6730 Organometallics, Vol. 28, No. 23, 2009
Oguadinma and Schaper
meta Bn), 126.4 (para Bn), 95.1 (HC(CdN)2), 50.7 (Bn CH2),
19.6 (Me(CdN)2). Anal. Calcd for C19H22N2: C, 81.97; H, 7.96;
N, 10.06. Found: C, 81.55; H, 8.12; N, 10.10.
(s, 6H, Me(CdN)2). 13C NMR (C6D6, 101 MHz): δ 165.0
(CdN), 143.5 (ipso Bn), 139.4 (ipso C(H)Ph), 128.8, 128.7,
126.6, 126.4, 125.7, 96.6 (HC(CdN)2), 85.0 (C(H)Ph) 56.2 (Bn
CH2), 21.7 (Me(CdN)2). Anal. Calcd for C33H33N2Cu: C,
76.05; H, 6.30; N, 5.37. Found: C, 75.90; H, 6.45; N, 5.32.
{(nacnacBn)Cu}2(μ-PhCCPh), 6. Diphenylacetylene (DPA)
(64 mg, 0.36 mmol) and 1 (100 mg, 0.36 mmol) were dissolved
in ether (2 mL). CuOtBu (49 mg, 0.36 mmol) was dissolved in
ether (4 mL) to give a yellow solution and added to the original
solution. After stirring for 15 min, a yellow precipitate formed.
The mixture was filtered and the residue washed with hexane (2
mL). Residual solvent was removed on the vacuum line to afford
a yellow powder (65 mg, 42%). 1H NMR (C6D6, 400 MHz, 298
K): δ 7.21-6.70 (m, 30H, CPh and Bn), 4.67 (s, 2H, HC-
(CdN)2), 4.66 (bs, 8H, Bn CH2), 1.62 (s, 12H, Me(CdN)2).
13C NMR (C6D6, 101 MHz, 298 K): δ 165.9 (CdN), 144.1 (ipso
Bn), 131.2, 128.9, 128.4 (ortho or meta Bn), 127.9, 127.2 126.7,
126.1, 101.3 (PhCCPh), 98.9 (HC(CdN)2), 58.8 (Bn CH2), 21.7
(Me(CdN)2). Anal. Calcd for C52H52N4Cu2: C, 72.62; H, 6.09;
N, 6.51. Found: C, 71.70; H, 6.30; N, 6.45. Crystals suitable for
X-ray diffraction studies were obtained from a 1:1 toluene/
hexane solution upon cooling to -35 °C.
(nacnacBn)Cu(styrene), 2. To a mixture of 1 (250 mg, 0.90
mmol), CuOtBu (120 mg, 0.88 mmol), and styrene (200 mg, 1.80
mmol) was added toluene (5 mL) to afford a yellow solution.
After stirring for 1 h, the solution was reduced to one-eighth of
its volume and layered with 2 mL of hexane. A colorless powder
formed after 1 day (250 mg, 63%). 1H NMR (C6D6, 400 MHz,
298 K): δ 6.93-7.19 (m, 15H, Bn and styrene), 4.75-4.52 (m,
6H, CH2Ph, HC(CdN)2 and PhHCd), 3.45 (d, J = 14 Hz, 1H,
cis H2Cd), 3.19 (d, J = 9 Hz, 1H, trans H2Cd), 1.64 (s, 6H,
Me(CdN)). 13C NMR (C6D6, 101 MHz, 298 K): δ 165.1 (CdN),
143.3 (ipso Bn), 140.1 (ipso styrene) 128.7 (ortho styrene), 128.6
(meta or ortho Bn), 126.6 (para styrene), 126.5 (meta or ortho
Bn), 126.3 (meta styrene), 125.6 (para Bn), 96.6 (HC(CdN)2),
89.1 (1JCH = 172 Hz, PhHCd), 67.1 (1JCH = 161 Hz, H2Cd),
57.3 (Bn CH2), 21.8 (Me(CdN)). Anal. Calcd for C27H29N2Cu:
C, 72.86; H, 6.57; N, 6.29. Found: C, 72.84; H, 6.60; N, 6.39.
Crystals suitable for X-ray were obtained from toluene solution
in the presence of excess styrene at -35 °C.
(nacnacBn)Cu(H2CdCHCN), 3. CuOtBu (137 mg, 1.0 mmol),
1 (300 mg, 1.1 mmol), and acrylonitrile (1.0 g, 19 mmol) were
dissolved in toluene (5 mL) to give a yellow solution. After
stirring for 15 min, the solution was evaporated to give yellow-
brown oil. Hexane (6 mL) was added, and the resulting suspen-
sion was kept at -35 °C for 1 day. The supernatant was decanted
and residual solvent removed on the vacuum line to afford a
yellow powder (115 mg, 29%). 1H NMR (C6D6, 400 MHz, 298
K): δ 7.01-7.11 (m, 10H, Bn), 4.72 (s, 1H, HC(CdN)2), 4.61 (bs,
4H, Bn), 2.72-2.86 (m, 2H, dCHCN and cis H2Cd), 2.39 (d,
J = 9 Hz, 1H, trans H2Cd), 1.79 (s, 6H, Me(CdN)2). 13C NMR
(C6D6, 101 MHz, 298 K): δ 165.1 (CdN), 142.5 (ipso Bn), 128.8
(ortho or meta Bn), 126.7, 126.4, 105.4 (dCHCN), 96.9
(HC(CdN)2), 70.6 (H2Cd), 58.0 (dCHCN), 54.0 (Bn CH2),
21.7 (Me(CdN)2). IR (toluene): νCN = 2225 cm-1. Anal. Calcd
for C22H24N3Cu: C, 67.07; H, 6.14; N, 10.66. Found: C, 66.25;
H, 6.09; N, 10.14. Crystals obtained by layering a concentrated
toluene solution with hexane at -35 °C were too small for X-ray
diffraction studies. Good quality crystals were obtained, if two
drops of DMSO were added to the toluene solution before
layering with hexane at -35 °C for 24 h.
(nacnacBn)Cu(PhCCPh), 6b. In the presence of excess (>10
equiv) diphenylacetylene in C6D6 at room temperature, 6 con-
verts completely into the monometallic complex 6b. H NMR
1
(C6D6, 400 MHz, 298 K): δ 7.26-6.80 (m, 20H, CPh and Bn),
4.83 (s, 1H, HC(CdN)2), 4.54 (bs, 4H, Bn CH2), 1.85 (s, 6H,
Me(CdN)2). 13C NMR (C6D6, 101 MHz, 298 K): δ 165.3
(CdN), 142.7 (ipso Bn), 129.0 (ortho or meta Bn), 128.6,
126.9, 126.6 (ortho or meta Bn), 126.2, 125.8, 103.9 (PhCCPh),
96.7 (HC(CdN)2), 56.7 (Bn CH2), 21.8 (Me(CdN)2). One
resonance missing.
(nacnacBn)CuPPh3, 7. CuOtBu (244 mg, 1.80 mmol), 1 (500
mg, 1.80 mmol), and PPh3 (477 mg, 1.82 mmol) were dissolved in
toluene (5 mL) to give a yellow solution, which became brown
within 5 min. After stirring for 1 h, the solvent was evaporated to
yield a viscous, gummy residue. Washing twice with 30 mL of
hexanes yielded a white solid (760 mg, 70%). After 1 day,
additional colorless crystals were obtained from the hexane
1
wash. H NMR (C6D6 400 MHz): δ 7.22-6.86 (m, 25H, PPh3
and Bn), 4.97 (s, 1H, HC(CdN)2), 4.93 (s, 4H, Bn CH2), 2.01 (s,
6H, Me(CdN)2). 13C NMR (C6D6, 101 MHz): δ 165.4 (CdN),
144.0 (ipso Bn), 134.6 (d, J = 6 Hz, ipso PPh3), 133.8 (d, J =
4 Hz, ortho or meta PPh3), 129.5, 128.7 (d, J = 4 Hz ortho or
meta PPh3), 126.8, 125.9, 96.7 (HC(CdN)2), 58.9 (Bn CH2), 21.9
(Me(CdN)2) (one peak missing). 31P NMR (C6D6, 101 MHz): δ
3.5. Anal. Calcd for C37H36N2PCu: C, 73.67; H, 6.02; N, 4.69.
Found: C, 73.82; H, 6.52; N, 4.91.
(NacnacBn)Cu(H2CdCHCH2OPh), 4. CuOtBu (137 mg, 1.0
mmol), 1 (300 mg, 1.1 mmol), and allyl phenyl ether (86 mg, 1.0
mmol) were dissolved in toluene (5 mL) to give a yellow solution.
After stirring for 15 min, hexane (5 mL) was added. The
resulting suspension was kept at -35 °C for 1 day. The super-
natant was decanted and residual solvent removed on the
vacuum line to afford a yellow powder (300 mg, 59%). 1H
NMR (C6D6, 400 MHz, 298 K): δ 6.54-7.17 (m, 15H, Bn and
OPh), 4.68-4.79 (m, 5H, Bn CH2 and HC(CdN)2), 4.00 (m, 1H,
PhOCH2(H)Cd), 3.79 (dd, J = 3 Hz, 11 Hz, 1H, PhOCH2-),
3.49 (dd, J = 3 Hz, 11 Hz, 1H, PhOCH2-), 3.29 (d, J = 14 Hz,
1H, cis H2Cd), 3.16 (d, J = 9 Hz, 1H, trans H2Cd), 1.87 (s, 6H,
Me(CdN)2). 13C NMR (C6D6, 101 MHz, 298 K): δ 165.3
(CdN), 159.1 (ipso OPh), 143.0 (ipso Bn), 129.5 (ortho or meta
OPh) 128.7 (ortho, or meta Bn), 126.4 (meta or ortho Bn), 120.8
(para, OPh), 114.9 (para Bn), 96.7 (HC(CdN)2), 84.8
(-OCH2CHd), 71.7 (H2Cd), 68.2 (-OCH2CHd), 58.2 (Bn
CH2), 21.8 (Me(CdN)2). One peak (ortho or meta OPh) missing.
Anal. Calcd for C28H31N2OCu: C, 70.78; H, 6.58; N, 5.90.
Found: C, 70.36; H, 6.72; N, 5.92.
(nacnacBn)CuCN(C6Me2H3), 8. A yellow solution of CuOtBu
(80 mg, 0.60 mmol) in toluene (2 mL) was added to a flask
containing 1 (155 mg, 0.55 mmol) and xylyl isocyanide (72 mg,
0.55 mmol). The resulting yellow solution was layered with
hexane (4 mL) and kept at -35 °C. Yellow crystals formed after
1 day (145 mg, 53%). 1H NMR (C6D6, 400 MHz): δ 7.40 (d, J =
8 Hz, 4H, ortho Bn), 7.12 (m, 4H, meta Bn), 6.97 (t, J = 8 Hz,
2H, para Bn), 6.69 (t, J = 8 Hz, 1H, CNArMe2), 6.52 (d, J = 8
Hz, 2H, CNArMe2), 5.00 (s, 4H, Bn CH2), 4.82 (s, 1H, HC-
(CdN)2), 2.02 (s, 6H, Me(CdN)2), 1.75 (s, 6H, CNArMe2). 13
C
NMR (C6D6 101 MHz): δ 164.6 (CdN), 144.4 (ipso Bn), 134.3,
128.3, 127.9, 127.8, 127.6, 126.2, 96.0 (HC(CdN)2), 59.2, 21.9
(Me(CdN)2), 18.5 (CNArMe2). Anal. Calcd for C30H30N3Cu:
C, 71.23; H, 6.40; N, 8.90. Found: C, 70.96; H, 6.04; N, 8.90. IR
(nacnacBn)Cu(trans-stilbene), 5. To a mixture of 1 (200 mg,
0.72 mmol), CuOtBu (100 mg, 0.73 mmol), and trans-stilbene
(130 mg, 0.72 mmol) was added toluene (4 mL) to afford a
yellow solution. After stirring for 15 min, the solution was
layered with hexane (4 mL) and kept at -35 °C. Yellow crystals
formed after 6 h (189 mg, 50%). 1H NMR (C6D6, 400 MHz, 298
K): δ 7.00-7.28 (m, 20H, Bn and C(H)Ph), 4.92 (s, 2H, Ph-
(H)Cd), 4.65 (s, 1H, HC(CdN)2), 4.59 (bs, 4H, Bn CH2), 1.70
(toluene): νCN = 2114 cm-1
.
General Experimental Procedure for the Exchange Experi-
ments. Complex 2 (10 mg, 11 μmol) was dissolved in C6D6
(700 μL), and the olefin (0.5 equiv) was added. The solution was
transferred to a J. Young tube for 1H NMR analysis. The
procedure was repeated with 1 and 2 equiv of olefin. For stilbene
and diphenylacetylene peak overlap prevented the determina-
tion of the free olefin concentration directly from the NMR