D. Poliakov, A. Rogalyov, I. Shevchenko
FULL PAPER
rated and stored overnight at –15 °C to yield yellow crystals. Yield
45 mg (50%), m.p. 110 °C. 1H NMR (400.07 MHz, C6D6): δ = 0.81
[br., 12 H, CH(CH3)2], 1.23 [br., 12 H, CH(CH3)2], 3.86 [sept, 3JH,H
= 7.03 Hz, 4 H, CH(CH3)2], 7.17–7.30 (m, 5 H, Ph) ppm. 13C NMR
native is that diaminocarbene 3 adds to carbene 6 in this
reaction but catalyses the asymmetrical dimerization of 6
obtained from the dissociation of ylide 10.
(100.61 MHz, C6D6): δ = 22.72 (br.), 54.68 (br.), 112.28 [sept, 2JC,F
1
=
36.00 Hz, C(CF3)2], 115.65 (PhCN), 123.48 (q, JC,F
=
Conclusions
1
285.34 Hz, 1 C, CF3), 123.78 (q, JC,F = 285.34 Hz, 1 C, CF3),
127.02 (s, 1 C, Ph), 128.28 (s, 2 C, Ph), 131.33 (s, 2 C, Ph), 140.22
(s, 1 C, Ph), 171.25 (NCN) ppm. 19F NMR (84.26 MHz, CDCl3,
20 °C): δ = –58.64 (br., 3 F, CF3), –61.64 (br., 3 F, CF3) ppm. 19F
Bis(diisopropylamino)carbene deoxygenates the carbonyl
group of aroylimines to form alkenes. This reaction may
have a more general character, and other alkenes can be
obtained from singlet nucleophilic diaminocarbenes and
ketones that are properly activated and do not contain
acidic hydrogens.
4
NMR (84 MHz, CDCl3, –30 °C): δ = –62.23 (q, JF,F = 6.84 Hz, 3
4
F, CF3), –58.80 (q, JF,F = 6.84 Hz, 3 F, CF3) ppm.
Compound 7c: To a solution of 3 (210 mg, 1 mmol) in hexane
(3 mL), solid 2c (157 mg, 0.5 mmol) was slowly added. The mixture
was stirred for 5 min, and the solution was separated and stored
overnight at –15 °C to give red crystals. Yield 116 mg (46%), m.p.
120–122 °C. 1H NMR (400.07 MHz, C6D6): δ = 1.35 [br., 24 H,
Experimental Section
General: All operations were performed under nitrogen in a dry
box. The solvents were dried by the usual procedures. The NMR
spectra were recorded with Varian Gemini 400 MHz and JEOL
3
CH(CH3)2], 3.95 [sept, JH,H = 7.32 Hz, 4 H, CH(CH3)2], 7.31 (d,
3JH,H = 8.79 Hz, 2 H, Ar), 8.16 (d, 3JH,H = 8.79 Hz, 2 H, Ar) ppm.
13C NMR (100.61 MHz, CDCl3): δ = 23.35 (br.), 54.72 (br.), 112.00
1
FX-90Q spectrometers. The H and 13C chemical shifts are refer-
2
1
(PhCN), 113.30 [sept, JC,F = 35.01 Hz, C(CF3)2], 120.28 (q, JC,F
= 277.71 Hz, CF3), 123.53 (s, 1 C, Ar), 126.62 (s, 2 C, Ar), 131.35
(s, 2 C, Ar), 147.47 (s, 1 C, Ar), 171.06 (NCN) ppm. 19F NMR
(84.26 MHz, CDCl3, 20 °C): δ = –61.86 (br., 6 F, CF3) ppm. 19F
NMR (84 MHz, CDCl3, –30 °C): δ = –61.86 (br., 6 F, CF3) ppm.
enced to tetramethylsilane (TMS) and the 19F chemical shifts are
referenced to CFCl3. The 31P chemical shifts were measured with
85% aqueous H3PO4 as an external standard.
Compound 7a: To a solution of 3 (100 mg, 0.47 mmol) in diethyl
ether (1.5 mL), 2a (70 mg, 0.23 mmol) was added at room tempera-
ture. The resulting solution turned yellow and slightly turbid. After
15 min, the solvent was evaporated in vacuo. The residue was dis-
solved in hexane (0.6 mL) and stored at –15 °C overnight to form
yellow crystals. Yield 60 mg (52%), m.p. 158–160 °C. 1H NMR
Compound 8b: A solution of alkene 7b (0.1 mmol, 46 mg) in CHCl3
(0.7 mL) was stored for 24 h at 30 °C. The solvent was evaporated
in vacuo, yielding a yellow-brown oil (46 mg, 100%). 1H NMR
(400.07 MHz, C6D6), 2:1 rotamer ratio: δ = 0.93 [br., CH(CH3)2],
3
3
1.06 [d, JH,H = 7.81 Hz, CH(CH3)2], 1.21 [d, JH,H = 7.83 Hz,
3
(400.07 MHz, CDCl3): δ = 0.78 [d, JH,H = 6.84 Hz, 6 H,
CH(CH3)2], 1.24 [br. s, C(CH3)2], 1.63 [br. s, C(CH3)2], 3.15 [sept,
3
CH(CH3)2], 1.27 [d, JH,H = 6.84 Hz, 6 H, CH(CH3)2], 1.39 [d,
3
3JH,H
=
6.84 Hz, CH(CH3)2], 3.27 [sept, JH,H
=
6.84 Hz,
3
3JH,H = 6.84 Hz, 6 H, CH(CH3)2], 1.47 [d, JH,H = 6.84 Hz, 6 H,
3
CH(CH3)2], 3.94 [sept, JH,H = 7.81 Hz, CH(CH3)2], 4.05 [sept,
CH(CH3)2], 2.08 (s, 6 H, o-CH3), 2.26 (s, 3 H, p-CH3), 3.54 [sept,
3
3JF,H
= 8.78 Hz, CHC(CF3)2], 4.30 [sept, JF,H = 8.78 Hz,
3
3JH,H = 6.84 Hz, 1 H, CH(CH3)2], 4.02 [sept, JH,H = 6.84 Hz, 2
CHC(CF3)2], 6.98–7.27 (m, Ph), 7.42–7.51 (m, Ph) ppm. 13C NMR
(100.61 MHz, C6D6), 2:1 rotamer ratio: δ = 21.70 [CH(CH3)2],
22.05 [CH(CH3)2], 23.11 [CH(CH3)2], 23.43 [CH(CH3)2], 27.30
[C(CH3)2], 27.57 [C(CH3)2], 43.82 [CH(CH3)2], 45.38 [CH(CH3)2],
51.13 [CH(CH3)2], 51.35 [CH(CH3)2], 61.06 [sept, 2JC,F = 31.28 Hz,
3
H, CH(CH3)2], 4.19 [sept, JH,H = 6.84 Hz, 1 H, CH(CH3)2], 6.83
(s, 2 H, Ar) ppm. 13C NMR (100.61 MHz, CDCl3): δ = 20.94 (s, 2
C, CH3), 21.86 (s, 1 C, CH3), 22.82 (s, 2 C, CH3), 23.85 (s, 4 C,
CH3), 24.43 (s, 2 C, CH3), 53.17 (s, 1 C, CH3), 53.30 (s, 1 C, CH3),
55.56 (s, 2 C, CH3), 112.44 [sept, 1JC,F = 36.62 Hz, C(CF3)2], 113.55
2
CH(CF3)2], 61.26 [sept, JC,F = 29.76 Hz, CH(CF3)2], 80.16
1
(s, 1 C, ArCN), 118.72 (q, JC,F = 280.76 Hz, 1 C, CF3), 122.4 (q,
1
[C(CH3)2], 80.47 [C(CH3)2], 111.81, 118.76, 123.45 (q, JC,F
=
1JC,F = 276.18 Hz, 1 C CF3), 128.61 (s, 2 C, Ar), 135.46 (s, 1 C,
1
286.86 Hz, CF3), 123.79 (q, JC,F = 288.39 Hz, CF3), 126.49 (Ph),
127.32 (Ph), 128.07 (Ph), 128.74 (Ph), 130.57 (Ph), 131.65 (Ph),
133.41 (Ph), 135.06 (Ph), 135.55 (NCN), 142.11 (NCN) ppm. 19F
NMR (84.26 MHz, C6D6), 2:1 rotamer ratio: δ = –66.03 (d, JF,H
= 8.55 Hz, CF3, major rotamer), –65.22 (d, JF,H = 8.55 Hz, CF3,
Ar), 136.59 (s, 1 C, Ar), 137.71 (s, 2 C, Ar), 172.60 (s, 1 C, NCN)
4
ppm. 19F NMR (84.26 MHz, CDCl3): δ = –62.30 (q, JF,F
=
4
7.32 Hz, 3 F, CF3), –59.99 (q, JF,F = 7.32 Hz, 3 F, CF3) ppm.
3
3
Crystal Data for 7a: Data were collected on a Enraf–Nonius CAD4
diffractometer. C26H39F6N3, 507.60, monoclinic, a =
M
=
minor rotamer) ppm.
12.239(4), b = 16.483(5), c = 13.875(4) Å, β = 92.20(2)°, V =
2797(2) Å3, T = 293 K, space group P 21/n, Z = 4, µ(Mo-Kα) =
0.099 mm–1, λ = 0.71069 Å, 5380 reflections measured, 4928 unique
(Rint = 0.0011). Final R indices R1 = 0.0580, wR(F2) = 0.1252 [for
2551 reflections with I/σ(I) Ͼ 3.0].
Compound 8c: A solution of alkene 7c (0.1 mmol, 51 mg) in CHCl3
(0.7 mL) was stored for 78 h at 20 °C and then heated at 50 °C for
30 min. The solvent was evaporated in vacuo, yielding red-black
crystals (51 mg, 100%). Crystals, suitable for X-ray analysis, were
grown from hexane at –15 °C. M.p. 106–108 °C. 1H NMR
(400.07 MHz, CDCl3): 7:1 rotamer ratio, major rotamer: δ = 1.02–
CCDC-651200 contains the supplementary crystallographic data
for 7a. These data can be obtained free of charge from the Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
3
1.10 {br., 12 H, N[CH(CH3)2]2}, 1.28 [d, JH,H = 6.84 Hz, 6 H,
=NCH(CH3)2], 1.54 [d, 6 H, C(CH3)2], 3.45 {sept, 3JH,H = 6.84 Hz,
3
2
H, N[CH(CH3)2]2}, 4.02 [sept, JH,H
=
6.84 Hz,
1
H,
Compound 7b: To a frozen (in liquid nitrogen) solution of 3 (84 mg,
0.4 mmol) in Et2O (1 mL) a solution of 2b (52 mg, 0.19 mmol) in
Et2O (0.4 mL) was slowly added so that the mixture remained solid.
Then the mixture was slowly warmed to room temperature over
20 min whilst stirring. Diethyl ether was evaporated, and hexane
(1 mL) was added to the residue. The hexane solution was sepa-
=NCH(CH3)2], 4.20 [sept, 3JF,H = 7.81 Hz, 1 H, CHC(CF3)2], 7.39
3
3
(d, JH,H = 7.81 Hz, 2 H, Ar), 8.06 (d, JH,H = 7.81 Hz, 2 H, Ar)
ppm. 13C NMR (100.61 MHz, CDCl3): 7:1 rotamer ratio, major
rotamer: δ = 23.32 {N[CH(CH3)2]2}, 23.59 [=NCH(CH3)2], 27.54
[C(CH3)2], 44.40 [=NCH(CH3)2], 51.33 {N[CH(CH3)2]2}, 61.04
2
[sept, JC,F = 28.99 Hz, NCH(CF3)2], 81.56 [C(CH3)2], 109.90
5808
www.eurjoc.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2008, 5805–5809