (2CHmeta
of SiPh2), 127.89 (2CHmeta of SiPh2), 126.26 (Cipso α to CONH), 62.49 (2C, OCH2CH), 52.28 (2C,
CH-NH), 26.93 (6C, C(CH3)3), 19.30 (2C, C(CH3)3); HRMS (FAB, m-nitrobenzylic alcohol matrix)
m/z (%): calcd for C50H55Br2N2O4Si2 963.2054 [M+H]+, found 963.2091 (6) [M+H]+, 905.1 (32)
[M−t-Bu], 885.1 (13) [M−Ph], 707.1 (10) [M−OSiPh2t-Bu], 199.0 (46) [NHCOp-81Br-C6H4], 197.0
(56) [NHCOp-79Br-C6H4], 184.9 (66) [COp-81Br-C6H4], 182.9 (70) [COp-79Br-C6H4], 135.0 (100);
20
20
20
20
[α]20 −30.4, [α]
−31.8, [α]
−36.9, [α]
−68.7, [α]
−127.6 (c=1.4, CHCl3).
D
578
546
436
365
Acknowledgements
Financial support by the Deutsche Forschungsgemeinschaft is gratefully acknowledged. We would
also like to thank Mrs Isabelle Plessis and Mr Hervé Léon for their substantial experimental work and
the Centre Régional de Mesures Physiques de l’Ouest for mass spectra.
References
1. Noyori, R. Asymmetric Catalysis in Organic Synthesis; Wiley: New York, 1994; Catalytic Asymmetric Synthesis; Ojima,
I., Ed.; VCH: Weinheim, 1993.
2. (a) Tomioka, K. Synthesis 1990, 541–549. (b) Togni, A.; Venanzi, L. M. Angew. Chem., Int. Ed. Engl. 1994, 33, 497–526.
3. (a) Whitesell, J. K. Chem. Rev. 1989, 89, 1581–1590. (b) Nantz, M. H.; Lee, D. A.; Bender, D. M.; Roohi, A. H. J. Org.
Chem. 1992, 57, 6653–6657. (c) Kotsuki, H.; Kuzume, H.; Gohda, T.; Fukuhara, M.; Ochi, M.; Oishi, T.; Hirama, M.;
Shiro, M. Tetrahedron: Asymmetry 1995, 6, 2227–2236.
4. Scheurer, A.; Mosset, P.; Saalfrank, R. W. Tetrahedron: Asymmetry 1997, 8, 1243–1251 and 3161.
5. Seebach, D.; Kalinowski, H.-O.; Bastani, B.; Crass, G.; Daum, H.; Dörr, H.; DuPreez, N. P.; Ehrig, V.; Langer, W.; Nüssler,
C.; Oei, H.-A.; Schmidt, M. Helv. Chim. Acta 1977, 60, 301–325.
6. Diols 4a and 4b are commercially available [for a synthesis of 4a, see: Mash, E. A.; Nelson, K. A.; Van Deusen, S.;
Hemperly, S. B. Org. Synth., Coll. Vol. VIII 1993, 155–161]. Diol 4c was used for diastereoselective cyclopropanations
[see: Mash, E. A.; Hemperly, S. B.; Nelson, K. A.; Heidt, P. C.; Van Deusen, S. J. Org. Chem. 1990, 55, 2045–2055].
However, the experimental and spectroscopic data of 4c were not reported. 4c was prepared from 2,3-O-isopropylidene-L-
threitol [2,3-O-Isopropylidene-L-threitol is readily available from (+)-diethyl tartrate in two steps. We used the procedure
described by Holy, A. (Collect. Czech. Chem. Commun. 1982, 47, 173–189; acetalization by triethyl orthoformate and

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A. Scheurer et al. / Tetrahedron: Asymmetry 10 (1999) 3559–3570
acetone followed by reduction of the ethyl ester groups by sodium borohydride in absolute ethanol)] by double alkylation
with 2-(bromomethyl)naphthalene followed by acetonide cleavage (see Experimental).
7. Vicinal diazides are interesting compounds in their own right: for reactions of analogous diazides with C60 affording chiral
bisazafulleroids, see: Shen, C. K.-F.; Chien, K.-M.; Juo, C.-G.; Her, G.-R.; Luh, T.-Y. J. Org. Chem. 1996, 61, 9242–9244.
5
8. Although reduction of diazides 6a and 6b to diamines 3a and 3b was reported with LiAlH4 [see also: Oishi, T.; Hirama,
M. Tetrahedron Lett. 1992, 33, 639–642], catalytic hydrogenation was found to be more efficient and convenient. In the
case of diazide 6c, reaction with LiAlH4 resulted in cleavage of β-naphthylmethoxy groups to 2-methylnaphthalene. Use
of other reducing agents (ammonium formate, Pd/C, MeOH or sodium borohydride in the presence of copper sulfate) led
to complete decomposition.
9. The catalytic hydrogenation of diazide 6c to afford diamine 3c was also successful in isopropanol at 45°C, but THF was
found to be more convenient. The catalytic hydrogenation of diazide 6a to diamine 3a was carried out in methanol, see
Ref. 4, but THF is also an excellent solvent.
10. Ditritylation of diol 5d using standard conditions (excess trityl chloride and Et3N, cat. DMAP, refluxing THF) only
afforded a very low yield of 6d (14%).
11. Hanessian, S.; Staub, A. P. A. Tetrahedron Lett. 1973, 3555–3558.
12. In this case, palladium on carbon was a totally ineffective catalyst. However, when Pearlman’s catalyst was used, diamine
6d was contaminated by colloidal palladium, which could not be removed.
13. Corey, E. J.; Venkateswarlu, A. J. Am. Chem. Soc. 1972, 94, 6190–6191.
14. Hanessian, S.; Lavallée, P. Can. J. Chem. 1975, 53, 2975–2977.
15. Recently, the vicinal diamines 3a–d were used for the preparation of salen Mn(III) complexes as catalysts for the
enantioselective epoxidation of unfunctionalized alkenes: Scheurer, A.; Mosset, P.; Spiegel, M.; Saalfrank, R. W.
Tetrahedron 1999, 55, 1063–1078.
1
16. For the H NMR spectrum, a symmetrical six spin ABCC0A0B0 system was observed. Simulation afforded the NMR
parameters shown in Table 1.
Table 1
Chemical shifts and non equal to zero coupling constants of the ABCC0A0B0 system observed in 1H
NMR spectra of compounds 3b,c,e,f, 4c, 5b,c, 6b–d and 8
17. Crude acetonide 8 was obtained along with residual 2-(bromomethyl)naphthalene and was used as such for the next step.
Subsequent acetonide cleavage yielded crystalline diol 4c which was easily purified.