L. Beaufort et al. / Tetrahedron 63 (2007) 7003–7008
7007
obtained as an orange oil according to the procedure
described above starting from 50 wt % solution of tricyclo-
pentylphosphine in toluene (4.35 g, 9.11 mmol) and a,a,a-
tris(azidomethyl)toluene (0.71 g, 2.76 mmol). Yield:
4.3.3. Synthesis of CH3–C(CH2–N]PCp3)3–Cu(OTf)2.
This complex was synthesized as described above starting
from a,a,a-tris(tricyclopentylphosphine-iminophosphorane)-
ethane (0.50 g, 0.60 mmol) and copper(II) triflate (0.18 g,
0.50 mmol). It was isolated as an apple green solid. Yield:
1
1.94 g (79%). H NMR (CD2Cl2): d¼1.60–2.48 (m, 81H,
1
cyclopentyl), 3.55 (d, 6H, CH2), 7.24 (t, 1H, para-CH phen-
yl), 7.35 (t, 2H, meta-CH phenyl), 7.76 (d, 2H, ortho-CH
phenyl) ppm. 13C NMR (CD2Cl2): d¼27.1 (C3 cyclopentyl),
28.2 (C2 cyclopentyl), 34.6 (C1 cyclopentyl), 37.8 (CH2),
38.4 (CH2), 47.8 (CH2), 50.0 (C), 127.8 (phenyl), 128.8
(phenyl), 130.2 (phenyl), 141.3 (phenyl) ppm. FTIR
(NaCl): n ¼ 3043, 2951, 2865, 1658, 1595, 1493, 1448,
1262, 1227, 1176, 1121, 1057, 1030, 906, 761, 729,
0.49 g (82%). H NMR (CD2Cl2): d¼1.07 (s, 3H, CH3),
1.73–2.51 (m, 81H, cyclopentyl), 3.02 (s, 6H, CH2) ppm.
13C NMR (CD2Cl2): d¼20.0 (s, CH3), 27.0 (C3 cyclo-
pentyl), 28.6 (C4 cyclopentyl), 34.9 (C5 cyclopentyl), 35.5
(C2 cyclopentyl), 37.9 (CH2), 38.6 (CH2), 41.6 (CH2)
ppm. 31P NMR (CD2Cl2): d¼53.0 ppm. FTIR (KBr):
n ¼ 2955, 2866, 1444, 1380, 1258, 1219, 1149, 1085,
1027, 906, 637, 515 cmꢀ1. Elemental analysis (%) calcd
for C52H90CuF6N3O6P3S2 (1073.90): C 52.58, H 7.64, N
3.54; found C 51.9, H 7.0, N 3.1.
697 cmꢀ1
.
4.3. Representative examples for the synthesis of metal
complexes
4.3.4. Synthesis of Ph–C(CH2–N]PPh3)3–CuBr. This
complex was synthesized as described above from a,a,a-
tris(triphenylphosphine-iminophosphorane)toluene (0.22 g,
0.23 mmol) and copper(I) bromide (0.03 g, 0.21 mmol). It
4.3.1. Synthesis of CH3–C(CH2–N]PCp3)3–NiBr2. A
solution of a,a,a-tris(tricyclopentylphosphine-iminophos-
phorane)ethane (0.512 g, 0.6 mmol) in dry CH2Cl2 (10 mL)
was added with a cannula under an inert atmosphere to a
suspension of dimethoxyethane nickel bromide complex
(0.16 g, 0.5 mmol) in dry CH2Cl2 (20 mL) and the reaction
mixture was stirred for 16 h at room temperature. The ini-
tially orange suspension turned brown and then to green.
The solvent was evaporated under vacuum and the remain-
ing blue-grey solid was washed with dry diethyl ether
(3ꢂ10 mL) and dried under vacuum. Yield: 0.5 g (94%).
1H NMR (CD2Cl2): d¼1.13 (s, 3H, CH3), 1.39–3.1 (m,
72H, CH2 cyclopentyl), 3.28 (s, 9H, CH cyclopentyl), 4.00
(s, 6H, CH2) ppm. 13C NMR (CD2Cl2): d¼17.8 (CH3),
27.2 (C3 and C4 cyclopentyl), 28.5 (C2 and C5 cyclopentyl),
30.2 (CH2), 33.1 (CH2), 34.5 (CH2), 38.4 (d, C1 cyclopentyl)
ppm. 31P NMR (CD2Cl2): d¼64.9 ppm. FTIR (KBr):
n ¼ 3090, 2949, 2866, 1623, 1450, 1380, 1296, 1258,
1091, 1002, 944, 912, 598, 521 cmꢀ1. Elemental analysis
(%) calcd for C50H90Br2N3NiP3 (1044.70): C 57.42, H
8.68, N 4.02; found C 56.4, H 8.4, N 3.8.
1
was isolated as a yellow solid. Yield: 0.19 g (80%). H
NMR (CD2Cl2): d¼1.68 (s, 2H, CH2), 1.91 (s, 2H, CH2),
2.05 (s, 2H, CH2), 7.46–7.65 (m, 50H, aromatic) ppm. 13C
NMR (CD2Cl2): d¼24.1 (CH2), 27.38 (CH2), 33.1 (CH2),
126.0 (C4 phenyl), 129.5 (C3 and C5 phosphine), 130.8
(C3 and C5 phenyl), 132.8 (C2 and C6 phosphine), 133.4
(C2 and C6 phenyl), 134.4 (C4 phosphine), 136.1 (C1 phos-
phine) ppm. FTIR (KBr): n ¼ 3051, 2956, 2920, 2847, 1674,
1588, 1481, 1436, 1259, 1182, 1108, 1027, 997, 919, 803,
747, 720, 694, 542, 523 cmꢀ1. Elemental analysis (%) calcd
for C64H56BrCuN3P3 (1103.54): C 69.66, H 5.11, N 3.81;
found C 69.0, H 4.8, N 3.81.
4.3.5. Synthesis of CH3–C(CH2–N]PPh3)3–CuBr. This
compound was synthesized as described above from a,a,a-
tris(triphenylphosphine-iminophosphorane)ethane (0.3 g,
0.33 mmol) and copper(I) bromide (0.04 g, 0.28 mmol).
It was isolated as a paramagnetic green solid. Yield: 0.29 g
1
(92%). H NMR (CD2Cl2): d¼0.95 (s, 3H, CH3), 2.55–
3.11 (broad m, 6H, CH2), 7.48–7.67 (m, 45H, phenyl)
ppm. 31P NMR (CD2Cl2): d¼27.0 ppm. FTIR (KBr):
n ¼ 3050, 2963, 2810, 1587, 1481, 1435, 1306, 1259,
1179, 1108, 1027, 997, 932, 862, 801, 747, 713, 693, 553,
522 cmꢀ1. Elemental analysis (%) calcd for C59H54
BrCuN3P3 (1041.47): C 68.04, H 5.23, N 4.03; found
C 67.5, H 4.8, N 4.4.
4.3.2. Synthesis of Ph–C(CH2–N]PCp3)3–Cu(OTf)2. A
solution of a,a,a-tris(tricyclopentylphosphine-iminophos-
phorane)toluene (0.422 g, 0.56 mmol) in dry CH2Cl2
(15 mL) was added to a solution of copper(II) triflate
(0.143 g, 0.47 mmol) in dry CH2Cl2 (10 mL). The solution
became green instantaneously. The reaction mixture was
stirred for 18 h at room temperature, during that period of
time the copper salt had completely disappeared. The sol-
vent was evaporated under vacuum and the resulting solid
was washed with diethyl ether (5ꢂ10 mL) and dried under
vacuum to afford a light green powder. Yield: 0.41 g
(83%). 1H NMR (CD2Cl2): d¼1.65–1.91 (m, 72H, CH2
cyclopentyl), 2.39 (s, 9H, CH cyclopentyl), 3.50 (s, 6H,
CH2), 7.36–7.52 (m, 5H, CH phenyl) ppm. 13C NMR
(CD2Cl2): d¼27.2 (C3 cyclopentyl), 28.6 (C4 cyclopentyl),
35.1 (C2 cyclopentyl), 35.7 (C5 cyclopentyl), 37.9 (CH2),
38.6 (CH2), 48.6 (CH2), 52.76 (C1 cyclopentyl), 123.5 (C5
aromatic), 128.5 (C2 aromatic), 129.2 (C3 aromatic),
129.5 (C3 aromatic), 142.1 (C1 aromatic) ppm. FTIR
(KBr): n ¼ 3056, 2959, 2871, 1451, 1384, 1260, 1222,
1151, 1099, 1030, 911, 703, 637, 572, 516 cmꢀ1. Elemental
analysis (%) calcd for C57H92CuF6N3O6P3S2 (1249.96): C
54.77, H 7.42, N 3.36; found C 53.9, H 6.9, N 3.0.
Acknowledgements
One of us (L.B.) thanks BP-Solvay for a research grant.
References and notes
1. Britovsek, G. J. P.; Gibson, V. C.; Wass, D. F. Angew. Chem.,
Int. Ed. 1999, 38, 428–447.
2. Ittel, S. D.; Johnson, L. K.; Brookhart, M. Chem. Rev. 2000,
100, 1169–1203.
3. Mecking, S. Angew. Chem., Int. Ed. 2001, 40, 534–540.
4. Gibson, V. C.; Spitzmesser, S. K. Chem. Rev. 2003, 103,
283–315.
5. Domski, G. J.; Rose, J. M.; Coates, G. W.; Bolig, A. D.;
Brookhart, M. Prog. Polym. Sci. 2007, 32, 30–92.