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DOI: 10.1055/s-0029-1219905
Synthesis of Thiosulfonate-Bridged Bromofluorene Endcapping Reagents
Publikationsverlauf
Publikationsdatum:
22. April 2010 (online)
Abstract
A simple and versatile synthesis of thiosulfonate-bridged bromofluorene end-capping reagents is reported. The novel fluorene-based π-electron-poor aromatic building block was used as end-capping reagent in the synthesis of a polyfluorene-based molecular wire.
Key words
fluorine - halogenation - thiosulfonates - Yamamoto homocoupling - oligomerization
- Supporting Information for this article is available online:
- Supporting Information
- For an interesting perspective on molecular electronics, see:
-
1a
Miller JS. Adv. Mater. 1990, 2: 378 -
1b
Miller JS. Adv. Mater. 1990, 2: 495 -
1c
Miller JS. Adv. Mater. 1990, 2: 603 - 2
Ofir Y.Samanta B.Rotello VM. Chem. Soc. Rev. 2008, 37: 1814 -
3a
Tour JM.Jones L.Pearson V.Lamba JJS.Burgin TP.Whitesides GM.Allara DL.Parikh AN.Atre SV. J. Am. Chem. Soc. 1995, 117: 9529 -
3b
Stuhr-Hansen N.Christensen JB.Harrit N.Bjørnholm T. J. Org. Chem. 2003, 68: 1275 -
4a
Römbke P.Schier A.Wiesbrock F.Schmidbaur H. Inorg. Chim. Acta 2003, 347: 123 -
4b
Römbke P.Schier A.Schmidbaur H. J. Chem. Soc., Dalton Trans. 2001, 2482 - 5
Burdinski D.Blees MH. Chem. Mat. 2007, 19: 3933 - 6
Stachel H.-D.Eckl E.Immerz-Winkler E.Kreiner C.Weigand W.Robl C.Wünsch R.Dick S.Drescher N. Helv. Chim. Acta 2002, 85: 4453 -
7a
Aucott SM.Milton HL.Robertson SD.Slawin AMZ.Walker GD.Woollins JD. Chem. Eur. J. 2004, 10: 1666 -
7b
Aucott SM.Kilian P.Robertson SD.Slawin AMZ.Woollins JD. Chem. Eur. J. 2006, 12: 895 - 8
Aucott SM.Kilian P.Milton HL.Robertson SD.Slawin AMZ.Woollins JD. Inorg. Chem. 2005, 44: 2710 - 9
Bo Z, andYaquin F. inventors; CN 1629113. - 10
Ashe AJ.Kampf JW.Savla PM. Heteroat. Chem. 1994, 5: 113 - 11
Nakano K.Hidehira Y.Takahashi K.Hiyama T.Nozaki K. Angew. Chem. Int. Ed. 2005, 44: 7136 - 12
Grainger RS.Patel B.Kariuki BM. Angew. Chem. Int. Ed. 2009, 48: 4832 - 13
Oxelbark J.Thunberg L.Anderson A.Allenmark S. Acta Chem. Scand. 1999, 53: 710 -
14a
Armarego WLF.Turner EE. J. Chem. Soc. 1956, 1665 -
14b
Stender K.-W.Klar G.Knittel D. Z. Naturforsch., B 1985, 40: 774 - 15 A similar but less constrained ring
system has been reported. Thieno[2,3,4,5-lmn][9,10]dithiaphenantherene-9,9-dioxide was
obtained in low yield using MCPBA. See:
Kimura T.Ishikawa Y.Ogawa S.Nishio T.Iida I.Furukawa N. Tetrahedron Lett. 1992, 33: 6355 - 16
Wang L.Jing H.Bu X.Chang T.Jin L.Liang Y. Catal. Commun. 2007, 8: 80 - For examples of cyclic aromatic disulfides and their properties, see:
-
18a
Goodings EP.Mitchard DA.Owen G. J. Chem. Soc., Perkin Trans. 1 1972, 1310 -
18b
Chiang L.-Y.Meinwald J. Tetrahedron Lett. 1980, 21: 4565 -
18c
Miller EW.Bian SX.Chang CJ. J. Am. Chem. Soc. 2007, 129: 3458 -
19a
Cossu S.Delogu G.Lucchi O.Fabbri D.Fois MP. Synth. Commun. 1989, 19: 3431 -
19b
Zhu-Ohlbach Q.Gleiter R.Rominger F.Schmidt H.-L.Reda T. Eur. J. Org. Chem. 1998, 2409 - 20
Scherf U.List EJW. Adv. Mater. 2002, 14: 477 - 21
Søndergaard R.Strobel S.Bundgaard E.Norrman K.Hansen AG.Albert E.Csaba G.Lugli P.Tornow M.Krebs FC. J. Mater. Chem. 2009, 19: 3899 - 22 Methanethiosulfonate has been shown
to influence the Ca²+ release in the
sarcoplasmic reticulum by selective activation of ryanodine receptors
(RyRs), a key Ca²+ regulatory channel,
see:
Pessah IN. Pest. Manag. Sci. 2001, 57: 941
References and Notes
Complete reduction was monitored by TLC.
23
6,6-Di-
n
-octyl-6
H
-fluorene[4,5-
cde
][1,2]dithiine
(3)
9,9-Di-n-octalyfluorene
(2, 29.5 g, 0.0756 mol) was stirred with n-BuLi (1.6 M in hexane, 192 mL, 0.302
mol) and TMEDA (48 mL, 0.302 mol) at 60 ˚C for 3 h. The
resulting dark red solution was cooled down to -78 ˚C
and diluted with THF (250 mL). Sulfur (24.0 g, 0.755 mol) was added, and
the resulting orange mixture allowed to reach r.t. and stirred for
additional 12 h. This mixture was then washed with a 1 M aq NaOH
solution (this washing completely removes intensively smelling byproducts)
and H2O. The organic layer was separated and the aqueous
layer further extracted with Et2O. The organic layers
were combined, dried with anhyd MgSO4, filtered, and
the solvent removed in vacuo. Purification of the resulting dark
red oil by column chromatography(hexane) gave a yellow oil that
solidified upon standing (20.7 g, 60% yield); mp 43-45 ˚C(hexane).
IR (thin film): 2924, 2852, 1464, 1409, 786, 735 cm-¹. ¹H
NMR (400 MHz, CDCl3): δ = 7.21 (2 H,
t, J = 7.6
Hz), 7.11 (2 H, d, J = 8.0
Hz), 7.05 (2 H, d, J = 7.6
Hz), 1.93-1.89 (4 H, m), 1.27-1.08 (20 H, m),
0.84 (6 H, t, J = 7.0
Hz), 0.73 (4 H, m). ¹³C NMR (100.6
MHz, CDCl3): δ = 150.79, 137.41, 129.30, 125.47,
124.08, 122.00, 56.65, 39.21, 31.76, 29.95, 29.17, 24.01, 22.58,
14.03. Anal. Calcd for (C29H40S2):
C, 76.93; H, 8.90; S, 14.16. Found: C, 75.76; H, 9.52; S, 13.60.
Thiosulfonate-Bridged Fluorene (4)
A
CH2Cl2 solution (100 mL) of 3 (2.32
g, 5.94 mmol), NBS (2.11 g, 11.87 mmol), and silica gel (24 g, 2.0
g mmol-¹ NBS) were stirred at r.t.
for 13 h. The orange mixture obtained was filtered, extracted with
CH2Cl2 and the organic phase washed with H2O.
The organic layers were combined, dried with anhyd MgSO4,
filtered, and the solvent removed under vacuo. After purification
by column chromatography (hexane) a light yellow oil was obtained
(1.9 g, 66% yield). IR (thin film): 2920, 2848, 1392, 1323,
1155, 1136, 1119 cm-¹. ¹H
NMR (400 MHz, CDCl3): δ = 7.81 (1 H,
d, J = 8.0 Hz),
7.63 (1 H, d, J = 8.0
Hz), 7.58 (1 H, t, J = 8.0
Hz), 7.44 (1 H, d, J = 8.0
Hz), 7.36 (1 H, d, J = 8.0
Hz), 7.26 (1 H, d, J = 8.0
Hz), 2.05-2.01 (4 H, m), 1.22-1.07 (20 H, m),
0.82 (6 H, t, J = 8.0
Hz), 0.70 (4 H, m). ¹³C NMR (100.6
MHz, CDCl3): δ = 152.08, 151.54, 137.15,
135.19, 132.35, 129.54, 128.83, 125.95, 124.77, 122.13, 117.61,
56.63, 39.20, 31.75, 29.94, 29.16, 24.01, 22.57, 14.03. Anal. Calcd
for (C29H40S2O2): C,
71.85; H, 8.32; S, 13.23. Found: C, 71.74; H, 8.41; S, 13.24.
Thiosulfonate-Bridged Monobromofluorene (5)
Compound 4 (1.0 g, 2.06 mmol), Br2 (0.22
mL, 9.75 mmol) and concd H2SO4 (15 mL) were
stirred at r.t. overnight. The red mixture obtained was quenched
with H2, and extracted with CH2Cl2.
The organic layers were combined, dried with anhyd MgSO4,
filtered, and the solvent removed under vacuo. After recrystallization
from hexane white crystals were obtained (1.0 g, 86% yield);
mp 75-76 ˚C(hexane). IR (thin film): 2921, 2849,
1393, 1323, 1157, 1138, 1120 cm-¹. ¹H
NMR (400 MHz, CDCl3): δ = 7.84 (1 H,
dd, J = 8.0,
4.0 Hz), 7.64-7.62 (3 H, m), 7.25 (1 H, d, J = 8.0 Hz),
2.04-2.00 (4 H, m), 1.22-1.07 (20 H, m), 0.83
(6 H, t, J = 8.0
Hz), 0.69 (4 H, m). ¹³C NMR (100.6
MHz, CDCl3): δ = 152.47, 150.74, 136.72,
134.91, 134.15, 132.91, 129.71, 128.21, 127.29, 123.23, 118.35,
118.01, 57.71, 39.12, 31.67, 29.76, 29.08, 23.95, 22.52, 13.99.
Anal. Calcd for (C29H39BrO2S2): C,
61.80; H, 6.97; S, 11.38. Found: C, 61.49; H, 7.68; S, 11.05.
Thiosulfonate-Endcapped Oligofluorene (TS-OF)
A
Schlenk flask was charged with 2,7-dibromo-9,9-
di-n-octylfluorene (500 mg, 0.91 mmol),
Ni(cod)2 (599 mg, 2.18 mmol), and 2,2′-bipyridyl
(340.4 mg, 2.18 mmol) under argon. 1,5-Cyclooctadiene (COD, 170 µL,
1.365 mmol) and THF (25 mL) were subsequently added and the mixture heated
up to 60 ˚C for 3 h. After this period the thiosulfonate endcapping
reagent 5 (154 mg, 0.273 mmol) was added
and the mixture heated for additional 3 h. The solution was poured
into aq 2 N HCl and extracted with CHCl3. The organic
layer was washed with a sat. EDTA solution, dried over anhyd MgSO, and
the solvent evaporated to dryness. The residue obtained was Soxhlet-extracted
with MeOH (1 d) and EtOAc (3 d), redissolved in CHCl3 and
reprecipitated into cold MeOH (1:100) to yield the endcapped oligo-fluorene TS-OF (245 mg, 70% yield). The
copolymer showed thermal stability up to 350 ˚C by to thermo-gravimetric
analysis (TGA). GPC (THF): Mn = 4300, Mw = 9190,
PD = 2.13 (after extraction). UV/Vis
(CHCl3): λmax,abs = 360
nm, photoluminescence: λmax,PL = 415
nm. IR (thin film): 2923, 2852, 1506, 1455, 1248, 1177, 1048, 812 cm-¹. ¹H
NMR (400 MHz, CDCl3): δ = 7.83 (br
s, ArH), 7.67 (br s, ArH), 7.38 (br s, ArH), 2.04 (4 H, br s), 1.13
(20 H, br s), 0.81 (6 H, br s). Anal. Calcd for (C319H438O4S4;
4465, n = 9): C, 85.81; H, 9.89; S, 2.87.
Found: C, 84.04; H, 10.33; S, 2.64.