[C6H5CH2NH]ϩ, 91 [C6H5CH2]ϩ. HRMS: calculated for
C28H40N2PCl [M]ϩ = 471.250991; found [M]ϩ = 471.251976. 1H-
NMR (CDCl3): 7.30 (m, 8H, C6H and C7H), 4.28 (m, 4H, C4H),
2.95 (m, 2H, C3H), 1.95 (m, 2H, C2Heq), 1.72 (m, 2H, C1Heq),
1.32 (s, 18H, C10H), 1.23 (m, 2H, C1Hax), 0.88 (m, 2H, C2Hax).
29.8 (s, 2C, C2), 24.0 (s, 2C, C1). 31P{1H}-NMR (CDCl3):
178.0.
(1R,2R)-N,NЈ-Bis(2,6-difluorobenzylidene)-1,2-diaminocyclo-
hexane (2c). In a 250 cm3, three-necked flask equipped with
magnetic stirrer, thermometer, condenser and 50 cm3 adding
funnel, anhydrous potassium carbonate (5.23 g, 0.038 mol) and
the tartrate salt of 1 (5.00 g, 0.019 mol) were dissolved in
distilled water (40 cm3). Ethanol (160 cm3) was added and
the resulting white slurry was heated to reflux. A solution of
2,6-difluorobenzaldehyde (5.4 g, 4.1 cm3, 0.038 mol) in ethanol
(40 cm3) was added over 30 min. After refluxing for 4 h, the
mixture was allowed to cool to room temperature, distilled
water (40 cm3) added and the flask cooled to 5 ЊC and allowed
to stand overnight. The solvents were removed under reduced
pressure to give a viscous yellow solid, which was dissolved in
dichloromethane (50 cm3). The organic layer was washed with
distilled water (3 × 20 cm3) and saturated brine (20 cm3), and
dried over magnesium sulfate. Dichloromethane was removed
to afford a yellow oil which crystallised from pentane at Ϫ35 ЊC
to give pale yellow crystals. Yield: 6.0 g, 90%. M.p.: 94–96 ЊC.
Found C: 66.5, H: 5.0, N: 7.6; C20H18N2F2 requires C: 66.3,
13C{1H}-NMR (CDCl3): 150.3 (s, 2C, C8), 135.1 (d, 2C, 3JP–C
=
6.5 Hz, C5), 128.6 (s, 4C, C6), 125.4 (s, 4C, C7), 67.9 (m, 2C, C3),
48.6 (m, 2C, C4), 34.1 (s, 2C, C9), 31.4 (s, 6C, C10), 29.5 (s, 2C,
C2), 24.3 (s, 2C, C1). 31P{1H}-NMR (CDCl3): 183.0.
(1R,2R)-N,NЈ-Bis(4-cyanobenzylidene)-1,2-diaminocyclo-
hexane (2b). The same procedure used to prepare 2a was
employed with K2CO3 (7.88 g, 0.057 mol), 1 (7.49 g, 0.028 mol)
and 4-cyanobenzaldehyde (10.54 g, 0.057 mol), 8 h reflux.
Yield: 8.4 g, 88% (white crystals). M.p.: 139–141 ЊC. νmax/cmϪ1
:
᎐
2224 (aryl-C᎐N), 1643 (C᎐N), 1593 (C᎐C), 843 and 832 (C–H,
᎐
᎐
᎐
1,4-disubstituted benzene ring). m/z (EI): 341 [M ϩ H]ϩ, 340
[M]ϩ, 204 [NH3C6H10NHCH2C6H4]ϩ, 131 [CNC6H4CH2NH]ϩ.
HRMS: calculated for C22H20N4 [M]ϩ = 340.168797; found
1
[M]ϩ = 340.165693 (within 9.1 ppm). H-NMR (CDCl3): 8.28
3
(s, 2H, C4H), 7.69 (d, 4H, JC H–C H = 8.3 Hz, C6H), 7.60 (d,
6
7
4H, JC H–C H = 8.2 Hz, C7H), 3.45 (m, 2H, C3H), 1.82 (m,
6H, C2H and C1Heq), 1.50 (m, 2H, C1Hax). 13C{1H}-NMR
(CDCl3): 159.0 (s, 2C, C4), 140.0 (s, 2C, C5), 132.3 (s, 4C, C7),
128.3 (s, 4C, C6), 118.4 (s, 2C, C9), 106.8 (s, 2C, C8), 73.9 (s, 2C,
C3), 32.6 (s, 2C, C2), 24.2 (s, 2C, C1).
3
6
7
H: 5.0, N: 7.7%. νmax/cmϪ1: 3040 (aryl-H), 1640 (C᎐N), 1587
᎐
(C᎐C), 1462 and 680 (C–F), 783 (C–H, 1,2,3-trisubstituted ben-
᎐
zene ring). m/z (ES): 385 [M ϩ Na]ϩ, 363 [M ϩ H]ϩ. 1H-NMR
(CDCl3): 8.39 (s, 2H, C4H), 7.23 (m, 2H, C8H), 6.84 (m, 4H,
C7H), 3.46 (m, 2H, C3H), 1.87 (m, 4H, C2H), 1.77 (m, 2H,
C1Heq), 1.36 (m, 2H, C1Hax). 13C{1H}-NMR (CDCl3): 161.6
(1R,2R)-N,NЈ-Bis(4-cyanobenzyl)-1,2-diaminocyclohexane
(3b). Compound 2b (4.00 g, 0.012 mol) was dissolved in
methanol under a dinitrogen blanket (100 cm3) and sodium
borohydride (1.34 g, 0.035 mol) was added in small portions
at room temperature. The mixture was heated under reflux for
6 h, followed by cooling to room temperature. Distilled water
(80 cm3) was added, which resulted in the decolouration of
the solution. The solution was then heated to boiling point for
20 min and extracted with dichloromethane (3 × 80 cm3). The
combined organic layers were dried over magnesium sulfate.
The solution was filtered and the volatiles removed to give 3b as
a pale yellow oil. The product was recrystallised from pentane
in air to give white crystals. Yield: 2.0 g, 49%. M.p.: 73–75 ЊC.
Found C: 76.2, H: 7.1, N: 16.1;C22H24N4 requires C: 76.7, H:
7.0, N: 16.3%. νmax/cmϪ1: 3254 (N–H stretching), 3066 (aryl-H),
1
3
(dd, 4C, JC–F = 255.7, JC–F = 6.9 Hz, C6), 151.6 (s, 2C, C4),
130.9 (t, 2C, 3JC–F = 10.6 Hz, C8), 114.1 (t, 2C, 2JC–F = 14.2 Hz,
C5), 111.6 (dd, 4C, 2JC–F = 23.5, 4JC–F = 2.0 Hz, C7), 75.3 (s, 2C,
C3), 32.6 (s, 2C, C2), 24.3 (s, 2C, C1). 19F-NMR (CDCl3): Ϫ114.1
(m, 4F, C6F).
(1R,2R)-N,NЈ-Bis(2,6-difluorobenzyl)-1,2-diaminocyclo-
hexane (3c). The same procedure used to prepare 3b was
employed with 2c (2.00 g, 0.006 mol) and NaBH4 (0.63 g, 0.017
mol), 3 h reflux. Yield: 1.7 g, 84% (yellow liquid). Found C:
65.3, H: 6.1, N: 7.6; C20H22N2F4 requires C: 65.6, H: 6.1, N:
7.7%. νmax/cmϪ1: 3308 (N–H stretching), 3030 (aryl-H), 2930
and 2857 (CH ), 1592 (C᎐C, aromatic rings), 1467 (C–F),
᎐
2
782 (C–H, 1,2,3-trisubstituted benzene ring). m/z (EI): 366
[M]ϩ, 222 [C6H8NHCH2C6H3F2]ϩ, 142 [F2C6H3CH2NH]ϩ, 127
[F2C6H3CH2]ϩ. 1H-NMR (CDCl3): 7.17 (m, 2H, C8H), 6.83
(m, 4H, C7H), 3.91 (d, 2H, 2JH–H = 12.8 Hz, C4H), 3.77 (d, 2H,
2JH–H = 13.0 Hz, C4H), 2.14 (m, 4H, C3H and C2Heq), 1.90
(s, 2H, NH), 1.72 (m, 2H, C1Heq), 1.25 (m, 2H, C1Hax), 1.03
᎐
2227 (aryl-C᎐N), 850–812 (C–H, 1,4-trisubstituted benzene
᎐
ring). m/z (EI): 344 [M]ϩ, 228 [M Ϫ NCC6H4CH2]ϩ, 211
[NCC6H4CH2NHC6H10]ϩ, 133 [NCC6H4CH2NH3]ϩ, 116
[NCC6H4CH2]ϩ, 96 [C6H10N]ϩ. 1H-NMR (CDCl3): 7.57 (d, 4H,
3
3
JC H–C = 8.1 Hz, C7H), 7.41 (d, 4H, JC H–C H = 8.0 Hz,
6
7
6
7
C6H), 3.82 (d, 2H, JH–H = 14.1 Hz, C4H), 3.71 (d, 2H, JH–H
=
(m, 2H, C2Hax). 13C{1H}-NMR (CDCl3): 161.8 (dd, 4C, 1JC–F
=
3 3
2
2
14.5 Hz, C4H), 2.22 (m, 2H, C3H), 2.08 (m, 2H, C2Heq), 1.96
(s, 2H, NH), 1.70 (m, 2H, C1Heq), 1.24 (m, 2H, C1Hax), 1.02
(m, 2H, C2Hax). 13C{1H}-NMR (CDCl3): 146.8 (s, 2C, C5),
132.1 (s, 4C, C7), 128.6 (s, 4C, C6), 118.9 (s, 2C, C9), 110.6
(s, 2C, C8), 61.1 (s, 2C, C3), 50.5 (s, 2C, C4), 31.5 (s, 2C, C2), 24.9
(s, 2C, C1).
247.7, JC–F = 9.0 Hz, C6), 128.5 (t, 2C, JC–F = 10.5 Hz, C8),
116.6 (t, 2C, 2JC–F = 20.6 Hz, C5), 111.1 (d, 4C, 2JC–F = 25.7 Hz,
C7), 60.7 (s, 2C, C3), 37.9 (s, 2C, C4), 31.5 (s, 2C, C2), 25.0 (s, 2C,
C1). 19F-NMR (CDCl3): Ϫ116.7 (broad t, 4F, J = 5.7 Hz, C6F).
(3R,8R)-1-Chloro-2,9-bis(2,6-difluorobenzyl)-2,9-diaza-1-
phosphabicyclo[4.0.3]nonane (4c). The same procedure used to
prepare 4b was employed with PCl3 (0.12 cm3, 0.19 g, 0.0014
mol), N-methylmorpholine (0.45 cm3, 0.41 g, 0.0041 mol) and
3c (0.5 g, 0.0014 mol) in pentane. Yield: 0.5 g, 85% (pale yellow
liquid). Found C: 55.3, H: 4.9, N: 6.3, Cl: 8.0, P: 7.3; C20H20-
N2ClF4P requires C: 55.8, H: 4.7, N: 6.5, Cl: 8.2, P: 7.2%. m/z
(3R,8R)-1-Chloro-2,9-bis(4-cyanobenzyl)-2,9-diaza-1-
phosphabicyclo[4.0.3]nonane (4b). The same procedure used to
prepare 4a was employed with PCl3 (0.13 cm3, 0.20 g, 0.0015
mol), triethylamine (0.61 cm3, 0.44 g, 0.0044 mol) and 3b (0.5 g,
0.0015 mol) in a mixture of dry pentane and toluene. Recrystal-
lisation from pentane over several weeks at Ϫ35 ЊC afforded
crystals suitable for single crystal X-ray analysis. Yield: 0.6 g,
98%. HRMS: calculated for C28H40N2PCl [M]ϩ = 471.250991;
found [M]ϩ = 471.251976. 1H-NMR (CDCl3): 7.64 (d, 2H,
1
(EI): 430 [M]ϩ, 395 [M Ϫ Cl]ϩ, 127 [F2C6H3CH2]ϩ. H-NMR
(CDCl3): 7.24 (m, 2H, C8H), 6.88 (m, 4H, C7H), 4.44 (m, 1H,
C4H), 4.31 (m, 2H, C4H), 4.02 (m, 1H, C4H), 3.13 (m, 1H, C3H),
2.67 (m, 1H, C3H), 2.67 (m, 2H, C2Heq), 2.20 (m, 2H, C1Heq),
3
3
JC H–C H = 8.3 Hz, C7H), 7.48 (d, 4H, JC H–C H = 13.1 Hz,
1.31 (m, 2H, C1Hax), 1.14 (m, 2H, C2Hax). 1H{31P}-NMR
6
7
6
7
C6H), 4.42 (m, 2H, C4H), 4.15 (m, 2H, C4H), 3.09 (m, 2H, C3H),
1.76 (m, 4H, C2Heq and C1Heq), 1.14 (m, 4H, C1Hax and C2Hax).
13C{1H}-NMR (CDCl3): 144.1 (d, 2C C5), 132.4 (s, 4C, C7),
128.7 (s broad, 4C, C6), 118.7 (s, 2C, C9), 111.5 (s, 2C, C8), 68.1
(CDCl3): as above, except 4.44 (d, 1H, JC H –C H = 14.6 Hz,
2
4
4
a
b
C4Ha), 4.32 (d, 1H, JC H –C H = 14.8 Hz, C4Hb), 4.28 (d, 1H,
2
4
4
a
b
2
2
JC H –C H = 14.3 Hz, C4Ha), 4.02 (d, 1H, JC H –C H = 14.1 Hz,
4
4
4
4
a
b
a
b
3
3
C4Hb), 3.14 (td, 1H, JC H–C H = 8.7, JC H –C H = 2.2 Hz,
3
4
3
3
a
b
(d, 2C, JP–C = 8.6 Hz, C3), 49.1 (d, 2C, JP–C = 21.8 Hz, C4),
C3Ha), 2.67 (td, 1H, JC H–C H = 8.7, JC H –C H = 2.2 Hz,
2
2
3
3
3
4
3
3
a
b
2930
J. Chem. Soc., Dalton Trans., 2002, 2921–2932