Macromolecules
Article
polarized continuum for dichloromethane solvent. The vibrational
frequencies for the optimized geometries were all positive, assuring
that the geometries are at least a local minimum. Single point energy
calculations were used to generate the molecular orbital diagrams
utilizing B3LYP/6-31G(d). Time-dependent density functional theory,
TD-B3LYP/6-311+G(d), was employed for estimates of the
ArH), 7.20 (s, 1H, 5″-ArH) 6.98 (s, 1H, −COCHCO−), 4.25 (t, J = 6,
2H, ArOCH CH OH), 4.06 (t, J = 6, 2H, ArOCH CH OH), 2.2 (s,
2
2
2
2
1H, ArOCH CH OH). HRMS (ESI, TOF) m/z calcd for C H O
335.1283 [M] ; found 335.1289.
2
2
21 19
4
+
1-[6-(2-Hydroxyethoxy)-2-naphthyl]-3-(4-bromophenyl)propane-
1,3-dione (b(Br)nmOH) (4). The BrPh-Np ligand was prepared as
4
3,44
1
absorption spectra, at the respective optimized geometries.
The
described for 5. A tan powder was obtained: 110 mg (14%). H NMR
first three excited states were computed for each compound. Molecular
(300 MHz, CDCl ): δ 16.96 (s, 1H, −OH), 8.48 (s, 1H, 1″-ArH), 8.00
3
45
orbitals were depicted by GaussView 5 software.
β-Diketonate Ligand Synthesis. 6-Hydroxy-2-acetonaptha-
(d, J = 8.7, 1H, 8″-ArH), 7.94−7.90 (m, 3H, 2′, 6′-ArH, 3″-ArH), 7.81
(d, J = 8.7, 1H, 4″-ArH), 7.64 (d, J = 8.7, 2H, 3′, 5′-ArH), 7.26 (d, J =
8.7,1H, 7″-ArH), 7.19 (s, 1H, 5″-ArH), 6.94 (s, 1H, COCHCO), 4.25
(t, J = 4.2, 2H, −ArOCH CH OH), 4.09−4.04 (m, 2H,
4
6
lene. The naphthyl precursor was prepared as previously described
with the following exceptions. 6-Methoxy-2-acetonapthalene (1.5 g,
.5 mmol) dissolved in 12 M HCl (500 mL) was heated at 90 °C for 2
h. The hot reaction mixture was filtered through a sintered glass frit
M) to remove a greenish-black precipitate. The filtrate was allowed to
2
2
7
−ArOCH
m/z calcd for C21
Boron Initiator Complexes. A representative preparation for
CH
2
2
OH), 2.05 (s, 1H, CH
2 2
CH OH). HRMS (ESI, TOF)
+
H O
18 4
Br 413.0388 [M + H] ; found 413.0376.
(
4
7
cool to room temperature, and then the flask was further cooled in an
ice water bath. The resulting white solid was collected by filtration and
was washed with copious quantities of distilled water until the pH of
the wash fraction was neutral (pH ∼ 6.5). (Note: in certain
preparations, when the sample was greenish or brownish in color,
further purification by recrystallization from hexane/EtOAc was
difluoroboron initiators is provided for complex 6 below.
16
BF
the literature. A yellow powder was obtained: 296 mg (84%). H NMR
(300 MHz, CDCl ): δ 8.76 (s, 1H, 2″-ArH), 8.21 (d, 2H, 2′,6′-ArH),
7.98 (m, 5H, 4″,7″,9″,10″-ArH, COCHCO), 7.68 (m, 2H, 5″,6″-ArH),
7.08 (d, 2H, 3′,5′-ArH), 4.23 (t, J = 4.2, 2H, −ArOCH CH OH), 4.05
(t, J = 4.2, 2H, −ArOCH CH OH). HRMS (ESI, TOF) m/z calcd
Na 405.1099 [M + Na] ; found 405.1094.
n(Br)bmOH (6). The ligand nbmOH, 2 (250.0 mg, 0.605
mmol), was added to a flame-dried two-neck round-bottom flask
under nitrogen and was dissolved in THF/CH Cl (20/20 mL) to give
nbmOH (5). The Np-Ph complex was prepared as described in
2
1
3
2
2
performed.) After drying in vacuo, a white powder was obtained:
2
2
1
+
1
.27 g (91%). H NMR (300 MHz, CDCl , ppm): δ 8.41 (s, 1H, 1-
C H16BO F
21 4 2
3
ArH), 8.00 (d, 1H, J = 8.7 Hz, 8-ArH), 7.89 (d, 1H, J = 9.0, 3-ArH),
BF
2
7
1
.72 (d, 1H, J = 9.0, 4-ArH), 7.20−7.16 (bm, 2H, 5, 7-ArH), 5.42 (s,
H, OH), 2.71 (s, 3H, CH ).
2
2
3
6
-(2-Hydroxy)ethoxy-2-acetonapthalene. 6-Hydroxy-2-acetonap-
a pale yellow solution. Boron trifluoride diethyl etherate (115 μL,
0.907 mmol) was added via syringe, and the solution turned bright
yellow. The reaction was stirred at room temperature for 48 h.
Solvents were removed via rotary evaporation, resulting in a yellow
solid. The crude material was purified by recrystallization in 1:1
EtOAc/acetone to yield a yellow-orange powder: 143 mg (53%). The
BrNp-Ph complex was prepared as described for 11. A yellow powder
thalene (515 mg, 2.8 mmol) was dissolved in DMF (100 mL) in
the presence of K CO (1.22 g, 8.8 mmol) and KI (50 mg, 0.3 mmol)
2
3
and was refluxed at 100 °C overnight (16 h). DMF was removed via
H O/CH Cl extraction (1 L of H O, 100 mL CH Cl ). The organic
2
2
2
2
2
2
layer was washed with H O (2 × 20 mL) and brine (2 × 20 mL) and
then was dried over Na SO , filtered, and concentrated via rotary
evaporation. The crude product was purified by column chromatog-
2
2
4
1
was obtained: 21 mg (37%). H NMR (300 MHz, DMSO): δ 9.07 (s,
raphy (3:1 hexanes/EtOAc) and dried in vacuo to yield a white
1H, 1″-ArH), 8.43−8.38 (bm, 4H, 3″,8″-ArH, 2′,6′-ArH), 8.18−8.11
(bm, 2H, 5″,7″-ArH), 7.98 (s, 1H, COCHCO), 7.81 (d, J = 9, 1H, 4″-
ArH), 7.23 (d, J = 9, 2H, 3′,5′-ArH), 4.98 (t, J = 5.4, 1H, −OH), 4.19
1
powder: 460 mg (72%). H NMR (300 MHz, CDCl , ppm): δ 8.40 (s,
3
1
7
H, 1-ArH), 8.02 (d, 1H, J = 9, 8-ArH), 7.88 (d, 1H, J = 9.0, 3-ArH),
.76 (d, 1H, J = 9, 4-ArH), 7.23 (d, 1H, J = 9, 7-ArH), 7.18 (s, 1H, 5-
(t, J = 4.8, 2H, −ArOCH
−ArOCH CH
BrNa 483.0191 [M + Na] ; found 483.0180.
bnmOH (7). The Ph-Np complex was prepared as described for
CH OH), 3.77 (t, J = 4.5, 2H,
2
2
ArH), 4.23 (t, J = 4.5, 2H, −ArOCH CH OH), 4.05 (t, J = 4.5, 2H,
2
OH). HRMS (ESI, TOF) m/z calcd
2
2
2
+
−
ArOCH CH OH), 2.06 (s, 1H, −OH).
C H16BO F
21 4 2
2
2
2
-(6-(2-((Tetrahydro-2H-pyran-2-yl)oxy)ethoxy)naphthalen-2-
BF
2
1
ylethanone. The ligand precursor was prepared as previously
6. A yellow powder was obtained: 154 mg (48%). H NMR (300
MHz, DMSO): δ 9.07 (s, 1H, 1″-ArH), 8.39 (d, J = 9, 2H, 2′,6′-ArH),
8.31 (d, J = 9, 1H, 8″-ArH), 8.13 (d, J = 9, 1H, 3″-ArH), 8.03−7.98
(m, 2H, 4′-ArH, COCHCO), 7.81 (d, J = 9, 1H, 7″-ArH), 7.68 (t, J =
6, 2H, 3′,5′-ArH), 7.50 (s, 1H, 5″-ArH), 7.34 (d, J = 9, 1H, 4″-ArH),
described using 6-(2-hydroxy)ethoxy-2-acetonapthalene instead of 1-
[
4-(2-hydroxyethoxy)phenyl]ethanone. The crude product was
purified by silica column chromatography (6:1 hexanes/EtOAc) to
1
give a tan solid: 1.12 g (68%). H NMR (300 MHz, CDCl , ppm): δ
3
8
.40 (s, 1H, 1-ArH), 8.00 (d, 1H, J = 9, 8-ArH), 7.86 (d, 1H, J = 9.0, 3-
5.00 (t, J = 6, 1H, OH), 4.18 (t, J = 6, 2H, −ArOCH
(t, J = 6, 2H, −ArOCH CH OH). HRMS (ESI, TOF) m/z calcd
383.1266 [M] ; found 383.1252.
b(Br)nmOH (8). The BrPh-Np complex was prepared as
2 2
CH OH), 3.80
ArH), 7.57 (d, 1H, J = 9.0, 4-ArH), 7.26 (d, 1H, J = 9.0, 7-ArH), 7.19
2
2
+
(
2
−
2
s, 1H, 5-ArH), 4.74 (t, 1H, J = 3.5,−O−CH* (CH −)O−), 4.31 (t,
C H18BO F
21 4 2
2
H, J = 4.5, −ArOCH CH OR), 3.92 (t, 2H, J = 4.2,
BF
2
2
2
1
ArOCH CH OR), 3.55 (t, 2H, J = 6, OCH −C H −CH (R)O−),
described for 6. A yellow powder was obtained: 41 mg (49%). H
NMR (300 MHz, DMSO): δ 9.07 (s, 1H, 1″-ArH), 8.32- 8.28 (m, 3H,
2′,6′-ArH, 8″-ArH), 8.13 (d, J = 9.0, 1H, 3″-ArH), 8.03−7.99 (m, 2H,
7″-ArH, COCHCO), 7.90 (d, J = 9, 2H, 3′,5′-ArH), 7.50 (s, 1H, 5″-
ArH), 7.32 (d, 1H, 4″-ArH), 5.0 (t, J = 6, 1H, −OH), 4.18 (t, J = 6,
2H, −ArOCH CH OH), 3.80 (t, J = 6, 2H, −ArOCH CH OH).
2
2
2
3
6
.70 (s, 3H, −CH ), 1.80−1.65 (bm, 6H, OCH −C H −CH (R)O−).
3
2
3
6
+
HRMS (ESI, TOF) m/z calcd for C H O 315.1596 [M] ; found
19
23
4
3
15.1596.
-[4-(2-Hydroxyethoxy)phenyl]-3-(6-bromo-2-naphthyl)propane-
,3-dione (n(Br)bmOH) (2). The BrNp-Ph ligand was prepared as
1
1
2
2
2
2
described for 5. A cream colored powder was obtained: 520 mg (59%).
HRMS (ESI, TOF) m/z calcd C H BO F BrNa 483.0191 [M +
21 16 4 2
1
+
H NMR (300 MHz, CDCl ): δ 17.03 (s, 1H, −OH), 8.49 (s, 1H, 1″-
Na] ; found 483.0193.
3
ArH) 8.10−7.90 (m, 4H, 2′,6′-ArH, 3″,5″-ArH,), 7.88−7.71 (m, 2H,
7
ArH), 6.93 (s, 1H, COCHCO), 4.19 (t, J = 4.2, −ArOCH CH OH),
4
Boron Polymer Synthesis. Preparative scale reactions were
conducted as follows. The boron initiator and D,L-lactide were placed
″,8″-ArH), 7.63 (d, J = 9, 1H, 3″-ArH), 7.03 (d, J = 9, 2H, 3′, 5′-
in a Kontes flask and sealed under N
entirely submerged in an oil bath at 130 °C. After the D,L-lactide
melted, Sn(Oct) in hexanes was added, and the reaction was heated
. The bulb of the flask was
2
2
2
.03 (m, 2H, −ArOCH CH OH), 3.48 (s, 1H, CH CH OH). HRMS
2
2
2
2
+
(
ESI, TOF) m/z calcd for C H O Br 413.0388 [M + H] ; found
2
21
18
4
4
13.0401.
-[6-(2-Hydroxyethoxy)-2-naphthyl]-3-phenylpropane-1,3-dione
bnmOH) (3). The Ph-Np ligand was prepared as described for 5. A
for the designated time (∼1−3 h). (See Table S1 for reagent loadings
and reaction times for specific samples.) Crude polymer was purified
by precipitation from CH Cl /cold MeOH (−20 °C). The polymer
1
(
2
2
1
white powder was obtained: 154 mg (48%). H NMR (300 MHz,
was collected by centrifugation, the filtrate was decanted, and the
CDCl ): δ 17.02 (s, 1H, −OH), 8.49 (s, 1H, 1″-ArH), 8.06−7.99 (bm,
rubbery solid was redissolved in CH Cl and reprecipitated in cold
3
2
2
3
H, 8″-ArH, 2′,6′-ArH) 7.90 (d, J = 9, 1H, 3″-ArH) 7.81 (d, J = 9, 1H,
″-ArH), 7.57−7.51 (bm, 3H, 3′,4′,5′-ArH), 7.25 (d, J = 9, 1H, 7″-
MeOH (−20 °C). The resulting solid was reprecipitated from
4
CH Cl /hexanes, collected by centrifugation, the filtrate was decanted,
2
2
C
dx.doi.org/10.1021/ma5006606 | Macromolecules XXXX, XXX, XXX−XXX