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T. Korenaga et al. / Tetrahedron: Asymmetry 19 (2008) 695–700
4.1.2. (1S,2S)-1,2-Bis(4-isopropoxy-2,3,5,6-tetrafluorophen-
yl)ethane-1,2-diamine (S,S)-3b. Compound (S,S)-3b was
prepared from (S,S)-2 (19.6 mg, 0.0500 mmol), KOH
(56.1 mg, 1.00 mmol), and 2-propanol (1.0 mL) in 98%
was prepared from (S,S)-2 (19.6 mg, 0.0500 mmol), KOH
(56.1 mg, 1.00 mmol), and 2,2-dimethyl-1-propanol
(2.00 g, 22.7 mmol) in 91% yield (24.0 mg, 0.0454 mmol)
by the procedure described for (S,S)-3a at 55 °C for 18 h:
30
yield (23.2 mg, 0.0491 mmol) by the procedure described
yellow oil; ½aꢂD ¼ ꢁ89:2 (c 0.45, MeOH); IR (neat, NaCl
30
for (S,S)-3a: colorless oil; ½aꢂD ¼ ꢁ92:5 (c 0.21, MeOH);
plate, cmꢁ1) 3387, 3310, 2962, 1651, 1504, 1366, 1265,
IR (neat, NaCl plate, cmꢁ1) 3387, 3325, 2986, 1651,
1134, 986; H NMR (300 MHz, CDCl3) d 4.45 (s, 2H),
1
1
1489, 1381, 1242, 1103, 980; H NMR (300 MHz, CDCl3)
3.79 (s, 4H), 2.08 (br, 4H), 1.01 (s, 18H); 13C NMR
(75 MHz, CDCl3 (except for C6F4)) d 84.9, 52.6, 32.7,
26.0; 19F NMR (282 MHz, CDCl3) d ꢁ145.9 to ꢁ145.8
(m, 4F), ꢁ157.9 to ꢁ157.8 (m, 4F); Anal. Calcd for
C24H28F8N2O2: C, 54.54; H, 5.34; N, 5.30; Found: C,
54.76; H, 5.54; N, 4.97. HLPC analysis: hexane/i-PrOH/
Et2NH (70:30:0.4), 0.5 mL minꢁ1, UV 254 nm, retention
time (tR); (S,S)-3e: 16.1 min (>99%), (R,R)-3e: 24.5 min
(0%).
d 4.47 (m, 2H), 4.42 (s, 2H), 2.03 (br, 4H), 1.29 (d,
J = 6.2 Hz, 12H); 13C NMR (75 MHz, CDCl3 (except for
C6F4)) d 78.0, 52.8, 22.1; 19F NMR (282 MHz, CDCl3) d
ꢁ145.9 to ꢁ145.8 (m, 4F), ꢁ157.0 to ꢁ156.9 (m, 4F); Anal.
Calcd for C20H20F8N2O2: C, 50.85; H, 4.27; N, 5.93;
Found: C, 50.58; H, 4.26; N, 5.75. HLPC analysis:
hexane/i-PrOH/Et2NH (70:30:0.2), 0.5 mL minꢁ1
, UV
254 nm, retention time (tR); (S,S)-3b: 18.1 min (>99%),
(R,R)-3b: 32.6 min (0%).
4.1.6. (1S,2S)-1,2-Bis(4-cyclopentyloxy-2,3,5,6-tetrafluoro-
phenyl)ethane-1,2-diamine (S,S)-3f. Compound (S,S)-3f
was prepared from (S,S)-2 (9.8 mg, 0.0250 mmol), KOH
(28.1 mg, 0.500 mmol), and cyclopentanol (0.70 mL) in
82% yield (10.7 mg, 0.0204 mmol) by the procedure
4.1.3. (1S,2S)-1,2-Bis(4-(pentan-3-yloxy)-2,3,5,6-tetrafluoro-
phenyl)ethane-1,2-diamine (S,S)-3c. Compound (S,S)-3c
was prepared from (S,S)-2 (19.6 mg, 0.0500 mmol), KOH
(56.1 mg, 1.00 mmol), and 3-pentanol (1.0 mL) in 97% yield
(25.5 mg, 0.0483 mmol) by the procedure described for
described for (S,S)-3a at 50 °C for 6 h: yellow oil;
16
31
(S,S)-3a at 50 °C for 6 h: yellow oil; ½aꢂD ¼ ꢁ51:4 (c 1.6,
½aꢂD ¼ ꢁ77:2 (c 0.54, MeOH); IR (neat, NaCl plate,
MeOH); IR (neat, NaCl plate, cmꢁ1) 3387, 3302, 2970,
cmꢁ1) 3387, 3310, 2939, 1651, 1489, 1373, 1242, 1134,
1
1
1651, 1489, 1381, 1242, 1134, 980; H NMR (300 MHz,
980; H NMR (300 MHz, CDCl3) d 4.78–4.84 (m, 2H),
CDCl3) d 4.41 (s, 2H), 4.13 (quint, J = 5.7 Hz, 2H), 2.07
(br, 4H), 1.57–1.61 (m, 8H), 0.91–0.97 (m, 12H); 13C NMR
(75 MHz, CDCl3 (except for C6F4)) d 87.8, 52.8, 26.2, 9.1;
19F NMR (282 MHz, CDCl3) d ꢁ146.0 to ꢁ145.9 (m 4F),
ꢁ156.9 to ꢁ156.8 (m, 4F); Anal. Calcd for C24H28F8N2O2:
C, 54.54; H, 5.34; N, 5.30; Found: C, 54.41; H, 5.47; N,
5.07. HLPC analysis: hexane/i-PrOH/Et2NH (70:30:0.4),
0.5 mL minꢁ1, UV 254 nm, retention time (tR); (S,S)-3c:
18.1 min (>99%), (R,R)-3c: 31.0 min (0%).
4.41 (s, 2H), 2.08 (br, 4H), 1.61–1.83 (m, 16H); 13C NMR
(75 MHz, CDCl3 (except for C6F4)) d 87.1, 52.8, 32.7,
23.2; 19F NMR (282 MHz, CDCl3) d ꢁ146.0 to ꢁ145.9
(m, 4F), ꢁ157.2 to ꢁ157.1 (m, 4F); Anal. Calcd for
C24H24F8N2O2: C, 54.96; H, 4.61; N, 5.34; Found: C,
55.14; H, 4.91; N, 4.98. HLPC analysis: hexane/i-PrOH/
Et2NH (70:30:0.4), 0.5 mL minꢁ1, UV 254 nm, retention
time (tR); (S,S)-3f: 21.7 min (>99%), (R,R)-3f: 37.0 min
(0%).
4.1.4. (1S,2S)-1,2-Bis(4-benzhydryloxy-2,3,5,6-tetrafluoro-
phenyl)ethane-1,2-diamine (S,S)-3d. A mixture of (S,S)-2
(4.9 mg, 0.0125 mmol), KOH (14.0 mg, 0.250), and benzhy-
drol (0.500 g, 2.71 mmol) in DMF (0.10 mL) was stirred at
50 °C for 24 h. To the reaction mixture was added water,
and the organic layer was extracted with Et2O
(3 ꢀ 2 mL). The combined organic extract was washed
with brine. The organic layer was dried over MgSO4, and
concentrated under reduced pressure to afford a crude
oil, which was purified by column chromatography (neu-
4.1.7. (1S,2S)-1,2-Bis(4-cyclohexyloxy-2,3,5,6-tetrafluoro-
phenyl)ethane-1,2-diamine (S,S)-3g. Compound (S,S)-3g
was prepared from (S,S)-2 (19.6 mg, 0.0500 mmol), KOH
(56.1 mg, 1.00 mmol), and cyclohexanol (1.4 mL) in 77%
yield (21.2 mg, 0.0384 mmol) by the procedure described
32
for (S,S)-3a at 50 °C for 6 h: yellowish oil; ½aꢂD ¼ ꢁ80:2
(c 0.13, MeOH); IR (neat, NaCl plate, cmꢁ1) 3389, 3317,
2939, 1651, 1489, 1373, 1242, 1134, 980; 1H NMR
(300 MHz, CDCl3) d 4.41 (s, 2H), 4.14–4.21 (m, 2H),
1.98 (br, 4H), 1.57–1.88 (m, 8H), 1.51–1.57 (m, 6H),
1.25–1.35 (m, 6H); 13C NMR (75 MHz, CDCl3 (except
for C6F4)) d 82.9, 52.9, 32.0, 25.3, 23.4; 19F NMR
(282 MHz, CDCl3) d ꢁ146.0 to ꢁ145.9 (m, 4F), ꢁ156.9
to ꢁ156.8 (m, 4F); Anal. Calcd for C26H28F8N2O2: C,
56.52; H, 5.11; N, 5.07; Found: C, 56.91; H, 5.32; N,
4.71. HLPC analysis: hexane/i-PrOH/Et2NH (70:30:0.4),
0.5 mL minꢁ1, UV 254 nm, retention time (tR); (S,S)-3g:
21.4 min (>99%), (R,R)-3g: 39.4 min (0%).
tral SiO2, CH2Cl2/MeOH, 30:1) to give (S,S)-3d (8.10 mg,
32
0.0112 mmol) in 90% yield: yellow oil; ½aꢂD ¼ ꢁ41:9 (c
0.19, MeOH); IR (neat, NaCl plate, cmꢁ1) 3395, 3325,
3031, 2962, 1651, 1489, 1265, 1126, 988; 1H NMR
(300 MHz, CDCl3) d 7.28–7.42 (m, 20H), 6.35 (s, 2H),
4.31 (s, 2H), 1.94 (br, 4H); 13C NMR (75 MHz, CDCl3 (ex-
cept for C6F4)) d 139.4, 128.5, 127.0, 86.8, 52.5; 19F NMR
(282 MHz, CDCl3) d ꢁ145.9 to ꢁ145.8 (m, 4F), ꢁ155.1 to
ꢁ155.0 (m, 4F); Anal. Calcd for C40H28F8N2O2: C, 66.67;
H, 3.92; N, 3.89; Found: C, 66.87; H, 4.23; N, 3.79. HLPC
4.1.8.
(1S,2S)-1,2-Bis(2,3,5,6-tetrafluoro-4-(3,3,5,5-tetra-
analysis: hexane/i-PrOH/Et2NH (60:40:0.1), 0.5 mL minꢁ1
,
methylcyclohexyloxy)phenyl)ethane-1,2-diamine (S,S)-3h.
Compound (S,S)-3h was prepared from (S,S)-2 (19.6 mg,
0.0500 mmol), KOH (56.1 mg, 1.00 mmol), 3,3,5,5-tetra-
methylcyclohexanol (2.00 g, 12.8 mmol), and DMF
(0.40 mL) in 58% yield (19.4 mg, 0.0292 mmol) by the pro-
cedure described for (S,S)-3d at 50 °C for 24 h: yellow oil;
UV 254 nm, retention time (tR); (S,S)-3d: 14.8 min (>99%),
(R,R)-3d: 21.9 min (0%).
4.1.5.
(1S,2S)-1,2-Bis(4-neopentyloxy-2,3,5,6-tetrafluoro-
phenyl)ethane-1,2-diamine (S,S)-3e. Compound (S,S)-3e