Supplementary Material
Microwave-Assisted Dibromoolefination of Aromatic and
Heteroaromatic Aldehydes and Ketones
Djawed Nauroozi,1 Clemens Bruhn, Sven Fürmeier, Jörn-Uwe Holzhauer and Rüdiger Faust*
Institute for Chemistry and CINSaT – Center for Interdisciplinary Nanostructure Science and
Technology, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany.
1
Current address: Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Table of contents
Experimental
S2
Typical procedure
S2
Characterization data of 1,1-dibromo-1-alkenes
S2
1
S6
H and 13C NMR spectra of all compounds
Microwave synthesis protocol
S14
References
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Experimental
NMR Instrumentation
The 1H- and 13C-NMR spectra were recorded in CDCl3 with a 500 MHz spectrometer
(Varian) operating in the FT mode at 500 MHz (1H) and at 125 MHz (13C), respectively.
Unless otherwise stated, the 1H-chemical shifts of all compounds are referenced to the
residual peaks of CDCl3 at  = 7.24 ppm (vs TMS). The 13C-resonances are referenced to the
central peak of CDCl3 at  = 77.0 ppm (vs. TMS).
In case of 9H-Dibromomethylene-4,5-diazafluorene, the 1H- and 13C-NMR spectra were
recorded in THF-d8 with a 400 MHz spectrometer (Varian) operating in the FT mode at 400
MHz (1H) and at 100 MHz (13C), respectively. The 1H-chemical shifts are referenced to the
residual peaks of THF at = 3.58 ppm (vs TMS). The 13C-resonances are referenced to the
central peak of THF at  = 67.57 ppm (vs. TMS).
Mass spectrometry
Mass spectra were recorded on a Finnigan LCQDECA (ThermoQuest) using APCI ionisation
technique, calibrated with sodium formate cluster and CH2Cl2/MeOH (1:4 vv) as the solvent.
The HR-MS were recorded on a time of light spectrometer (micrOTOF - Bruker Daltonics)
using an Apollo “Ion Funnel” electrospray ionisation as the ion source.
Melting Point
Melting points were determined with a Büchi M-565 apparatus and are uncorrected.
Typical Procedure:
Diazafluoren-9-one1 1 (300 mg, 1.65 mmol), CBr4 (2 equiv., 1.09 g, 3.29 mmol) and PPh3 (4
equiv., 1.73 g, 6.59 mmol) were placed into a microwave vial, which was purged with argon.
Dry CH2Cl2 was added to the mixture and the vial was capped tightly and put into the
microwave reactor (CEM Discover SP or Biotage® Initiator Classic, each monomode
apparatus). After 20 min irradiation (80 °C, 3.5 bar internal pressure, 100 W) the reaction
mixture was cooled and poured onto a plug of silica gel. The silica gel was washed with an
additional amount of CH2Cl2 (100 mL) before the eluate was evaporated on the rotary
evaporator to dryness. The pure product was obtained by recrystallization from acetone to
furnish 2 (310 mg, 55 %) as colorless needles.
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Characterisation data of 1,1-dibromo-1-alkenes
(2,2-Dibromovinyl)benzene2
Yield: 555 mg (75 %), colorless oil.
1
H-NMR:  = 7.35-7.49 (m, 3 H), 7.20-7.31 (m, 3 H).
C-NMR:  = 136.83; 135.17; 128.46; 128.32; 128.29; 89.55.
13
(2,2-Dibromovinyl)-4-nitrobenzene3
Yield: 580 mg (95 %), colorless oil.
1
H-NMR:  = 8.24 (d, J = 8.9 Hz, 2 H), 7.71 (d, J = 8.4 Hz, 2 H), 7.51 (s, 1 H).
C-NMR:  = 147.18; 141.44; 134.87; 129.17; 123.71; 94.07.
13
2-[2,2-Dibromovinyl]pyridine
Yield: 540 mg (73 %), yellow oil.
The compound slowly decomposed in CDCl3.
1
H-NMR:  = 8.55 (d, J = 5.09 Hz, 1 H), 7.64 (m, 2 H), 7.57 (s, 1 H), 7.15 (m, 1 H).
13
C-NMR:  = 153.55; 149.30; 136.93; 136.03; 123.25; 122.70; 92.90.
S3
2-[2,2-Dibromovinyl]thiophene4
Yield: 540 mg (75 %), colorless solid.
1
H-NMR:  = 7.55 (s, 1 H), 7.28 (d, J = 5.2 Hz, 1 H), 7.15 (d, J = 3.7 Hz, 1 H), 6.93 (m, 1 H).
C-NMR:  = 138.06; 133.66; 130.05; 128.50; 126.51; 86.97.
13
1,1-Dibromo-2,2-di(2-pyridyl)ethene
H-NMR:  = 8.60 (ddd, J = 4.2 Hz, 2.7 Hz, 0.7 Hz, 2 H), 7.75 (dd, J = 6.1 Hz, 1.4 Hz, 2 H),
7.65 (dd, J = 7.8 Hz, 1.7 Hz, 2H), 7.24 (ddd, J = 5.1 Hz, 4.2 Hz, 1.5 Hz, 2H).
1
C-NMR:  = 157.85; 149.54; 146.18; 136.93; 125.06; 123.11; 96.08.
13
mp: 120 °C (recrystallisation from acetone)
HRMS/ESI (+): m/z = 338.9125 , calculated [C12H9Br2N2] = 338.9127.
X-ray diffraction: The crystal structure is solved and details can be obtained from the
Cambridge Crystallographic Data Centre with deposition number 854588.
S4
9,10-bis(dibromomethylidene)-9,10-dihydroanthracene5
Yield: 600 mg (80 %), colorless solid.
1
H-NMR:  = 7.85 (m, 4 H), 7.30 (m, 4 H).
C-NMR:  = 139.47; 135.83; 127.61; 126.97; 90.31.
13
9H-Dibromomethylene-4,5-diazafluorene
The compound slowly decomposed in CDCl3. Therefore, in addition, NMR measurements
were performed in THF-d8.
H-NMR (CDCl3):  = 8.79 (dd, J = 5.0 Hz, 1.5 Hz, 2 H), 7.99 (dd, J = 7.5 Hz, 1.5 Hz, 2 H),
7.35 (dd, J = 7.1 Hz, 4.8 Hz, 2H);
1
H NMR (THF-d8): δ = 8.96 (dd, J = 8.2 Hz, 1.0 Hz, 2 H), 8.69 (dd, J = 4.7 Hz, 1.3 Hz, 2H),
7.37 (dd,J = 8.2 Hz, 4.7 Hz, 2H);
1
C-NMR (CDCl3):  = 157.15; 155.14; 150.76; 132.56; 131.41; 123.00; 95.14;
C NMR (THF-d8):  = 158.77; 151.81; 135.67; 134.02; 133.17; 123.74; 95.74;
13
13
mp: 164 °C (recrystallisation from acetone)
HRMS/ESI (+): m/z = 336.8977 , calculated [C12H7Br2N2] = 336.8971.
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1,1-dibromo-3,3,3-trifluoro-2-phenylpropene6
Yield: 860 mg (91 %), colorless oil.
1
H-NMR:  = 7.45-7.40 (m, 3H), 7.24-7.20 (m, 2H),
C-NMR:  = 137.60 (q, J = 32.64 Hz); 135.77; 129.61; 129.05; 128.92; 122.15(q, J =
276.02 Hz); 101.90;
13
2,6-bis(1,1-dibromoprop-1-en-2-yl)pyridine
Br
Br
Br
Br
N
Yield: 740 mg (85 %), yellow oil.
1
H-NMR:  = 7.71 (t, J = 7.74 Hz, 1H), 7.27 (d, J = 7.79 Hz, 2H), 2.26 (s, 6H).
C-NMR:  = 159.02; 142.29; 137.00; 122.43; 90.54; 29.78.
13
MS/ESI (+): m/z = 475.
S6
1,1-Dibromo-2-(2-pyridyl)-2-phenylethene
Br
Br
N
Yield: 128 mg (23 %), yellow oil.
1
H-NMR:  = 8.64 (s (br), 1H), 7.71 (dd, J = 1.46 Hz, 7.76 Hz, 1H), 7.41-7.30 (m, 7H).
C-NMR:  = 158.65; 149.23; 146.53; 139.84; 137.26; 131.12; 129.05; 127.32; 124.43;
122.97; 93.78.
13
MS/ESI (+): m/z = 340.
3-Dibromomethylidene-1,5-bis(2-thienyl)-1,4-pentadiyne7
Br
Br
S
S
Yield: 200 mg (41 %), dark orange solid.
H-NMR:  = 7.37 (dd, J = 1.13 Hz, 5.12 Hz, 2H), 7.35 (dd, J = 1.13 Hz, 3.68 Hz, 2H), 7.02
(dd, J = 3.68 Hz, 5.12 Hz, 2H),
1
C-NMR:  = 133.26; 128.91; 127.44; 122.01; 107.76; 89.39; 82.35.
13
S7
1H
and 13C NMR spectra of all compounds
(2,2-Dibromovinyl)benzene
S8
(2,2-Dibromovinyl)-4-nitrobenzene
S9
2-[2,2-Dibromovinyl]pyridine
S10
2-[2,2-Dibromovinyl]thiophene
S11
1,1-Dibromo-2,2-di(2-pyridyl)ethene
S12
9,10-bis(dibromomethylidene)-9,10-dihydroanthracene
S13
9H-Dibromomethylene-4,5-diazafluorene in CDCl3
S14
9H-Dibromomethylene-4,5-diazafluorene in THF-d8
S15
1,1-dibromo-3,3,3-trifluoro-2-phenylpropene
S16
2,6-bis(1,1-dibromoprop-1-en-2-yl)pyridine
Br
Br
Br
N
S17
Br
1,1-Dibromo-2-(2-pyridyl)-2-phenylethene
Br
N
S18
Br
3-Dibromomethylidene-1,5-bis(2-thienyl)-1,4-pentadiyne7
Br
Br
S
S
S19
Microwave synthesis protocol
S20
References
Plater, M. J.; Kemp, S.; Lattmann, E. J. Chem. Soc., Perkin Trans. 1 2000, 971.
Uenishi, J.; Iwamoto, T.; Ohmi, M. Tetrahedron Lett. 2007, 1237.
Jacobsen, M. F.; Moses, J. E.; Adlington, R. M.; Baldwin, J. E. Tetrahedron 2006, 1675.
Arai, N.; Miyaoku, T.; Ternya, S.; Mori, A. Tetrahedron Lett. 2008, 1000.
Donovan, P. M.; Scott, L. T. J. Am. Chem. Soc. 2004, 126, 3108.
Morken, P. A.; Bachand, P. C.; Swenson, D. C.; Burton, D. J. J. Am. Chem. Soc. 1993,
115, 5430.
(7) Eisler, S.; Chahal, N.; McDonald, R.; Tykwinski, R. R., Chem. Eur. J. 2003, 9, 2542.
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