jhet2332-sup-0001-documentS1

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

S15

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.

S2

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.

S5

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. (1) (2) (3) (4) (5) (6)

S21