SUPPORTING INFORMATION
Stereoregular Polycarbonate Synthesis: Alternating Copolymerization of
CO2 with Aliphatic Terminal Epoxides Catalyzed by Multi-chiral Cobalt(III)
Complexes
Wei-Min Ren, Ye Liu, Guang-Peng Wu, Jie Liu, and Xiao-Bing Lu*
State key laboratory of fine chemicals, Dalian University of Technology, Dalian 116012, China.
Contents
1. General information
2. Synthesis of (S)-3-formyl-2-hydroxy-2’-alkyloxy-1,1’-binaphthyl
3. Synthesis of 3-(3-(1-adamanyl)-4-methoxyphenyl)propan-1-ol (A)
4. Degradation of poly(propylene carbonate)s and determination of enantiomeric purity of cyclic
propylene carbonate
5. 1H NMR and 13C NMR spectra of the ligand (S,S,S)-L1c
6. The carbonyl region of the 13C NMR spectra of various aliphatic polycarbonates obtained with 1c
S1
1. General Information
All manipulations involving air- and/or water-sensitive compounds were carried out in standard
glove box or under dry nitrogen using standard Schlenk techniques. Propylene oxide was purchased
from Acros company and distilled under a nitrogen atmosphere from CaH2 prior to use.
(R)-Propylene oxide was produced by the classic method of hydrolytic kinetic resolution of racemic
propylene oxide using (R)-SalenCo(III)OAc.
NMR Experiments. 1H and
13
C NMR spectra were recorded on Varian INOVA-400 MHz type
(1H, 400 MHz), and a Bruker 500 MHz type (13C, 125 MHz) spectrometer, respectively. Their peak
freguencies were referenced versus an internal standard (TMS) shifts at 0 ppm for 1H NMR and
against the solvent, chloroform-d at 77.0 ppm for 13C NMR, respectively.
Mass Spectrometry. A Micromass Q-Tof (Micromass, Wythenshawe, UK) mass spectrometer
equipped with an orthogonal electrospray source (Z-spray) used for the cobalt complexes in positive
ion mode(Capillary = 2000 V, Sample cone = 20 V).
Size Exclusion Chromatograph. Polymer molecular-weight analysis was carried out by Size
Exclusion Chromatograph (SEC) on a Viscotek TDA 302 with refractive index, laser light scattering,
and viscosity detectors. PL gel 2 × 300 mm 5-μm mixed-C columns were employed, and
tetrahydrofuran used as eluent with a flow rate of 1.00 mL/min at 30 °C. The sample concentration
was 5.0 mg/mL, and the injection volume was 100 μl. The curve was calibrated using monodisperse
polystyrene standards covering the molecular weight rage from 580 to 460000 Da.
2. Synthesis of (S)-3-formyl-2-hydroxy-2’-alkyloxy-1,1’-binaphthyl
CHO
OH
OH
5
i
O
OH
O
ii
O
OR
6
O
iii
O
OR
7
O
8
iv
a: R = Me
b: R = nBu
c : R = i Pr
CHO
OH
OR
(i): MOMCl; (ii): RI; (iii): n BuLi, DMF; (iv): conc. HCl.
9
(S)-2-methoxymethoxy-2’-hydroxy-1,1’-binaphthyl (6): To a 500 mL three-necked flask
equipped with a magnetic stir bar, THF (150 mL) and NaH (4.6 g, 0.20 mol) were added. When the
S2
mixture was cooled down to 0 oC, a solution of (S)-BINOL (5) (28.6 g, 0.10 mol) in 50 mL THF was
added dropwise. After 1 h additional stirring, methoxymethyl chloride (MOMCl) (13.0 g, 0.15 mol)
was added by a syringe. The reaction was then continued for another 4 h at room temperature and
then quenched with 100 mL water. This mixture was extracted with ethyl acetate (3 × 100 mL). The
combined organic phase was washed with brine, and dried over MgSO4. Removal of solvent
followed by column chromatography on silica gel using petrol ether/ethyl acetate (5/1) as the mobile
phase to give the afforded (S)-2-methoxymethoxy-2’-hydroxy-1,1’-binaphthyl (6) (24.5 g, 74%). 'H
NMR (400 MHz, CDCl3): δ 8.02 (d, J = 8.8 Hz, 1H), 7.90 (d, J = 8.8 Hz, 2H), 7.85 (d, J = 8.8 Hz,
1H), 7.59 (d, J = 8.8 Hz, 1H), 7.40 (t, J = 8.8 Hz, 1H), 7.24–7.36 (m, 4H), 7.20 (t, J = 8.4 Hz, 1H),
7.07 (d, J = 8.4 Hz, 1H), 5.10 (d, J = 8.4 Hz, 1H), 5.05 (d, J = 8.4 Hz, 1H), 4.97 (br, 1H), 3.18 (s,
3H).
General procedure for the synthesis of (S)-2-methoxymethoxy-2’-alkoxy-1,1’-binaphthyl (7):
K2CO3 (5.6 g, 0.04 mol) and alkyl iodide (0.03 mol) were added to a solution of compound 6 (6.6 g,
0.02 mol) in DMF (100 mL). After it was stirred for 20 h at room temperature, 200 mL of 0.5 M
NaOH (aq) was added to the solution and the reaction mixture was extracted with diethyl ether (3 ×
150 mL) and washed with brine, and dried. Removal of solvent followed by column chromatography
on silica gel using petrol ether/ethyl acetate (10/1) as the mobile phase to give the afforded
(S)-2-methoxymethoxy-2’-alkoxy-1,1’- binaphthyl (7).
(S)-2-methoxymethoxy-2’-methoxy-1,1’-binaphthyl (7a): (6.5 g, 94%). 'H NMR (400 MHz,
CDCl3): δ 7.97 (d, J = 8.8 Hz, 1H), 7.94 (d, J = 8.8 Hz, 1H), 7.86 (d, J = 8.8 Hz, 1H), 7.85 (d, J =
8.8 Hz, 1H), 7.56 (d, J = 8.8 Hz, 1H), 7.44 (t, J = 8.8 Hz, 1H), 7.28–7.35 (m, 2H), 7.18–7.23 (m, 2H),
7.11–7.13 (m, 2H), 5.06 (d, J = 6.8 Hz, 1H), 4.98 (d, J = 6.8 Hz, 1H), 3.76 (s, 3H), 3.15 (s, 3H).
(S)-2-methoxymethoxy-2’-butoxy-1,1’-binaphthyl (7b): (6.1 g, 88%). 'H NMR (400 MHz,
CDCl3): δ 7.93 (d, J = 8.4 Hz, 1H), 7.92 (d, J = 8.4 Hz, 1H), 7.85 (d, J = 8.4 Hz, 2H), 7.55 (d, J =
8.4 Hz, 1H), 7.42 (d, J = 8.4 Hz, 1H), 7.28–7.35 (m, 2H), 7.11–7.23 (m, 4H), 5.07 (d, J = 6.8 Hz,
1H), 4.95 (d, J = 6.8 Hz, 1H), 3.95–4.05 (m, 2H), 3.15 (s, 3H), 1.27–1.40 (m, 2H), 0.91–0.98 (m,
2H), 0.63 (t, J = 7.2 Hz, 3H).
(S)-2-methoxymethoxy-2’-isopropoxy-1,1’-binaphthyl (7c): (6.3 g, 91%). 'H NMR (400 MHz,
CDCl3): δ 7.95 (d, J = 8.4 Hz, 1H), 7.92 (d, J = 8.4 Hz, 1H), 7.85 (d, J = 8.4 Hz, 1H), 7.83 (d, J =
8.4 Hz, 1H), 7.56 (d, J = 8.8 Hz, 1H), 7.45 (t, J = 8.8 Hz, 1H), 7.26–7.33 (m, 2H), 7.20–7.24 (m, 2H),
7.10–7.15 (m, 2H), 5.08 (d, J = 7.2 Hz, 1H), 4.96 (d, J = 7.2 Hz, 1H), 4.50–4.54 (m, 1H), 3.11 (s,
3H), 1.19 (d, J = 6.0 Hz, 3H), 0.93 (d, J = 6.0 Hz, 3H).
General
procedure
for
the
synthesis
of
(S)-3-formyl-2-methoxymethoxy-2’-
alkoxy-1,1’-binaphthyl (8): To a solution of compound 7 (0.01 mol) in THF (50 mL), 1.6 M BuLi
(7.3 mL, 0.012 mol) was added within 15 min at –78 oC under argon. The mixture was warmed up to
0 oC and stirred for 30 min and then cooled down to –78 oC. A solution of DMF (1.6 mL, 0.02 mol)
S3
in THF (10 mL) was added dropwise. This reaction was carried out at –78 oC for 30 min and then at
0 oC for 40 min. The obtained yellow solution was quenched with 50 mL saturated NH4Cl solution
and then with 50 mL 1 M HCl solution. After separating the organic layer, the water layer was
extracted with ethyl ether (3 ×50 mL). The combined organic layer was washed with saturated
NaHCO3 and brine, and dried over Na2SO4. Removal of solvent followed by column
chromatography on silica gel using petrol ether/ethyl acetate (5/1) as the mobile phase to give the
afforded (S)-3-formyl-2-methoxymethoxy-2’- alkoxy-1,1’-binaphthyl (8).
(S)-3-formyl-2-methoxymethoxy-2’-methoxy-1,1’-binaphthyl (8a): (2.3 g, 64%). 'H NMR (400
MHz, CDCl3): δ 10.59 (s, 1H), 8.04 (d, J = 8.8 Hz, 1H), 8.03 (d, J = 8.4 Hz, 1H), 7.90 (d, J = 8.4 Hz,
1H), 7.44–7.48 (m, 2H), 7.34–7.37 (m, 2H), 7.29 (d, J = 8.4 Hz, 1H), 7.20 (d, J = 8.4 Hz, 1H), 7.12
(d, J = 8.4 Hz, 1H), 4.85 (d, J = 6.8 Hz, 1H), 4.62 (d, J = 6.8 Hz, 1H), 3.81 (s, 3H), 3.02 (s, 3H).
(S)-3-formyl-2-methoxymethoxy-2’-butoxy-1,1’-binaphthyl (8b): (2.1 g, 61%). 'H NMR (400
MHz, CDCl3): δ 10.47 (s, 1H), 8.05 (d, J = 8.0 Hz, 1H), 8.04 (d, J = 8.0 Hz, 1H), 7.91 (d, J = 8.4 Hz,
1H), 7.44–7.49 (m, 2H), 7.35–7.38 (m, 2H), 7.29 (d, J = 8.0 Hz, 1H), 7.21 (d, J = 8.4 Hz, 1H), 7.14
(d, J = 8.4 Hz, 1H), 4.86 (d, J = 6.8 Hz, 1H), 4.64 (d, J = 6.8 Hz, 1H), 3.95–4.05 (m, 2H), 3.12 (s,
3H), 1.37–1.45 (m, 2H), 0.95–1.00 (m, 2H), 0.65 (t, J = 7.6 Hz, 3H).
(S)-3-formyl-2-methoxymethoxy-2’-isopropoxy-1,1’-binaphthyl (8c): (2.1 g, 59%). 'H NMR
(400 MHz, CDCl3): δ 10.60 (s, 1H), 8.04 (d, J = 8.4 Hz, 1H), 8.03 (d, J = 8.4 Hz, 1H), 7.92 (d, J =
8.4 Hz, 1H), 7.45–7.49 (m, 2H), 7.35–7.38 (m, 2H), 7.30 (d, J = 8.4 Hz, 1H), 7.21 (d, J = 8.4 Hz,
1H), 7.12 (d, J = 8.4 Hz, 1H), 4.85 (d, J = 6.8 Hz, 1H), 4.63 (d, J = 6.8 Hz, 1H), 4.52–4.55 (m, 1H),
3.10 (s, 3H), 1.19 (d, J = 6.0 Hz, 3H), 0.92 (d, J = 6.0 Hz, 3H).
General procedure for the synthesis of (S)-3-formyl-2-hydroxy-2’-alkoxy-1,1’- binaphthyl
(9): To a solution of compound 8 (5.0 mmol) in 10 mL THF, 50 mL concentrated HCl was added
dropwise at 0 oC. This mixture was then stirred 3 h at room temperature and then extracted with
ethyl acetate. The obtained solution was washed with water, saturated NaHCO3 and brine, and dried
with
Na2SO4.
Removal
of
solvent
give
the
afforded
(S)-3-formyl-2-hydroxy-2’-alkoxy-1,1’-binaphthyl (9).
(S)-3-formyl-2-hydroxy-2’-methoxy-1,1’-binaphthyl (9a): (1.4 g, 88%). 'H NMR (400 MHz,
CDCl3): δ 10.44 (s, 1H), 10.18 (s, 1H), 8.30 (s, 1H), 8.00 (d, J = 8.0 Hz, 1H), 7.96 (d, J = 8.4 Hz,
1H), 7.88 (d, J = 8.4 Hz, 1H), 7.48 (d, J = 8.4 Hz, 1H), 7.31–7.39 (m, 3H), 7.26 (t, J = 8.4 Hz, 1H),
7.12–7.17 (m, 2H), 3.80 (s, 3H). HRMS (m/z) Calcd. for [C22H17O3]+: 329.1099, found: 329.1106.
(S)-3-formyl-2-hydroxy-2’-butoxy-1,1’-binaphthyl (9b): (1.5 g, 91%). 'H NMR (400 MHz,
CDCl3): δ 10.40 (s, 1H), 10.20 (s, 1H), 8.30 (s, 1H), 7.98 (d, J = 8.0 Hz, 1H), 7.96 (d, J = 8.4 Hz,
1H), 7.87 (d, J = 8.4 Hz, 1H), 7.44 (d, J = 8.4 Hz, 1H), 7.32–7.38 (m, 3H), 7.26 (t, J = 8.4 Hz, 1H),
7.16–7.18 (m, 2H), 3.95–4.05 (m, 2H), 1.37–1.45 (m, 2H), 0.95–1.00 (m, 2H), 0.65 (t, J = 7.6 Hz,
3H). HRMS (m/z) Calcd. for [C25H23O3]+: 371.1647, found: 371.1681.
S4
(S)-3-formyl-2-hydroxy-2’-isopropoxy-1,1’-binaphthyl (9c): (1.6 g, 94%). 'H NMR (400 MHz,
CDCl3): δ 10.42 (s, 1H), 10.16 (s, 1H), 8.30 (s, 1H), 8.01 (d, J = 8.0 Hz, 1H), 7.98 (d, J = 8.4 Hz,
1H), 7.87 (d, J = 8.4 Hz, 1H), 7.45 (d, J = 8.4 Hz, 1H), 7.33–7.39 (m, 3H), 7.26 (t, J = 8.4 Hz, 1H),
7.13–7.19 (m, 2H), 4.55–4.58 (m, 1H), 1.17 (d, J = 6.0 Hz, 3H), 0.91 (d, J = 6.0 Hz, 3H). HRMS
(m/z) Calcd. for [C24H21O3]+: 357.1491, found: 357.1487.
3. Synthesis of 3-(3-(1-adamanyl)-4-methoxyphenyl)propan-1-ol (A)
i
HO
CHO
ii
HO
iii
CHO
O
CHO
O
OH
O
F
G
H
I
iv
O
OH
v
O
OH
O
A
J
(i): 1-adamantanol, conc. H 2SO4 ; (ii): CH 3I; (iii): CH2 (COOH)2 , piperidine; (iv): H 2, Pd/C (10%); (v): LiAlH4.
3-(1-adamanyl)-4-hydroxybenzaldehyde (G): To a 500 mL round-bottomed flask is added
4-hydroxybenzaldehyde (F) (12.2 g, 0.12 mol), 1-adamantanol (16.7 g, 0.13 mol) and CH2Cl2 (300
mL). The solution is stirred and concentrated H2SO4 (18 M, 6.7 mL) is added dropwise over 20 min.
The biphasic mixture is allowed to stir for 48 h and H2O (100 mL) is added. The mixture is
neutralized slowly to pH = 9 by addition of a NaOH (2M). The mixture is extracted with CH2Cl2 (3
× 200 mL). The combined organics are washed with brine (150 mL), dried with Na2SO4. Removal of
solvent followed by column chromatography on silica gel using petrol ether/ethyl acetate (3/1) as the
mobile phase to give the afforded 3-(1-adamanyl)-4-hydroxybenzaldehyde (G) (23.4 g, 91%). 'H
NMR (400 MHz, CDCl3): δ 11.21 (s, 1H), 10.03 (s, 1H), 7.76 (s, 1H), 7.45 (d, J = 8.0, 1H), 6.92 (d,
J = 8.0, 1H), 2.05 (s, 6H), 2.01 (s, 3H), 1.73 (s, 6H).
3-(1-adamanyl)-4-methoxybenzaldehyde (H): A mixture of G (16.0 g, 0.063 mol), iodomethane
(4.8 mL, 0.076 mol) and K2CO3 (10.5 g, 0.076 mol) in acetonitrile (200 mL) was stirred for 24 h at
80 oC before it was allowed to reach ambient temperature, then filtered. The filtrate was evaporated
andthe residue was purified by column chromatography on silica gel using petrol ether/ethyl acetate
(3/1) as the mobile phase to give the afforded 3-(1-adamanyl)-4-methoxybenzaldehyde (H) (15.4 g,
92%). 'H NMR (400 MHz, CDCl3): δ 9.84 (s, 1H), 7.73 (s, 1H), 7.42 (d, J = 8.0, 1H), 6.84 (d, J =
8.0, 1H), 3.80 (s, 3H), 2.05 (s, 6H), 2.01 (s, 3H), 1.73 (s, 6H).
S5
3-(3-(1-adamanyl)-4-methoxyphenyl)acrylic acid (I): A well-stirred mixture of H (15.0 g, 0.055
mol), malonic acid (11.3 g, 0.11 mol), and piperidine (1.2 mL) in pyridine (70 mL) was heated for 2
h at 85 oC and then refluxed for 2 h. The mixture was cooled and poured with stirring into an excess
of cold 1N HCl (300 mL). The flocculent white precipitate was collected by suction filtration and
washed by resuspension. After stirring for 15 min in cold H2O (30 mL), the precipitate was collected
by
suction
filtration
and
dried.
The
yield
was
14.3
g
(83%)
of
3-(3-(1-adamanyl)-4-methoxyphenyl)acrylic acid (I). 'H NMR (400 MHz, CDCl3): δ 8.11 (d, J =
16.0 Hz, 1H), 7.64 (s, 1H), 7.43 (d, J = 8.8 Hz, 1H), 6.87 (d, J = 8.8 Hz, 1H), 6.49 (d, J = 16.0 Hz,
1H), 3.82 (s, 3H), 2.05 (s, 6H), 2.02 (s, 3H), 1.75 (s, 6H). HRMS (m/z) Calcd. for [C20H23O3]–:
311.1647, found: 311.1676.
3-(3-(1-adamanyl)-4-methoxyphenyl)propanoic acid (J): Compound I (8.0 g, 0.026 mol) was
taken up into THF (80 mL) and hydrogenated over 10% Pd-C (0.64 g) in an autoclave under a H2
pressure of 5.0 atm for 2 h. The reduction mixture was filtered and the solvent was evaporated in
vacuo to yield 3-(3-(1-adamanyl)-4-methoxyphenyl)propanoic acid (J) as a while solid (8.0 g, 99%).
'H NMR (400 MHz, CDCl3): δ 7.01 (s, 1H), 6.97 (d, J = 8.4 Hz, 1H), 6.76 (d, J = 8.4 Hz, 1H), 3.77
(s, 3H), 2.87 (t, J = 8.0 Hz, 2H), 2.62 (t, J = 8.0 Hz, 2H), 2.06 (s, 6H), 2.01 (s, 3H), 1.74 (s, 6H).
HRMS (m/z) Calcd. for [C20H25O3]–: 313.1804, found: 313.1817.
3-(3-(1-adamanyl)-4-methoxyphenyl)propan-1-ol (A): To a solution of LiAlH4 (1.5 g, 0.039
mol) in THF (40 mL) was added slowly a solution of J (5.0 g, 0.016 mmol) in THF (20 mL). When
the addition was completed, the reaction mixture was refluxed for 12 h. The reaction was quenched
by cautious addition of water (10 mL), the resultant insoluble was then filtered off, and the filtrate
was extracted with ethyl acetate (3 × 50 mL). The combined organic layers were dried (Na 2SO4),
filtered and reduced in vacuo to afford 3-(3-(1-adamanyl)-4-methoxyphenyl)propan-1-ol (A) as a
white solid (4.1 g, 85%). 1H NMR (400 MHz, CDCl3): δ 7.04 (s, 1H), 6.99 (d, J = 8.4 Hz, 1H), 6.79
(d, J = 8.4 Hz, 1H), 3.81 (s, 3H), 3.69 (t, J = 7.4 Hz, 2H), 2.64 (t, J = 7.4 Hz, 2H), 2.09 (s, 6H), 2.06
(s, 3H), 1.77 (s, 6H). HRMS (m/z) Calcd. for [C20H29O2]+: 301.2168, found: 301.2179.
4. Degradation of PPC and determination of enantiomeric purity of cyclic propylene
carbonate.
To a stirred mixture of poly(propylene carbonate) (0.5 g) in tetrahydrofuran (25 mL) was added
LiOtBu (25 mg) in tBuOH of 1 mL. The solution was stirred under a dry nitrogen atmosphere at 40
C for 24 h. The product was analyzed by 1H NMR method. The enantiomeric excesses (ee’s) of the
o
resulting cyclic propylene carbonate was further determined by chiral GC analysis (GC column,
2,6-dibutyl-3-butyryl-β-Cyclodex, 30 m×0.25 mm id ×0.25 μm film; injecton temp. = 250 °C;
detection temp. = 250 °C; 160 °C, isothermal, tR[(R)-PC] = 7.83 min, tR[(S)-PC] = 8.02 min) using a
Agilent Technologies 6890 Gas Chromatograph with N2 as a carry gas.
S6
5. 1H NMR and 13C NMR spectra of the ligand (S,S,S)-L1c
N
N
OH
HO
N
N
N
O
13.50 13.00
ppm (f1)
ppm (f1) 8.0
7.0
6.0
5.0
4.0
3.0
2.0
Figure S1. 1H NMR spectrum of ligand (S,S,S)- L1c
150
ppm (f1)
100
50
Figure S2. 13C NMR spectrum of ligand (S,S,S)-L1c
S7
1.0
6. The carbonyl region of the 13C NMR spectra of various aliphatic polycarbonates
obtained with 1c
A
B
ppm (f1)
155.00
154.50
13
Figure S3. The carbonyl region of the C NMR spectra of various aliphatic polycarbonates obtained
with 1c: (A) poly(1,2-butene carbonate); (B) poly(1,2-hexene carbonate).
S8