Organometallics
Article
For the IPr-supported complexes, the following numbering scheme
describes the protons on the IPr ligand:
146.58, 136.77, 130.07, 124.16, 124.06, 124.02, 54.19, 50.83, 38.33,
28.86, 28.83, 26.48, 26.24, 23.16, 23.04.
(η3-2-cyanoallyl)Pd(IPr)Cl (I-CN). (μ-Cl)2Pd2(IPr)2Cl2 (172.6 mg,
0.305 mmol), K2CO3 (420 mg, 3 mmol), and α-(chloromethyl)-
acrylonitrile (93 mg, 0.92 mmol) were dissolved in a biphasic mixture
of 10 mL of CH2Cl2 and 10 mL of H2O in a round-bottom flask.
The flask was sealed with a rubber septum, and CO was bubbled
through the reaction mixture for 15 min while it was stirred at room
temperature. The reaction mixture was stirred at room temperature for
an additional 15 min under a static atmosphere of CO. The CH2Cl2
layer was isolated using a separatory funnel and dried with MgSO4.
The volatiles were removed under reduced pressure, and the resultant
residue was purified through column chromatography using a 1/1
pentane/diethyl ether solvent mixture to yield I-CN (123 mg, 68%) as
a pale yellow solid. The crude product was loaded onto the column by
adhering it to ∼0.4 g of silica gel and loading this silica gel on top of
the column. Anal. Calcd for C31H40ClN3Pd: C, 62.41; H, 6.76; N, 7.04.
Found: C, 62.58; H, 6.71; N, 7.03.
(η3-2-phenylallyl)Pd(IPr)Cl (I-Ph). (2-phenylallyl)2Pd2(μ-Cl)2
(84.6 mg, 0.163 mmol) was suspended in diethyl ether (5 mL).
A solution of IPr (127 mg, 0.327 mmol) in diethyl ether (10 mL) was
added to the suspension of (2-phenylallyl)2Pd2(μ-Cl)2 using a cannula.
The reaction mixture was stirred at room temperature for 1 h.
The resultant diethyl ether solution was filtered through a silica gel
plug, and the volatiles were removed under reduced pressure to yield
I-Ph (162 mg, 76%) as a pale yellow powder. Anal. Calcd for
C36H45ClN2Pd: C, 66.76; H, 7.00; N, 4.33. Found: C, 66.59; H, 6.96;
N, 4.29.
1H NMR (400 MHz, C6D6): 7.23 (t, J = 7.7 Hz, 2H, H1), 7.13 (t,
J = 7.7 Hz, 4H, H2), 6.61 (s, 2H, H3), 3.85 (s, 1H, allyl-end), 3.25−
2.97 (br, 5H, H4 and allyl-end), 2.51 (d, J = 1.7 Hz, 1H, allyl-end),
1.57−1.29 (br, 13H, H5 and allyl-end), 1.00 (d, J = 6.9 Hz, 12H, H5).
13C{1H} NMR (101 MHz, C6D6): 183.59, 146.19, 135.99, 130.65,
124.58, 124.37, 115.19, 98.91, 74.56, 51.22, 28.89, 26.35, 22.99.
(μ-2-methylallyl)(μ-Cl)Pd2(IPr)2 (II-Me). (η3-2-MeC3H4)Pd(IPr)Cl
(I-Me; 52.3 mg, 0.089 mmol) and K2CO3 (19 mg, 1.5 equiv) were
transferred to a Schlenk flask and placed under dinitrogen. Degassed
ethanol (5 mL) was transferred by cannula into the Schlenk flask at
room temperature, and the reaction mixture was stirred at 40 °C for
3 h. The volatiles were removed under reduced pressure. The residue
was dissolved in 3/1 pentane/toluene and filtered through a silica
gel plug. The volatiles were then removed under reduced pressure to
give II-Me (37.7 mg, 78%) as a yellow solid. Anal. Calcd for
C58H79ClN4Pd2: C, 64.47; H, 7.37; N, 5.18. Found: C, 64.72; H, 7.63;
N, 5.19.
1H NMR (300 MHz, CDCl3): δ 7.37 (t, J = 7.8 Hz, 2H, H1), 7.21−
7.14 (m, 5H, H2 and 2Ph-p-H), 7.14 (s, 2H, H3), 7.04 (t, J = 7.6 Hz,
2H, 2Ph-m-H), 6.84 (d, J = 7.1 Hz, 2H, 2Ph-o-H), 4.06 (d, J = 2.9 Hz,
1H, allyl-end), 3.15 (d, J = 1.9 Hz, 1H, allyl-end), 3.11−2.99 (m, 3H,
H4 and allyl-end), 2.89 (septet, J = 6.7 Hz, 2H, H4), 1.94 (d, J = 2.5,
1H, allyl-end), 1.28 (d, J = 6.7, 6H, H5), 1.22 (d, J = 6.8, 6H, H5),
1.11 (d, J = 6.9, 6H, H5), 1.07 (d, J = 6.9, 6H, H5). 13C{1H} NMR
(125.8 MHz, CDCl3): δ 186.43, 146.01, 145.99, 138.45, 136.11,
130.52, 129.91, 128.15, 128.06, 127.06, 124.33, 123.92, 123.82, 71.39,
47.05, 28.64, 28.52, 26.48, 26.08, 22.75, 22.64.
(η3-2-tert-butylallyl)Pd(IPr)Cl (I-tBu). (2-tert-butylallyl)2Pd2(μ-Cl)2
(143 mg, 0.30 mmol) was suspended in diethyl ether (5 mL).
A solution of IPr (232 mg, 0.60 mmol in diethyl ether (15 mL) was
added to a suspension of (2-tert-butylallyl)2Pd2(μ-Cl)2 using a cannula.
The reaction mixture was stirred at room temperature for 1 h.
The resultant diethyl ether solution was filtered through a silica gel
plug, and the volatiles were removed under reduced pressure to yield
I-tBu (294 mg, 79%) as a pale yellow powder. Anal. Calcd for
C34H49ClN2Pd: C, 65.07; H, 7.87; N, 4.46. Found: C, 65.05; H, 7.77;
N, 4.39.
1H NMR (300 MHz, C6D6): 7.23 (t, J = 7.7 Hz, 4H, H1), 7.12 (d,
J = 7.7 Hz, 4H, H2), 7.07 (d, J = 7.6 Hz, 4H, H2), 6.64 (s, 4H, H3),
3.27 (hept, J = 6.8 Hz, 4H, H4), 3.01 (hept, J = 6.8 Hz, 4H, H4), 2.37
(s, 2H, allyl-end syn), 1.39 (d, J = 6.7 Hz, 12H, H5), 1.23 (d, J =
6.7 Hz, 12H, H5), 1.14 (d, J = 6.8 Hz, 12H, H5), 1.08 (d, J = 6.8 Hz,
12H, H5), 0.81 (s, 2H, allyl-end anti), 0.58 (s, 3H, allyl-2Me).
13C{1H} NMR (75 MHz, C6D6): 193.24, 146.58, 146.09, 137.70,
129.22, 123.85, 123.74, 122.60, 71.51, 33.39, 28.89, 28.75, 26.00,
25.96, 25.51, 23.58, 23.34.
1H NMR (300 MHz, CDCl3): δ 7.37 (t, J = 7.7, 2H, H1), 7.33−
7.21 (m, 4H, H2), 7.12 (s, H3), 3.90 (d, J = 3.0, 1H, allyl-end), 3.23
(septet, J = 6.8, 2H, H4), 2.99 (d, J = 1.7, 1H, allyl-end), 2.80 (septet,
J = 6.8, 2H, H5), 2.65 (d, J = 2.9, 1H, allyl-end), 1.72 (d, J = 3.0, 1H,
allyl-end), 1.39 (d, J = 6.7, 6H, H5), 1.26 (d, J = 6.7, 6H, H5), 1.16 (d,
J = 6.9, 6H, H5), 0.99 (d, J = 6.9, 6H, H5), 0.59 (s, 9H, 2-tBu H).
13C{1H} NMR (125.8 MHz, CDCl3): δ 188.04, 146.25, 146.23,
143.23, 136.51, 129.94, 124.50, 124.25, 123.76, 70.27, 68.09, 44.34,
34.04, 29.67, 28.67, 28.44, 26.80, 25.80, 23.11, 22.52.
(μ-2-phenylallyl)(μ-Cl)Pd2(IPr)2 (II-Ph). (η3-2-phenylallyl)Pd(IPr)Cl
(I-Ph; 111.6 mg, 0.172 mmol) and K2CO3 (31.4 mg, 1.3 equiv) were
transferred to a Schlenk flask and placed under dinitrogen. Degassed
ethanol (10 mL) was transferred by cannula into the Schlenk flask
at room temperature, and the reaction mixture was stirred at 40 °C
for 5 h. The volatiles were removed under reduced pressure. The
residue was dissolved in 3/1 pentane/toluene and filtered through
a silica gel plug. The volatiles were then removed under reduced
pressure to give II-Ph (89.6 mg, 91%) as a yellow solid. Anal. Calcd for
C63H81ClN4Pd2: C, 66.22; H, 7.15; N, 4.90. Found: C, 65.93; H, 6.93;
N, 4.80.
(η3-2-methoxyallyl)Pd(IPr)Cl (I-OMe). (2-methoxyallyl)2Pd2(μ-Cl)2
(236 mg, 0.555 mmol) was suspended in diethyl ether (5 mL).
A solution of IPr (431 mg, 1.11 mmol) in diethyl ether (25 mL) was
added to a suspension of (2-methoxyallyl)2Pd2(μ-Cl)2 using a cannula.
The reaction mixture was stirred at room temperature for 1 h. The
resultant diethyl ether solution was filtered through a plug of silica
gel that had been deactivated with 4% triethylamine in diethyl ether,
and the volatiles were removed under reduced pressure. The residue
was triturated with 10% diethyl ether in pentane (5 mL) and washed
with pentane (5 mL) to yield I-OMe (527 mg, 79%) as a pale yellow
powder. Anal. Calcd for C31H43ClN2OPd: C, 61.89; H, 7.20; N, 4.66.
1H NMR (400 MHz, C6D6): 7.27 (t, J = 7.7 Hz, 4H, H1), 7.12 (dd,
J = 7.8, 1.4 Hz, 4H, H2), 7.06 (dd, J = 7.7, 1.3 Hz, 4H, H2), 6.91 (t, J =
7.3 Hz, 1H, 2Ph p-H), 6.72 (t, J = 7.7 Hz, 2H, 2Ph m-H), 6.61 (dd, J =
8.3, 1.2 Hz, 2H, 2Ph o-H), 6.59 (s, 4H, H3), 3.24 (hept, J = 6.8 Hz,
4H, H4), 2.96 (hept, J = 6.8 Hz, 4H, H4), 2.89 (s, 2H, allyl-end syn),
1.28 (d, J = 6.8 Hz, 12H, H5), 1.12 (d, J = 6.8 Hz, 12H, H5), 1.11 (d,
J = 6.9 Hz, 12H, H5) 1.06 (d, J = 6.9 Hz, 12H, H5), 0.97 (s, 2H, allyl-
end anti). 13C{1H} NMR (101 MHz, C6D6): 192.10, 146.57, 146.35,
146.04, 137.50, 129.45, 127.93, 127.23, 124.13, 123.98, 123.36, 123.03,
74.78, 30.93, 28.86, 28.69, 26.01, 25.44, 23.54, 23.21.
1
Found: C, 60.41; H, 7.19; N, 4.50. H and 13C NMR spectra for this
compound are provided below.
1H NMR (400 MHz, C6D6): 7.22 (t, J = 7.6 Hz, 2H, H1), 7.15−
7.10 (m, 4H, H2), 6.65 (s, 2H, H3), 3.36 (hept, J = 6.8 Hz, 2H, H4),
3.30 (dd, J = 3.9 Hz, 3.8 Hz, 1H, allyl-end), 3.18 (hept, J = 6.8 Hz, 2H,
H4), 2.83 (dd, J = 3.8 Hz, 3.2 Hz, 1H, allyl-end), 2.65 (s, 3H,
methoxy-OCH3), 2.21 (d, J = 3.9 Hz, 1H, allyl-end), 1.53 (d, J =
6.7 Hz, 6H, H5), 1.46 (d, J = 3.2 Hz, 1H, allyl-end), 1.44 (d, J =
6.7 Hz, 6H, H5), 1.06 (d, J = 6.8 Hz, 6H, H5), 1.05 (d, J = 6.9 Hz,
6H, H5). 13C{1H} NMR (101 MHz, C6D6): 188.00, 151.72, 146.75,
(μ-2-tert-butylallyl)(μ-Cl)Pd2(IPr)2 (II-tBu). (η3-2-tert-butylallyl)Pd-
(IPr)Cl (I-tBu; 87.2 mg, 0.142 mmol) and K2CO3 (98 mg, 5 equiv)
were transferred to a Schlenk flask and placed under dinitrogen.
Degassed ethanol (5 mL) was transferred by cannula into the Schlenk
flask at room temperature, and the reaction mixture was stirred at
L
Organometallics XXXX, XXX, XXX−XXX