Synthesis of m-Phenylene Ethynylene Oligomers
(m, 12H), 3.88-3.82 (m, 12H), 3.74-3.61 (m, 36H), 3.52-3.50
(m, 12H), 3.334 (s, 3H), 3.328 (s, 3H), 3.321 (s, 12H), 2.82 (s,
3H), 2.80 (s, 3H), 2.79 (s, 3H), 2.78 (s, 3H), 2.75 (s, 3H), 2.74 (s,
3H), 1.13 (s, 21H); 13C NMR (100 MHz, CDCl3) δ 165.6, 165.5,
165.4, 164.7, 148.1, 147.6, 147.07, 147.06, 147.03, 140.5, 133.7,
133.43, 133.37, 133.03, 129.4, 128.39, 128.37, 128.1, 124.7, 124.19,
124.11, 124.09, 124.07, 124.06, 123.9, 123.8, 123.6, 104.3, 101.1,
96.9, 92.6, 92.4, 92.2, 92.18, 92.15, 91.9, 72.1, 70.91, 70.89, 70.83,
70.80, 69.4, 69.33, 69.28, 64.7, 64.63, 64.57, 59.24, 59.22, 27.6,
20.18, 20.17, 20.15, 18.9, 11.4; GPC PDI ) 1.02; MS (MALDI)
(C111H141IO30Si) calcd 2133.27 ([M + Na+]), found 2132.59 ([M
+ Na+]). HPLC (1.0 mL/min, 98:2 CHCl3/iPrOH for 10 min, 93:7
CHCl3/iPrOH for 20 min, retention time 21.907 min) indicated
>94% purity.
(I)-H-Me-H-H-Me-H-(TIPS) (8). Using the procedure for 7, we
obtained 8 (141.5 mg, 0.069 mmol, 88%) as a yellow waxy solid:
1H NMR (400 MHz, CDCl3) δ 8.34 (t, J ) 1.6 Hz, 1H), 8.20-
8.15 (m, 9H), 8.14 (t, J ) 1.6 Hz, 1H), 8.09 (t, J ) 1.6 Hz, 1H),
8.07 (t, J ) 1.6 Hz, 1H), 7.91 (t, J ) 1.6 Hz, 2H), 7.80 (t, J ) 1.6
Hz, 1H), 4.53-4.49 (m, 12H), 3.88-3.84 (m, 12H), 3.73-3.62
(m, 36H), 3.53-3.50 (m, 12H), 3.339 (s, 3H), 3.331 (s, 3H), 3.327
(s, 9H), 3.324 (s, 3H), 2.77 (s, 3H), 2.75 (s, 3H), 1.12 (s, 21H);
13C NMR (100 MHz, CDCl3) δ 165.5, 165.4, 165.35, 165.3, 164.6,
147.4, 144.3, 139.0, 138.7, 138.6, 133.7, 133.6, 133.5, 133.2,
132.96, 132.92, 132.5, 132.22, 132.18, 131.3, 131.0, 128.37, 128.33,
125.3, 124.7, 124.07, 124.03, 123.84, 123.81, 123.79, 123.75,
123.71, 123.63, 108.1, 105.0, 93.6, 93.3, 92.8, 92.7, 92.6, 91.8,
89.26, 89.24, 89.23, 88.76, 88.68, 88.46, 72.1, 70.85, 70.81, 70.79,
69.32, 69.30, 69.28, 69.24, 67.8, 64.90, 64.82, 64.76, 64.63, 64.61,
59.25, 59.22, 29.3, 24.1, 18.5, 11.4; GPC PDI ) 1.03; MS (MALDI)
(C107H133IO30Si) calcd 2077.16 ([M + Na+]), found 2076.92 ([M
+ Na+]). HPLC (1.0 mL/min, 98:2 CHCl3/iPrOH for 10 min, 93:7
CHCl3/iPrOH for 20 min, retention time 21.810 min) indicated
>93% purity.
(m, 20H), 3.35-3.34 (m, 30H), 1.13 (s, 21H); GPC PDI ) 1.04;
MS (MALDI) (C137H165IO40Si) calcd 3210.35 ([M + Na+]), found
3208.71 ([M + Na+]). HPLC (1.0 mL/min, 98:2 CHCl3/iPrOH for
10 min, 93:7 CHCl3/iPrOH for 20 min, retention time 25.296 min)
indicated >91% purity.
I-(H)12-(TIPS) (12). Using the procedure for 7, we obtained 12
(213.2 mg, 0.057 mmol, 73%) as a yellow waxy solid: 1H NMR
(400 MHz, CDCl3) δ 8.33 (t, J ) 1.6 Hz, 1H), 8.19-8.12 (m, 21H),
8.11 (t, J ) 1.6 Hz, 1H), 8.08 (t, J ) 1.6 Hz, 1H), 8.04 (t, J ) 1.6
Hz, 1H), 7.89-7.85 (m, 10H), 7.79 (t, J ) 1.6 Hz, 1H), 4.51-
4.48 (m, 24H), 3.86-3.84 (m, 24H), 3.72-3.61 (m, 72H), 3.51-
3.49 (m, 24H), 3.326-3.315 (m, 36 H), 1.11 (s, 21H); GPC PDI
) 1.04; MS (MALDI) (C137H165IO40Si) calcd 3790.98 ([M + Na+]),
found 3789.6 ([M + Na+]). HPLC (1.0 mL/min, 98:2 CHCl3/iPrOH
for 10 min, 93:7 CHCl3/iPrOH for 20 min, retention time 30.570
min) indicated >89% purity.
I-(H)14-(TIPS) (13). Using the procedure for 7, we obtained 13
(170.5 mg, 0.039 mmol, 50%) as a yellow waxy solid: 1H NMR
(400 MHz, CDCl3) δ 8.34 (t, J ) 1.6 Hz, 1H), 8.23-8.16 (m, 25H),
8.13 (t, J ) 1.6 Hz, 1H), 8.09 (t, J ) 1.6 Hz, 1H), 8.06 (t, J ) 1.6
Hz, 1H), 7.90-7.87 (m, 12H), 7.80 (t, J ) 1.6 Hz, 1H), 4.53-
4.51 (m, 28H), 3.87-3.85 (m, 28H), 3.73-3.62 (m, 84H), 3.52-
3.51 (m, 28H), 3.34-3.33 (m, 42H), 1.12 (s, 21H); GPC PDI )
1.04; MS (MALDI) (C233H273IO70Si) calcd 4371.60 ([M + Na+],
found 4369.30 ([M + Na+]).
I-(H)16-(TIPS) (14). Using the procedure for 7, we obtained 14
(181.6 mg, 0.037 mmol, 47%) as a yellow waxy solid: 1H NMR
(400 MHz, CDCl3) δ 8.34 (t, J ) 1.6 Hz, 1H), 8.17-8.14 (m, 29H),
8.13 (t, J ) 1.6 Hz, 1H), 8.08 (t, J ) 1.6 Hz, 1H), 8.05 (t, J ) 1.6
Hz, 1H), 7.89-7.86 (m, 14H), 7.80 (t, J ) 1.6 Hz, 1H), 4.52-
4.50 (m, 32H), 3.87-3.85 (m, 32H), 3.73-3.63 (m, 96H), 3.52-
3.50 (m, 32H), 3.33-3.32 (m, 48H), 1.12 (s, 21H); GPC PDI )
1.05; MS (MALDI) (C265H309IO80Si) calcd 4952.22 ([M + Na+]),
found 4948.40 ([M + Na+]).
(I)-H-H-H-H-H-H-(TIPS) (9). Using the procedure for 7, we
obtained 9 (137.2 mg, 0.068 mmol, 87%) as a yellow waxy solid:
1H NMR (400 MHz, CDCl3) δ 8.35 (t, J ) 1.6 Hz, 1H), 8.21-
8.17 (m, 9H), 8.14 (t, J ) 1.6 Hz, 1H), 8.10 (t, J ) 1.6 Hz, 1H),
8.07 (t, J ) 1.6 Hz, 1H), 7.90-7.88 (m, 4H), 7.81 (t, J ) 1.6 Hz,
1H), 4.54-4.49 (m, 12H), 3.88-3.85 (m, 12H), 3.74-3.63 (m,
36H), 3.54-3.52 (m, 12H), 3.35 (s, 3H), 3.343 (s, 3H), 3.341 (s,
3H), 3.338 (s, 9H), 1.12 (s, 21H); 13C NMR (100 MHz, CDCl3) δ
165.4, 165.3, 165.2, 144.4, 139.2, 138.8, 138.6, 133.2, 133.10,
133.05, 133.0, 132.99, 132.5, 132.3, 132.2, 131.3, 131.3, 131.0,
125.0, 124.7, 123.9, 123.83, 123.81, 123.80, 123.79, 123.66, 123.4,
105.0, 93.6, 93.3, 89.7, 89.4, 89.28, 89.25, 89.22, 89.18, 88.98,
88.49, 72.12, 72.10, 70.87, 70.85, 70.83, 69.30, 69.28, 69.24, 64.88,
64.81, 64.74, 59.25, 59.23, 18.9, 11.4; GPC PDI ) 1.03; MS
(MALDI) (C105H129IO30Si) calcd 2049.11 ([M + Na+]), found
2049.83 ([M + Na+]). HPLC (1.0 mL/min, 98:2 CHCl3/iPrOH for
10 min, 93:7 CHCl3/iPrOH for 20 min, retention time 21.976 min)
indicated >96% purity.
I-(H)8-(TIPS) (10). Using the procedure for 7, we obtained 10
(180.4 mg, 0.069 mmol, 89%) as a yellow waxy solid: 1H NMR
(400 MHz, CDCl3) δ 8.34 (t, J ) 1.6 Hz, 1H), 8.20-8.16 (m, 13H),
8.13 (t, J ) 1.6 Hz, 1H), 8.09 (t, J ) 1.6 Hz, 1H), 8.06 (t, J ) 1.6
Hz, 1H), 7.90-7.87 (m, 6H), 7.81 (t, J ) 1.6 Hz, 1H), 4.53-4.47
(m, 16H), 3.87-3.83 (m, 16H), 3.73-3.62 (m, 48H), 3.53-3.50
(m, 16H), 3.332-3.329 (m, 24H), 1.13 (s, 21H); GPC PDI ) 1.03;
MS (MALDI) (C137H165IO40Si) calcd 2629.73 ([M + Na+]), found
2627.55 ([M + Na+]). HPLC (1.0 mL/min, 98:2 CHCl3/iPrOH for
10 min, 93:7 CHCl3/iPrOH for 20 min, retention time 24.558 min)
indicated >93% purity.
I-(H)18-(TIPS) (15). Using the procedure for 7, we obtained 15
(180.6 mg, 0.032 mmol, 42%) as a yellow waxy solid: 1H NMR
(400 MHz, CDCl3) δ 8.33 (t, J ) 1.6 Hz, 1H), 8.21-8.15 (m, 33H),
8.12 (t, J ) 1.6 Hz, 1H), 8.08 (t, J ) 1.6 Hz, 1H), 8.05 (t, J ) 1.6
Hz, 1H), 7.89-7.86 (m, 16H), 7.80 (t, J ) 1.6 Hz, 1H), 4.52-
4.50 (m, 36H), 3.86-3.85 (m, 36H), 3.73-3.63 (m, 108H), 3.52-
3.50 (m, 36H), 3.33-3.32 (s, 54), 1.12 (s, 21H); GPC PDI ) 1.04;
MS (MALDI) (C297H345IO90Si) calcd 5532.84 ([M + Na+]), found
5530.67 ([M + Na+]).
2-[2-(2-Methoxyethoxy)ethoxy]ethyl-3-bromo-5-trimethyl-
silanylethynylbenzoate (16). 2-[2-(2-Methoxyethoxy)ethoxy]-
ethyl-5-bromo-3-iodobenzoate (5) (10 g, 21.18 mmol) was added
to a 250 mL round-bottom flask fitted with a stir bar and Pd(PPh3)2-
Cl2 (0.222 g, 0.32 mmol) and CuI (0.225 g, 1.18 mmol). A solution
of THF (14 mL) and triethylamine (45 mL) was then added to the
reaction mixture. Subsequently, trimethylsilylacetylene (30 mL, 211
mmol) was added to the reaction mixture. Within 10 min, the
reaction darkened and salts precipitated. The suspension was then
filtered, transferred with ether into a separatory funnel, washed with
saturated ammonium chloride (2 × 70 mL), and then dried over
magnesium sulfate. The solvent was removed under vacuum to
produce a dark brown oil which was purified by silica gel column
chromatography (3:1 hexanes/EtOAc) to give 16 (8.4 g, 8.9 mmol,
89%) as a light orange oil:
1H NMR (500 MHz, CDCl3) δ 8.04 (s,
1H), 7.98 (s, 1H), 7.70 (s, 1H), 4.42-4.41 (m, 2H), 3.77-3.76
(m, 2H), 3.64-3.57 (m, 6H), 3.47-3.46 (m, 2H), 3.30 (s, 3H),
0.19 (s, 9H); 13C NMR (125 MHz, CDCl3) δ 164.7, 138.7, 132.6,
132.1, 131.8, 125.5, 122.2, 102.4, 97.3, 72.1, 70.81, 70.78, 70.77,
69.2, 64.8, 59.2, -0.02; MS (FD) (C19H27BrO5Si) calcd 443.4,
found 444.1. Anal calcd for C19H27BrO5Si: C, 51.47; H, 6.14.
Found: C, 51.28; H, 6.40.
I-(H)10-(TIPS) (11). Using the procedure for 7, we obtained 11
(187.0 mg, 0.059 mmol, 75%) as a yellow waxy solid: 1H NMR
(400 MHz, CDCl3) δ 8.35 (t, J ) 1.6 Hz, 1H), 8.21-8.17 (m, 17H),
8.14 (t, J ) 1.6 Hz, 1H), 8.10 (t, J ) 1.6 Hz, 1H), 8.07 (t, J ) 1.6
Hz, 1H), 7.91-7.87 (m, 8H), 7.81 (t, J ) 1.6 Hz, 1H), 4.53-4.49
(m, 20H), 3.88-3.84 (m, 20H), 3.74-3.63 (m, 60H), 3.54-3.52
2-[2-(2-Methoxyethoxy)ethoxy]ethyl-3-bromo-4-methyl-5-tri-
methylsilanylethynylbenzoate (17). Using the procedure for 16,
we obtained 17 (2.04 g, 4.47 mmol, 87.8%) as a light yellow oil:
1H NMR (400 MHz, CDCl3) δ 8.15 (d, J ) 1.5 Hz, 1H), 8.05 (d,
J. Org. Chem, Vol. 71, No. 14, 2006 5289