Nickel Phosphine–Phosphite Complexes
I
purification by flash column chromatography (hexanes/Et2O
98 : 2) as a colourless oil (69 mg, 0.41 mmol, 82 %). The spectral
data were in accordance with those reported in the literature.[19]
Rf 0.14 (hexanes/EtOAc 98 : 2). dH (CDCl3, 400 MHz) 8.41 (1H,
s, Ar–H), 7.99 (1H, d, J 8.6, Ar–H), 7.91 (1H, d, J 8.1, Ar–H),
7.85–7.80 (2H, m, 2 ꢂ Ar–H), 7.58–7.48 (2H, m, 2 ꢂ Ar–H),
2.67 (3H, s, CH3).
(2H, d, J 8.5, 2 ꢂ Ar–H), 7.78 (2H, d, J 8.5, 2 ꢂ Ar–H), 2.64
(3H, s, CH3).
40-(Trifluoromethyl)acetophenone (10k)
Following the general procedure (22 h), using 3-(trifluoromethyl)
phenyl triflate (285mg, 0.970 mmol, 1.00 equiv.), Ni[P(OEt)3]4
(14.0 mg, 0.019 mmol, 2 mol-%), dppe (8.0mg, 0.019mmol,
2 mol-%), Cy2NMe (206mL, 0.970 mmol, 1.00equiv.), butyl
vinyl ether (188mL, 1.46mmol, 1.50equiv.), and toluene (6mL),
the desired ketone 10k was obtained after hydrolysis and puri-
fication by flash column chromatography (hexanes/EtOAc
95 : 5) as a colourless oil (77 mg, 0.41 mmol, 42 %). The spectral
data were in accordance with those reported in the literature.[19]
Rf 0.24 (hexanes/EtOAc 95 : 5). dH (CDCl3, 300 MHz) 8.21 (1H,
s, Ar–H), 8.14 (1H, d, J 7.8, Ar–H), 7.82 (1H, d, J 7.8, Ar–H),
7.62 (1H, ‘t’, J 7.8, Ar–H), 2.65 (3H, s, CH3). dF (CDCl3,
282 MHz) ꢃ63.2.
40-Phenylacetophenone (10f)
Following the general procedure, using 4-(1,10-biphenyl) triflate
(309 mg, 1.02 mmol, 1.00 equiv.), Ni[P(OEt)3]4 (15.0 mg,
0.020 mmol, 2 mol-%), DPPE (8.0 mg, 0.020 mmol, 2 mol-%),
Cy2NMe (216 mL, 1.02 mmol, 1.00 equiv.), butyl vinyl ether
(196 mL, 1.53 mmol, 1.50 equiv.), and toluene (6 mL), the
desired ketone 10f was obtained after hydrolysis and purifica-
tion by flash column chromatography (hexanes/EtOAc 95 : 5) as
a white solid (33 mg, 0.17 mmol, 17 %). The spectral data were
in accordance with those reported in the literature.[62] Rf 0.28
(hexanes/EtOAc 90 : 10). dH (CDCl3, 300 MHz) 8.04 (2H, d, J
8.4, 2 ꢂ Ar–H), 7.69 (2H, d, J 8.4, 2 ꢂ Ar–H), 7.67–7.59 (2H, m,
2 ꢂ Ar–H), 7.54–7.36 (3H, m, 3 ꢂ Ar–H), 2.64 (3H, s, CH3).
(E/Z)-1-(2-Methoxy-4-(prop-1-en-1-yl)phenyl)ethanone
(10n)
Following the general procedure (20 h), using 4-allyl-2-
methoxyphenyl triflate (109 mg, 0.380 mmol, 1.00 equiv.), Ni[P
(OPh)3]4 (25.0 mg, 0.019 mmol, 5 mol-%), DPPF (11 mg,
0.019 mmol, 5 mol-%), Cy2NMe (250 mL, 1.14 mmol,
3.00 equiv.), butyl vinyl ether (213 mL, 1.52 mmol, 4.00 equiv.),
and 1,4-dioxane (3 mL), the title compound 10n was obtained
after hydrolysis and purification by flash column chromato-
graphy (hexanes/EtOAc 98 : 2 - 96 : 4) as a colourless oil
(10 : 6 E/Z mixture, 65 mg, 0.34 mmol, 89 %). The spectral data
were in accordance with those reported in the literature.[19] Rf
0.13 (hexanes/EtOAc 98 : 2). Major isomer (E): dH (CDCl3,
400 MHz) 7.73 (1H, d, J 8.1, Ar–H), 6.99 (1H, dd, J 8.1, 1.3, Ar–
H), 6.90 (1H, s, Ar–H), 6.48–6.32 (2H, m, HC¼CHCH3), 3.94
(3H, s, OMe), 2.62 (3H, s, C(O)Me), 1.93 (3H, d, J 5.0 Hz,
HC¼CHCH3). Minor isomer (Z): dH (CDCl3, 400 MHz) 7.76
(1H, d, J 8.0, Ar–H), 6.96 (1H, d, J 8.0, Ar–H), 6.88 (1H, s,
Ar–H), 6.47–6.33 (1H, m, HC¼CHCH3), 5.97–5.87 (1H, m,
HC¼CHCH3), 3.94 (3H, s, OMe), 2.63 (3H, s, C(O)Me), 1.95
(3H, dd, J 7.0, 2.1, HC¼CHCH3).
1,3-Diacetylbenzene (10h)
Following the general procedure, using 3-acetylphenyl triflate
(274 mg, 1.02 mmol, 1.00 equiv.), Ni[P(OEt)3]4 (14.0 mg,
0.020 mmol, 2 mol-%), DPPE (8.0 mg, 0.020 mmol, 2 mol-%),
Cy2NMe (217 mL, 1.02 mmol, 1.00 equiv.), butyl vinyl ether
(198 mL, 1.53 mmol, 1.50 equiv.), and toluene (6 mL),
the desired ketone 10h was obtained after hydrolysis and puri-
fication by flash column chromatography (hexanes/EtOAc
90 : 10 - 80 : 20) as a colourless oil (109 mg, 0.670 mmol,
66 %). The spectral data were in accordance with those reported
in the literature.[63] Rf 0.12 (hexanes/EtOAc 90 : 10). dH (CDCl3,
300 MHz) 8.52 (1H, t, J 1.8, Ar–H), 8.15 (2H, dd, J 7.8, 1.8,
2 ꢂ Ar–H), 7.58 (1H, t, J 7.8, Ar–H), 2.66 (6H, s, 2 ꢂ CH3).
1,4-Diacetylbenzene (10i)
Following the general procedure, using 4-acetylphenyl triflate
(256 mg, 0.95 mmol, 1.00 equiv.), Ni[P(OEt)3]4 (13.0 mg,
0.019 mmol, 2 mol-%), DPPE (7.0 mg, 0.019 mmol, 2 mol-%),
Cy2NMe (202 mL, 0.95 mmol, 1.00 equiv.), butyl vinyl ether
(184 mL, 1.43 mmol, 1.50 equiv.), and toluene (6 mL), the
desired ketone 10i was obtained after hydrolysis and purifica-
tion by flash column chromatography (hexanes/EtOAc 80 : 20)
as a pale-yellow solid (87 mg, 0.54 mmol, 56 %). The spectral
data were in accordance with those reported in the literature.[63]
Rf 0.40 (hexanes/EtOAc 70 : 30). dH (CDCl3, 300 MHz,) 8.03
(4H, s, 4 ꢂ Ar–H), 2.65 (6H, s, 2 ꢂ CH3).
General Procedure for Ammonia Arylation
An oven-dried vial (35 ꢂ 12 mm) equipped with a PTFE-sealed
screw cap was loaded with a magnetic stirrer bar, ((ꢁ)-binap)
Ni[P(OPh)3]2ꢀ2PhCH3 (9) (39 mg, 25 mmol, 5 mol-%), (ꢁ)-binap
(15 mg, 25 mmol, 5 mol-%), and the corresponding aryl halide
(0.50 mmol, 1.0 equiv.). The vial was then transferred into an
argon-filled glovebox, where NaOtBu (216 mg, 2.20 mmol,
4.40 equiv.) and NH3 (0.5 M in 1,4-dioxane, 3.0 mL, 1.5 mmol,
3.0 equiv.) were added. The reaction vial was capped, removed
from the glovebox, and placed into a preheated oil bath at 1208C
to stir for 18 h. On cooling, the reaction mixture was diluted with
Et2O (15 mL), and washed with 1 M NaOH (10 mL) and H2O
(2 ꢂ 10 mL). The organic layer was fused onto silica and puri-
fied via flash column chromatography (EtOAc/hexanes or
EtOAc/MeOH) to give the corresponding aniline.
4-Acetylbenzonitrile (10j)
Following the general procedure, using 4-cyanophenyl triflate
(115 mg, 0.460 mmol, 1.00 equiv.), Ni[P(OEt)3]4 (7.0 mg,
0.0092 mmol, 2 mol-%), DPPE (4.0mg, 0.0092 mmol, 2 mol-%),
Cy2NMe (98 mL, 0.46 mmol, 1.00 equiv.), butyl vinyl ether
(89 mL, 0.69 mmol, 1.50 equiv.), and toluene (3 mL), the desired
ketone 10j was obtained after hydrolysis and purification by
flash column chromatography (hexanes/EtOAc 100 : 0 -
90 : 10) as a tan solid (57 mg, 0.39 mmol, 85 %). The spectral
data were in accordance with those reported in the literature.[19]
Rf 0.26 (hexanes/EtOAc 90 : 10). dH (CDCl3, 400 MHz) 8.04
o-Toluidine (19a)
Following the general procedure using 2-chlorotoluene (60 mL,
0.50 mmol), the desired compound 19a was obtained after
purification via flash column chromatography (hexanes/EtOAc
90 : 10) as a light-brown liquid (34 mg, 0.32 mmol, 64 %). The