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product was purified via flash column chromatography,
where it was eluted first with hexane and then with ethyl ac-
etate. The product-containing fractions (confirmed using
TLC) were vaporized to collect the final protected amine as a
white solid (0.92 g, M ¼ 459.037 Da, 2.00 mmol, yield 52%).
(m, ACH2AOACH3), 3.36 (s, ACH2AOCH3), and 1.51 (s,
AC(CH3)3). GPC results: for long-chain length fraction Mw
¼
12,591 Da, Mn ¼ 6822 Da, Mp ¼ 8661, and Da, Pd ¼ 1.85;
for short-chain length fraction: Mw ¼ 8376 Da, Mn ¼ 3818
Da, Mp ¼ 3812 Da, and Pd ¼ 2.19. Small amounts of very
high-molecular weight polymer were also detected (they
were beyond the range of the polystyrene standards).
1
TLC (hexane: ethyl acetate 1:1 (v/v)) Rf ¼ 0.48. H NMR 300
MHz, CDCl3, d): 7.96 (t, J ¼ 1.5 Hz, Ar H, 1H), 7.59–7.60 (m,
Ar H, 2H), 4.90 (br s, ANHA), 4.22 (d, J ¼ 5.5 Hz,
ACH2ANHA, 2H), and 1.48 (s, AC(CH3)3, 9H); 13C NMR
(300 MHz, CDCl3, d):146.8, 144.00, 143.2, 135.6, 94.9, 43.2,
and 28.4. MALDI DHB matrix (m/z) [MþNa]þ calcd for
mPPE1 and mPPE2
To a 25-mL round-bottomed flask (dried, then cooled under
N2, equiped with a magnetic stir bar, and immersed in an ice
bath) was added HCl 4 M/dioxane (2 mL). Later, a solution-
containing p_mPPE3 (or p_mPPE4; 10 mg in 3 mL of chloro-
C
12H15I2NO2Naþ 481.909; found, 483.496. LC–MS EI (70 Ev),
m/z (relative intensity): 401.18 (53), 383.28 (1.8), 356.33
(17), 341/43 (20), 275.18 (27), 257.39 (11), 231/68 (100),
and 215.92 (15). Anal. Calcd. for C12H15I2NO2 (459.065): C
31.40; H 3.29; N 3.05. Found: C 32.25; H 3.25; N 2.95.
ꢂ
form) was slowly added. The mixture was stirred at 0 C for
1 h; during that time, the clear yellow solution turned to a
milky solution, and yellow precipitate was observed. The yel-
low suspension was filtered; the solid was washed on the fil-
ter paper with diethyl ether (three times, 50 mL each). The
solid was dissolved in methanol (10 mL), concentrated, and
then reprecipitated by adding diethyl ether (50 mL). The
resulting mixture was filtered and washed with diethyl ether
to collect the final product as a pale yellow solid (7.5 mg).
p_mPPE1 and p_mPPE2
To a 25-mL round-bottomed flask (dried, then cooled under
N2, equipped with a magnetic stir bar) was added (chemical
(6) for p_mPPE3) or (chemical (7) for p_mPPE4) (100 mg),
(2) (66.5 mg, 1.0 equiv.), Pd2(dba)3 (3.8 mg, 0.02 equiv.), CuI
(1.6 mg, 0.04 equiv.), and P(Ph)3 (10.6 mg, 0.2 equiv.). The
flask was sealed, purged with N2, and evacuated (three
times) to remove any moisture. Then dried DIPA (0.8 mL)
and dried toluene (8.0 mL) were added using syringes. The
solution was heated to 78 ꢂC and stirred in an oil bath for
24 h. The final dark brownish yellow solution was filtered
through a short silica gel column to remove the catalyst,
eluted with 9/1 v/v chloroform/isopropanol to collect a
clear, yellow solution containing the polymer and monomers.
This solution was concentrated, and the polymer was sepa-
rated from the monomer by flash column chromatography,
where it was initially eluted with a 1:2 v/v hexane/ethyl ace-
tate solution and then with a 9:1 v/v chloroform/isopropa-
nol mixture. The polymer-containing fractions were concen-
trated, precipitated in hexane, then filtered, and washed with
hexane to collect the final polymer as a pale yellow solid.
Final recovery of p_mPPE3 and p_mPPE4 was 94.5 and 112
mg, respectively.
mPPE1
1H NMR (300 MHz, DMSO-d6, d): 8.54 (br s, ANH3þ), 8.02–
8.08 (br m, Ar H), 7.79–7.87 (br m, Ar H), 4.45 (br s,
ACOOCH2A), 4.18 (br s, AOCH3), 4.04 (br s, ACH2ANHA),
3.78–3.97 (br m, ACH2AOACH2A), 3.50–3.60 (br m,
ACH2AOACH2A), and 3.17 (s, AOCH3).
mPPE2
1H NMR (300 MHz, DMSO-d6, d): 8.62 (br s, ANH3þ), 7.83–
8.26 (br m, Ar H), 4.43 (br s, ACOOCH2A), 4.08–4.12 (br m,
ACH2ANHA), 3.77 (br s, ACH2AOACH2A), 3.50–3.62 (br m,
ACH2-OACH2A), and 3.18 (s, AOCH3).
2-(2-(2-Methoxyethoxy)ethoxy)ethyl
3,5-bis(phenylethynyl)benzoate
To a 25-mL round-bottomed flask (dried, then cooled under
N2, equipped with a magnetic stir bar) was added 2-(2-(2-
methoxyethoxy)ethoxy)ethyl 3,5-diiodobenzoate [chemical
(1), 200 mg, 0.38 mmol], ethynylbenzene (117.2 mg, 3.0
equiv.), Pd2(dba)3 (9.6 mg, 0.02 equiv.), CuI (4.0 mg, 0.04
equiv.), and (P(Ph)3) (27.2 mg, 0.2 equiv.). The flask was
sealed, purged with N2, and then evacuated (three times) to
remove any moisture. Dried DIPA (1.67 mL) and dried tolu-
ene (16.5 mL) were subsequently added using syringes. The
p_mPPE1
1H NMR (300 MHz, CDCl3, d): 8.19 (br s, Ar H), 7.88 (br s,
Ar H), 7.47 (br s, Ar H, 2H), 5.01 (br s, ANH), 4.53–4.56 (br
m, ACOOCH2), 4.23 (br s, ACH2ANHA), 4.19 (br s, AOCH3),
3.87–3.90 (br m, COOCH2ACH2AOA, 2H), 3.65–3.74 (br m,
AOACH2ACH2AOACH2ACH2AOACH3), 3.55–3.58 (br m,
ACH2AOACH3), 3.37 (br s, CH2AOACH3), and 1.49 (br s,
AC(CH3)3). GPC result: Mw ¼ 21735 Da, Mn ¼ 9622 Da, Mp
¼ 9481 Da, and polydispersity ¼ 2.26. Small amounts of
very high molecular weight polymer were also detected
(they were beyond the range of the polystyrene standards).
ꢂ
solution was stirred at 78 C in an oil bath for 24 h. The so-
lution was later cooled to room temperature and passed
through a short silica gel column (using ethyl acetate as the
eluent). Solvent was removed using a rotary vacuum evapo-
rator to collect crude product as yellow oil. The crude prod-
uct was later purified by flash column chromatography and
eluted with 1:2 v/v hexane/ethyl acetate to collect the final
product as a yellow oil. TLC (1:2 v/v hexane/ethyl acetate)
p_mPPE2
1H NMR (300 MHz, CDCl3, d): 8.13–8.15 (br m, Ar H), 7.80–
7.85 (br m, Ar H), 7.63 (br s, Ar H), 7.47 (br s, Ar H), 5.10
(br s, ANH), 4.52 (br s, ACOOCH2ꢁ), 4.35 (br s,
ACH2ANHA), 3.88 (br s, ACOOACH2ACH2AOA), 3.66–3.74
Rf ¼ 0.63. H NMR (300 MHz, CDCl3, d): 8.18 (d, J ¼ 1.4 Hz,
1
Ar H, 2H), 7.88 (m, J ¼ 1.4 Hz, Ar H, 2H), 7.55–7.59 (m, Ar
H, 4H), 7.38–7.40 (m, Ar H, 6H), 4.54 (t, J ¼ 4.7 Hz,
ACOOCH2A, 2H), 3.89 (t, J ¼ 4.7 Hz, ACOOCH2ACH2AOA,
2H), 3.67–3.75 (m, AOACH2ACH2AOACH2ACH2AOACH3,
(m,
AOACH2ACH2AOACH2ACH2AOACH3),
3.53–3.56
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