Synthesis, crystal structure and photophysical properties of pyrene-helicene hybrids

Article abstract of DOI:10.1002/chem.201301431

Synthesis of helically chiral aromatics resulting from fusion of pyrene and [4]- or [5]helicene has been accomplished using photoredox catalysis employing a Cu-based sensitizer as the key step. Photocyclisation experiments for the synthesis of the target

Full text of DOI:10.1002/chem.201301431

Supporting Information
ꢀ Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2013
Synthesis, Crystal Structure and Photophysical Properties of
Pyrene–Helicene Hybrids
Anne-Catherine Bꢀdard,[a] Anna Vlassova,[a] Augusto C. Hernandez-Perez,[a]
Andrꢀ Bessette,[a] Garry S. Hanan,[a] Matthew A. Heuft,[b] and Shawn K. Collins*[a]
chem_201301431_sm_miscellaneous_information.pdf

Synthesis, Crystal Structure and Photophysical
Properties of Pyrene/Helicene Hybrids
Anne-Catherine Bédard,† Anna Vlassova,† Augusto C. Hernandez-Perez,† André
Bessette,† Garry S. Hanan,† Matthew A. Heuft‡, and Shawn K. Collins†*
† Département de Chimie, Centre for Green Chemistry and Catalysis, Université de Montréal, CP 6128
Station Downtown, Montréal, Québec, CANADA H3C 3J7 ‡Xerox Research Centre of Canada, Xerox
Corporation, 2660 Speakman Dr., Mississauga, ON L5K 2L1
SUPPORTING INFORMATION
TABLE OF CONTENTS:
GENERAL
SYNTHETIC PROCEDURES
UV-VIS DATA
S2
S3
S16
S17
S18
S20
FLUORESCENCE DATA
HOMO/LUMO REPRESENTATIONS
SPECTRAL DATA
S1

General:
All reactions that were carried out under anhydrous conditions were performed under an
inert argon or nitrogen atmosphere in glassware that had previously been dried overnight
o
at 120 C or had been flame dried and cooled under a stream of argon or nitrogen.1 All
chemical products were obtained from Sigma-Aldrich Chemical Company or Strem
Chemicals and were reagent quality. Technical solvents were obtained from VWR
International Co. Trimethoxybenzaldehyde2 and (2,7-di-(tert-butyl)pyren-4-yl)-4,4,5,5-
tetramethyl-1,3,2-dioxaborolane3 were prepared according to literature procedure.
Anhydrous solvents (CH2Cl2, Et2O, THF, DMF, toluene, and n-hexane) were dried and
deoxygenated using a GlassContour system (Irvine, CA). Isolated yields reflect the mass
obtained following flash column silica gel chromatography. Organic compounds were
purified using the method reported by W. C. Still4 and using silica gel obtained from
Silicycle Chemical division (40-63 nm; 230-240 mesh). Analytical thin-layer
chromatography (TLC) was performed on glass-backed silica gel 60 coated with a
fluorescence indicator (Silicycle Chemical division, 0.25 mm, F254.). Visualization of
TLC plate was performed by UV (254 nm), KMnO4 or p-anisaldehyde stains. All mixed
solvent eluents are reported as v/v solutions. Concentration refers to removal of volatiles
at low pressure on a rotary evaporator. All reported compounds were homogeneous by
1
thin layer chromatography (TLC) and by H NMR. NMR spectra were taken in
deuterated CDCl3 using Bruker AV-300 and AV-400 instruments unless otherwise noted.
Signals due to the solvent served as the internal standard (CHCl3: δ 7.27 for 1H, δ 77.0 for
1
13C). The acquisition parameters are shown on all spectra. The H NMR chemical shifts
and coupling constants were determined assuming first-order behavior. Multiplicity is
indicated by one or more of the following: s (singlet), d (doublet), t (triplet), q (quartet),
m (multiplet), br (broad); the list of couplings constants (J) corresponds to the order of
the multiplicity assignment. High resolution mass spectroscopy (HRMS) was done by the
Centre régional de spectrométrie de masse at the Département de Chimie, Université de
Montréal from an Agilent LC-MSD TOF system using ESI mode of ionization unless
otherwise noted. Quantum-chemical calculations were performed using the Gaussian 03
program.5
1 Shriver, D. F.; Drezdon, M. A. in The Manipulation of Air-Sensitive Compounds; Wiley-VCH: New York, 1986.
2 Bois-Choussy, M.; Zhu, J.; J. Org. Chem. 1998, 63, 5662-5665.
3 Liu, Z.; Wang, Y.; Chen, Y.; Liu, J.; Fang, Q.; Kleeberg, C.; Marder, T. B. J. Org. Chem., 2012, 77, 7124–7128.
4 Still, W. C.; Kahn, M.; Mitra, A. J. Org. Chem. 1978, 43, 2923-2925.
5 Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A.;
Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.;
Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.;
Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.;
Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli,
C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.;
Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J.
B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.;
Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Laham, A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P.
M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez C.; Pople, J. A. Gaussian 03, Revision C.02, 2003.
S2

SYNTHETIC PROCEDURES
2-tert-Butylpyrene (4)6: Pyrene (5.0 g, 24.5 mmol, 1.0 equiv.) was dissolved in
dichloromethane (35 mL, 0.7 M) in a round bottom flask equipped with a stir bar. tert-
BuCl (3.5 mL, 31 mmol, 1.3 equiv.) was added to the solution and the reaction mixture
cooled to 0oC. AlCl3 (3.6 g, 27 mmol, 1.1 equiv.) was then added in portions and the dark
brown slurry was allowed to stir for 3 h, while gradually warming to room temperature.
The reaction was quenched by pouring the mixture into an erlenmyer flask filled with ice
water. Dichloromethane was added and the phases separated. The aqueous phase was
washed with dichloromethane (3X) and the combined organic extracts were washed with
brine and dried over Na2SO4. Following filtration through a Fisherbrand P8-creped coarse
filter paper, the filtrate was concentrated under reduced pressure and then dissolved in a
minimal amount of boiling methanol (~500 mL). The solution was cooled to room
temperature and then put in the freezer overnight. The precipitate was filtered off and the
2,7-di-tert-butylpyrene was obtained as a light brown solid (847 mg, 11%). The mother
liquor was concentrated under reduced pressure and dissolved in a minimal amount of
boiling hexanes (~20 mL). The mixture was left to re-crystallize overnight in the freezer.
Filtration offered the desired product 4 as a white solid (2.53 g, 40% yield). Additional
re-crystallizations may be done on the mother liquor to obtain more of 4. For 2,7-di-tert-
butylpyrene: 1H NMR (400MHz, CDCl3) δ ppm 8.19 (s, 4H), 8.03 (s, 4H), 1.59 (s, 18H);
13C NMR (75 MHz, CDCl3) δ ppm 148.7, 130.9, 127.6, 123.0, 122.1, 35.4, 32.1; HRMS
(ESI+) for C24H27 [M + H]+ calculated: 314.2029 found: 314.2028. For 2-tert-
1
butylpyrene: H NMR (400MHz, CDCl3) δ ppm 8.22 (s, 2H) 8.15 (d, J = 8.0 Hz, 2H),
8.06 (s, 4H), 7.97 (t, J = 8.0 Hz, 1H), 1.59 (s, 9H), 1.54 (s, H2O); 13C NMR (75 MHz,
CDCl3) δ ppm 149.2, 131.1, 127.7, 127.4, 125.6, 124.9, 123.1, 122.4, 35.4, 32.1; HRMS
(ESI+) for C20H19 [M + H]+ calculated: 258.1403 found: 258.1398
6 Miura, Y.; Yamano, E.; Tanaka, A. J. Org. Chem. 1994, 59, 3294-3300.
S3

2-(7-(tert-butyl)pyren-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
(5):7
2-tert-
Butyl-pyrene (750 mg, 2.9 mmol, 1 equiv.), B2pin2 (810 mg, 3.19 mmol, 1.1 equiv.), 4,4-
di-tert-butyl-2,2-bipyridine (dtbpy) (78 mg, 0.29 mmol, 10 mol %) and dry cyclohexane
(7.3 mL, 0.4 M) were added to a dry round bottom flask under N2. The catalyst
[Ir(COD)(OMe)2] (96.1 mg, 0.151 mmol, 5 mol %) was then added and the reaction set
to 70–80 oC for 18–72 h (slightly better yields were observed with longer reaction times).
The reaction mixture was concentrated under reduced pressure and purified by flash
column chromatography (100 % hexanes to 75 % dichloromethane/hexanes) to afford 5
as a yellow solid (612 mg, 55 % yield). 1H NMR (400 MHz, CDCl3) δ ppm 8.60 (s, 2H),
8.20 (s, 2H), 8.08 (d, J = 12.0 Hz, 2H), 8.03 (d, J = 8.0 Hz, 2H) 1.58 (s, 9H), 1.46 (s,
12H); 13C NMR (75 MHz, CDCl3) δ ppm 149.7, 131.6, 131.3, 130.4, 127.8, 127.6, 126.5,
123.0, 122.2, 84.2, 35.4, 32.1, 25.2; HRMS (ESI+) for C26H30BO2 [M + H]+ calculated:
385.2333 found: 385.2340
2-Bromo-7-(tert-butyl)pyrene (6):8 2-(7-(tert-butyl)pyren-2-yl)-4,4,5,5-tetramethyl-
1,3,2-dioxaborolane (1.0 g, 2.6 mmol, 1 equiv.) and dry methanol (33 mL, 0.08 M) were
o
added to a dry round bottom flask. The reaction mixture was heated to 80 C to fully
dissolve 5 and then CuBr2 (1.7 g, 7.8 mmol, 3 equiv.) was added. The reaction was left to
o
stir for 24–72 h at 80 C (better yields were observed with longer reaction times). Upon
completion, the reaction mixture was concentrated under reduced pressure and purified
by flash column chromatography (100 % hexanes) to afford the desired product 6 as a
yellow solid (500 mg, 57 %), Un-reacted 5 could be recovered by flushing the column
1
with 50 % dichloromethane/hexanes. H NMR (400 MHz, CDCl3) δ ppm 8.23 (s, 2H),
8.16 (s, 2H), 7.99 (d, J = 8.0 Hz, 2H), 7.82 (d, J = 8.0 Hz, 2H) 1.64 (s, 9H); 13C NMR
(100 MHz, CDCl3) δ ppm 149.0, 132.1, 130.3, 128.4, 126.4, 125.7, 122.6, 122.6, 122.1,
119.1, 35.0, 31.6; HRMS (ESI+) for C20H18Br [M + H]+ calculated: 337.0586 found:
337.0588.
7 Coventry, D. N.; Batsanov, A. S.; Goeta, A. E.; Howard, J. A. K.; Marder, T. B.; Perutz, R. N. Chem. Comm. 2005,
2172-2174.
8 Murphy, J. M.; Liao, X.; Hartwig, J. F. J. Am. Chem. Soc. 2007, 129, 15434-15435.
S4

Methyl 7-(tert-butyl)pyrene-2-carboxylate (S1): 2-bromo-7-(tert-butyl)pyrene (500
mg, 1.48 mmol, 1 equiv.) and triphenylphosphine (155 mg, 0.60 mmol, 0.4 equiv.) were
dissolved in anhydrous DMF (5 mL, 0.3 M) in a dry round bottom flask under N2.
Anhydrous methanol (2.4 mL, 59.2 mmol, 40 equiv.), Pd(OAc)2 (67 mg, 0.3 mmol, 0.2
equiv.) and anhydrous triethylamine (830 μl, 5.9 mmol, 4 equiv.) were then added to the
reaction mixture. Carbon monoxide was bubbled through the reaction via balloon for 30
minutes and the mixture was left to stir at room temperature for 5 h. Carbon monoxide
was again bubbled through the solution via balloon for 30 minutes and the reaction
o
mixture was warmed to 90 C for 16 h. Upon completion, the reaction was diluted with
ethyl acetate and water and the phases separated. The aqueous phase was extracted with
EtOAc (3X) and the combined organic extracts were washed with saturated CuSO4(aq)
and brine and dried over Na2SO4. Following filtration through a Fisherbrand P8-creped
coarse filter paper, the organic phase was concentrated under reduced pressure and
purified by flash column chromatography (100 % hexanes to 10 % ethyl acetate/hexanes)
1
to afford the desired product S1 as a yellow solid (188 mg, 40 %). H NMR (300 MHz,
CDCl3) δ ppm 8.82 (s, 2H), 8.25 (s, 2H), 8.12 (d, J = 8.0 Hz, 2H), 8.09 (d, J = 8.0 Hz,
2H), 4.08 (s, 3H), 1.59 (s, 9H); 13C NMR (75 MHz, CDCl3) δ ppm 168.0, 150.6, 131.8,
130.8, 128.5, 127.8, 127.0, 127.0, 125.7, 122.8, 122.7, 52.5, 35.5, 32.0; HRMS (ESI+)
for C22H21O2 [M + H]+ calculated: 317.1536 found: 317.1535.
(7-(tert-butyl)pyren-2-yl)methanol (7): Lithium aluminium hydride (250 mg, 6.6 mmol,
6 equiv.) was dissolved in anhydrous tetrahydrofuran (7.3 mL, 0.15 M) in a dry round
o
bottom flask under N2 and the reaction mixture was cooled to 0 C. Methyl 7-(tert-
butyl)pyrene-2-carboxylate S1 (350 mg, 1.1 mmol, 1 equiv.) was then added and the
o
reaction was left to stir at 0 C for 30 min and then allowed to warm up to room
temperature and stir for 1 h. Careful monitoring of the reduction by TLC is required to
prevent over-reduction. Upon complete consumption of the ester S1, the reaction was
o
cooled to 0 C and slowly quenched with 10 % NaOH and water. Ethyl Acetate and an
excess of Rochelle’s salt were then added and the mixture was left to stir overnight. The
reaction was diluted with ethyl acetate and the phases separated. The aqueous phase was
washed with ethyl acetate (3X) and the combined organic extracts were washed with
brine and dried over Na2SO4. Following filtration the organic phase was concentrated
under reduced pressure and purified by flash column chromatography (100 % hexanes to
30 % ethyl acetate/hexanes) to afford 7 as a white solid. (316 mg, 99 % yield). 1H NMR
(400 MHz, CDCl3) δ ppm 8.22 (s, 2H), 8.16 (s, 2H), 8.07 (d, J = 8.0 Hz, 2H), 8.04 (d, J =
8.0 Hz, 2H), 5.15 (d, J = 4 Hz, 2H), 1.59 (s, 9H); 13C NMR (100 MHz, CDCl3) δ ppm
S5

149.1, 138.1, 131.2, 130.9, 127.9, 127.1, 124.1, 123.2, 122.7, 122.4, 65.9, 35.2, 31.9;
HRMS (ESI+) for C21H21O [M + H]+ calculated: 289.1587 found: 289.1585.
7-(tert-Butyl)pyrene-2-carbaldehyde (S2): 7-(tert-butyl)pyren-2-yl)methanol (41 mg,
0.14 mmol, 1 equiv.) was dissolved in dichloromethane (7 mL, 0.02 M) in a round
bottom flask. Pyridinium chlorochromate (127 mg, 0.59 mmol, 4.2 equiv.) was added to
the solution and the reaction mixture was left to stir 2h at ambient temperature. The
reaction was diluted with diethyl ether and silica gel (~20 mg) was added. The mixture
was filtered through a thin pad of silica gel, washed with diethyl ether and the filtrate
concentrated under reduced pressure to afford the desired product S2 as a beige solid (40
mg, 99 %). 1H NMR (300 MHz, CDCl3) δ ppm 10.42 (s, 1H), 8.60 (s, 2H), 8.27 (s, 2H),
8.12 (s, 4H), 1.60 (s, 9H); 13C NMR (100 MHz, CDCl3) δ ppm 193.0, 150.8, 133.0, 131.7,
131.0, 128.8, 127.8, 127.6, 125.4, 123.0, 122.5, 35.4, 31.8; HRMS (ESI+) for C21H19O
[M + H]+ calculated: 287.1430 found: 287.1425.
2-(Bromomethyl)-7-(tert-butyl)pyrene (S3):9 Bromine (10 μL, 0.10 mmol, 1.30 equiv.)
was added to a suspension of triphenylphosphine (25.7 mg, 0.10 mmol, 1.30 equiv) and
imidazole (6.7 mg, 0.10 mmol, 1.30 equiv) in anhydrous dichloromethane (660 μL, 0.09
M) in a dry round bottom flask under N2 at 0 C. (7-(tert-butyl)pyren-2-yl)methanol
(0.0189g, 0.06 mmol, 1.00 equiv) was added slowly and the resulting mixture left to stir
for 18 h at room temperature. Once complete, the reaction was quenched with
NaHCO3(aq.), diluted with diethyl ether and the phases separated. The aqueous phase was
extracted with diethyl ether (3X) and the combined organic extracts were washed with
brine and dried with Na2SO4. Following filtration the organic phase was concentrated
under reduced pressure and purified by flash column chromatography (100 % hexanes to
1
5% diethyl ether/hexanes) to afford S3 as a beige solid. (16.7 mg, 73 %). H NMR (300
MHz, CDCl3)  ppm 8.23 (s, 2H), 8.15 (s, 2H), 8.08 (d, J = 9 Hz, 2H), 8.01 (d, J = 9 Hz,
9 Yang, C.-T.; Zhang, Z.-Q.; Liang, J.; Liu, J.-H.; Lu, X.-Y.; Chen, H.-H.; Liu, L. J. Am. Chem. Soc. 2012,
134, 11124-11127.
S6

2H), 4.94 (s, 2H), 1.59 (s, 9H); 13C NMR (75 MHz, CDCl3)  ppm 149.6, 135.0, 131.4,
131.2, 128.4, 127.1, 125.2, 124.5, 122.7, 35.4, 34.4, 32.1; HRMS (ESI+) for C21H20Br [M
+ H]+ calculated: 351.0743 found: 351.0726.
2-(tert-Butyl)-7-(2-(naphthalen-2-yl)vinyl)pyrene (9): To a solution of (naphthalene-2-
ylmethyl)triphenylphosphonium bromide (307 mg, 0.63 mmol, 1.1 equiv.) in anhydrous
tetrahydrofuran (3 mL, 0.2 M) freshly titrated n-BuLi (0.39 mL, 0.66 mmol, 1.15 equiv.)
was added dropwise under N2 at 0 oC,. The resulting yellow mixture was stirred for 1 h at
0 oC, then cooled to -78 oC and 7-(tert-butyl)pyrene-2-carbaldehyde (165 mg, 0.57 mmol,
1 equiv.) was added as a solution in tetrahydrofuran (4 mL, 0.14 M). The resulting red
mixture was warmed to room temperature and stirred for 18 h. Water was added to the
reaction mixture and the aqueous and organic phases were separated. The aqueous phase
was extracted with ethyl acetate (3x) and the combined organic layers were washed with
brine, dried over Na2SO4, filtered and concentrated. The crude mixture was purified by
flash column chromatography (100% hexanes) to afford the desired product 9 as a
mixture of cis- and trans isomers (1:3 ratio), as a yellow solid (219 mg, 94%). (spectral
data reported is for the isolated mixture of isomers): 1H NMR (300 MHz, CDCl3)  ppm
8.33 (s, 2H), 8.22 (s, 2H), 8.11 - 8.02 (m, 4H), 7.98 (s, 1H), 7.93 - 7.82 (m, 5H), 7.63 (d,
13
J = 2.1 Hz, 2H), 7.59 - 7.43 (m, 2H), 1.61 (s, 9H); C NMR (75 MHz, CDCl3)  ppm
149.1, 134.9, 134.6, 133.8, 133.1, 131.3 (2C), 130.9 (2C), 129.6, 129.5, 128.4, 128.1,
128.0 (2C), 127.7, 127.3 (2C), 126.8, 126.4 (2C), 125.9, 124.3, 123.6, 122.9 (2C), 122.4
(2C), 35.2, 31.9 (3C); HRMS (ESI) m/z C32H26Ag [M+Ag]+, calculated: 517.1080;
found: 517.1077.
t-Bu
t-Bu
Cu(MeCN)4BF4 (25 mol %)
Xantphos (25 mol%)
Neocuproine (25 mol%)
Propylene oxide (50 equiv.)
I2 (1 equiv.), THF (0.005 M)
120 h, visible light
23%
Pyrene/helicene hybrid (1): [Cu(MeCN)4]BF4 (6.7 mg, 0.02 mmol, 25 mol %) and
Xantphos (12.1 mg, 0.02 mmol, 25 mol %) were dissolved in anhydrous tetrahydrofuran
(4.2 mL, 5 mM) in a round bottom flask. The mixture was stirred for 1 h at room
temperature and neocuproine (4.4 mg, 0.02 mmol, 25 mol %) was added as a solution in
S7

tetrahydrofuran (5.3 mL, 4.0 mM) and the resulting yellow solution was stirred for 1 h. 2-
(tert-butyl)-7-(2-(naphthalen-2-yl)vinyl)pyrene 9 (35 mg, 0.09 mmol, 1 equiv.) was then
added followed by I2 (21.6 mg, 0.09 mmol, 1 equiv.), propylene oxide (0.30 mL, 4.3
mmol, 50 equiv.) and tetrahydrofuran (8 mL) to achieve a final concentration of 5mM.
The reaction was stirred in front of a compact fluorescent lamp (energy saving lightbulb
30W) for 120 h. The reaction was quenched with a saturated sodium thiosulfate solution
and diluted with ethyl acetate. The aqueous and organic phases were separated and the
aqueous layer was extracted with ethyl acetate (3X) and the combined organic extracts
were washed with brine, dried over Na2SO4, filtered and concentrated. The crude mixture
was purified by a flash column chromatography ((hexanes/toluene/dichloromethane,
98:1:1) to afford the desired product 1 as a pale yellow solid (8.6 mg, 23 %). 1H NMR
(400 MHz, CDCl3)  ppm 8.59 (s, 1H), 8.58 (d J = 8.4 Hz, 1H), 8.42 (d, J = 8.8 Hz,
1H), 8.23 (s, 2H), 8.16 (m, 2H), 8.10 - 7.91 (m, 6H), 7.57 (t, J = 7.4 Hz, 1H), 7.32 (t, J =
7.4 Hz, 1H), 1.63 (s, 9H); 13C NMR (75 MHz, CDCl3)  ppm 149.3, 132.5, 131.7, 131.5,
131.13, 131.05, 131.03, 130.0, 129.0, 129.1, 128.4, 128.2, 127.8, 127.6, 127.5, 126.9,
126.4, 126.2, 126.0, 125.2, 124.8, 124.0, 123.8, 123.6, 123.1, 122.8, 122.1, 35.2, 31.9
(3C); HRMS (ESI) m/z C32H24 [M]+, calculated: 408.1873; found: 408.1872.
Pyrene/helicene hybrid (1): [Cu(MeCN)4]BF4 (50 mg, 0.16 mmol, 25 mol %) and
Xantphos (93 mg, 0.16 mmol, 25 mol %) were dissolved in tetrahydrofuran (32 mL) in a
round bottom flask. The mixture was stirred for 1 h at room temperature, neocuproine (33
mg, 0.16 mmol, 25 mol %) was added as a solution in tetrahydrofuran (40 mL, 4 mM)
and the resulting yellow mixture was stirred for 1 h.10 2-(tert-butyl)-7-(2-(naphthalen-2-
yl)vinyl)pyrene 9 (264 mg, 0.64 mmol, 1 equiv.) was then added to the mixture as a
solution in tetrahydrofuran (60 mL, 0.01 M ), followed by I2 (162 mg, 0.64 mmol, 1
equiv.) and propylene oxide (2.2 mL, 32 mmol, 50 equiv.). The reaction mixture was
injected into the flow reactor for 18 h at a flow rate of 1 mL/min. The flow reaction was
conducted in a FlowSyn Multi-X reactor purchased from Uniqsis and equipped with a
modified HPLC pump. The reactor was connected to FEP tubing (fluorinated ethylene
polymer tubing purchased from IDEX Health & Science, #1673) of natural colour with
an outside diameter (OD) of 2 mm and inside diameter (ID) of 1 mm. 9 m of FEP tubing
was wrapped around four compact fluorescent lamps (30W energy saving light bulbs).
FEP tubing was chosen due to its high transmittance, high chemical resistance and
flexibility. Mild heating of the tubing during the reaction was observed. Following
10 For a procedure to form the discreet Cu catalyst see: Smith, C. S.; Branham, C. W.; Marquardt, B. J.;
Mann, K. R. J. Am. Chem. Soc. 2010, 132, 14079-14085.
S8

elution through the flow reactor, the reaction mixture was collected and quenched with a
saturated sodium thiosulfate solution. The aqueous and organic phases were separated,
the aqueous layer was extracted with ethyl acetate (3x) and the combined organic layers
were washed with brine, dried with Na2SO4, filtered and concentrated. The crude mixture
was purified by column chromatography (hexanes/toluene/dichloromethane, 98:1:1) to
afford the desired product 1 as a pale yellow solid (40 mg, 15 %).
2-(tert-Butyl)-7-(3,4,5-trimethoxystyryl)pyrene
(14):
2-(Bromomethyl)-7-(tert-
butyl)pyrene (66.8 mg, 0.19 mmol, 1.00 equiv.) was added to a suspension of
triphenylphosphine (51.4 mg, 0.20 mmol, 1.03 equiv) in hexanes (1.90 mL, 0.1 M) at
room temperature. The resulting mixture was heated to 60 C and left to stir for 48 h.
Once complete, the reaction was cooled to room temperature, filtered through a
Fisherbrand P8-creped coarse filter paper and the salt washed with a minimal amount of
diethyl ether to afford 8 as beige solid. (117 mg, 99 %). The phosphonium salt was
typically carried on the next step immediately. To a solution of 8 (0.381 g, 0.62 mmol,
1.13 equiv.) in anhydrous tetrahydrofuran (6.9 mL)was added dropwise was under N2 at
0oC, freshly titrated n-BuLi (1.67 M, 0.37 mL, 1.12 equiv.). The resulting yellow mixture
o
o
was stirred for 1 h at 0 C, then cooled to -78 C. 3,4,5-Trimethoxybenzaldehyde (0.108
g, 0.62 mmol, 1.12 equiv.) was then added and the resulting red solution was stirred for
18 h at room temperature. Water was added to the reaction mixture and the aqueous and
organic phases were separated. The aqueous phase was extracted with diethyl ether (3X)
and the combined organic layers were washed with brine, dried with Na2SO4, filtered and
concentrated. The crude mixture was purified by a flash column chromatography (20 %
diethyl ether/hexanes to 30% diethyl ether/hexanes) to afford the desired product 14 as a
4:3 ratio of cis- and trans isomers, as a yellow solid (106 mg, 38 % cis-14 and 84 mg, 30
% trans-14). (Z)-2-(tert-butyl)-7-(3,4,5-trimethoxystyryl)pyrene (cis-14): 1H NMR (300
MHz, CDCl3) δ ppm 8.20 (s, 2H), 8.12 (s, 2H), 8.02 (d, J = 9 Hz, 2H), 7.93 (d, J = 9 Hz,
2H), 6.99 (d, J = 12 Hz, 1H), 6.69 (d, J = 12 Hz, 1H), 6.59 (s, 2H), 3.85 (s, 3H), 3.48 (s,
6H), 1.59 (s, 9H); 13C NMR (75 MHz, CDCl3) δ ppm 153.04, 149.29, 137.56, 134.69,
132.53, 131.11, 130.99, 130.59, 130.32, 127.92, 127.25, 125.31, 123.87, 122.92, 122.45,
106.24, 61.05, 55.92, 35.38, 32.06; (E)-2-(tert-butyl)-7-(3,4,5-trimethoxystyryl)pyrene
(trans-14): 1H NMR (300 MHz, CDCl3) δ ppm 8.27 (s, 2H), 8.20 (s, 2H), 8.04 (s, 4H),
7.41 (d, J = 3 Hz, 2H), 6.87 (s, 2H), 3.98 (s, 6H), 3.91 (s, 3H), 1.59 (s, 9H). 13C NMR (75
MHz, CDCl3) δ ppm 153.6, 149.3, 138.2, 134.6, 133.4, 131.4, 131.1, 129.6, 128.9, 128.2,
127.4, 124.4, 123.0, 122.9, 122.6, 103.8, 61.2, 56.3, 35.4, 32.1; HRMS (ESI) m/z
C31H31NaO3 [M+Na]+ calculated: 473.2087; found 473.2087.
S9

Pyrene/helicene hybrid (2): [Cu(MeCN)4]BF4 (14.6 mg, 0.05 mmol, 25 mol %) and
Xantphos (26.8 mg, 0.05 mmol, 25 mol %) were dissolved in anhydrous tetrahydrofuran
(10 mL, 5 mM) in a round bottom flask. The mixture was stirred for 1 h at room
temperature and neocuproine (9.6 mg, 0.05 mmol, 25 mol %) was added as a solution in
tetrahydrofuran (2 mL, 0.025 M) and the resulting yellow solution was stirred for 1 h. 2-
(tert-Butyl)-7-(3,4,5-trimethoxystyryl)pyrene 14 (83.5 mg, 0.19 mmol, 1 equiv.) was then
added to the mixture as a solution in tetrahydrofuran (25 mL, 8 mM), followed by I2
(46.9 mg, 0.19 mmol, 1 equiv.) and propylene oxide (0.65 mL, 9.27 mmol, 50 equiv.).
The reaction was stirred in front of a compact fluorescent lamp (energy saving lightbulb
30W) for 120 h. The reaction was diluted with diethyl ether and quenched with a
saturated sodium thiosulfate solution. The aqueous and organic phases were separated
and the aqueous layer was extracted with diethyl ether (3X) and the combined organic
extracts were washed with brine, dried over Na2SO4, filtered and concentrated. The crude
mixture was purified by a flash column chromatography (hexanes/toluene/diethyl ether,
70:20:10) to afford the desired product 2 as a pale yellow solid (9.7 mg, 12%). 1H NMR
(700 MHz, CDCl3) δ ppm 8.60 (d, J = 9.1 Hz, 1 H) , 8.49 (s, 1 H), 8.28 (d, J = 1.4 Hz, 1
H), 8.22 (d, J = 2.1 Hz, 1 H), 8.15 (d, J = 9.1 Hz, 1 H), 8.12(d, J = 8.4 Hz, 1 H), 8.05 (d,
J = 9.1 Hz, 1 H), 7.96 (d, J = 8.4 Hz, 1 H), 7.79 (d, J = 8.4 Hz, 1 H), 7.27 (s, 1 H), 4.19
(s, 3 H), 4.12 (s, 3 H), 2.99 (s, 3 H), 1.62 (s, 6 H), 1.55(d, J = 0.1 Hz, 3 H). 13C NMR
(176 MHz, CDCl3) δ ppm 152.80, 151.73, 149.17, 142.28, 131.49, 131.04, 130.85,
129.88, 129.72, 129.69, 128.12, 127.51, 127.06, 126.61, 124.72, 123.93, 123.53, 123.00,
122.70, 122.37, 122.05, 117.87, 104.51, 62.05, 60.33, 56.29, 35.39, 32.10.HRMS (ESI)
m/z calculated for C31H29O3 [M+H]+, 449.2105; found 449.2111.
Pyrene/helicene hybrid (2): [Cu(MeCN)4]BF4 (19 mg, 0.06 mmol, 25 mol %) and
Xantphos (35 mg, 0.06 mmol, 25 mol %) were dissolved in tetrahydrofuran (13 mL) in a
round bottom flask. The mixture was stirred for 1 h at room temperature, neocuproine
(12.5 mg, 0.06 mmol, 25 mol %) was added as a solution in tetrahydrofuran (25 mL) and
S10

the resulting yellow mixture was stirred for
1
h. 2-(tert-Butyl)-7-(3,4,5-
trimethoxystyryl)pyrene 14 (109 mg, 0.24 mmol, 1 equiv.) was then added to the mixture,
followed by I2 (61 mg, 0.24 mmol, 1 equiv.) and propylene oxide (0.84 mL, 12 mmol, 50
equiv.). The reaction mixture was injected into the flow reactor for 18 h at a flow rate of
1 mL/min. The flow reaction was conducted in a VapourTech R4 reactor and a R2+
pumping module. The reactor was connected to FEP tubing (fluorinated ethylene polymer
tubing purchased from IDEX Health & Science, #1673) of natural colour with an outside
diameter (OD) of 2 mm and inside diameter (ID) of 1 mm. 9 m of FEP tubing was
wrapped around 3 compact fluorescent lamps (30W energy saving light bulbs). FEP
tubing was chosen due to its high transmittance, high chemical resistance and flexibility.
Mild heating of the tubing during the reaction was observed. Following elution through
the flow reactor, the reaction mixture was collected and quenched with a saturated
sodium thiosulfate solution. The aqueous and organic phases were separated, the aqueous
layer was extracted with ethyl acetate (3x) and the combined organic layers were washed
with brine, dried with Na2SO4, filtered and concentrated. The crude mixture was purified
by column chromatography (hexanes/toluene/diethyl ether, 70:20:10) to afford the
desired product 2 as a pale yellow solid (45 mg, 41 %).
2,7-Di-(tert-butyl)-4-bromopyrene
(17):
(2,7-di-(tert-butyl)pyren-4-yl)-4,4,5,5-
tetramethyl-1,3,2-dioxaborolane 16 (2.5 g, 5.72 mmol, 1 equiv.) and dry methanol (180
o
mL) were added to a dry round bottom flask. The reaction mixture was heated to 80 C
and then CuBr2 (3.8 g, 17.2 mmol, 3 equiv.) was added. The reaction was left to stir for
o
72 h at 80 C. Upon completion, the reaction mixture was concentrated under reduced
pressure and purified by a short column chromatography (100 % hexanes) to afford the
desired product 17 as a yellow solid (2.25 g, 99 %). The spectroscopic data are in
agreement with those previously reported.11
2,7-Di-(tert-butyl)-4-(carboxymethyl)pyrene (S4): 2,7-Di-(tert-butyl)-4-bromopyrene
(400 mg, 1.0 mmol, 1 equiv.) and triphenylphosphine (122 mg, 0.47 mmol, 0.47 equiv.)
11 Yamato, T. ; Miyazama, A. ; Tashiro, M. J. Org. Chem. 1992, 57, 266-270.
S11

were dissolved in anhydrous DMF (4 mL) in a dry round bottom flask under N2.
Anydrous methanol (2.4 mL, 47.9 mmol, 48 equiv.), Pd(OAc)2 (53.3 mg, 0.23 mmol,
0.23 equiv.) and anhydrous triethylamine (670 μl, 4.8 mmol, 4.8 equiv.) were then added
to the reaction mixture. Carbon monoxide was bubbled through the reaction via balloon
for 30 minutes and the mixture was left to stir at room temperature for 5 h. Carbon
monoxide was again bubbled through the solution via balloon for 30 minutes and the
o
reaction mixture was warmed to 80 C for 10 h. Upon completion, the reaction was
diluted with ethyl acetate and water and the phases separated. The aqueous phase was
extracted with EtOAc (3X) and the combined organic extracts were washed with
saturated CuSO4(aq) and brine and dried over Na2SO4. Following filtration through a
Fisherbrand P8-creped coarse filter paper, the organic phase was concentrated under
reduced pressure and purified by flash column chromatography (100 % hexanes to 10 %
ethyl acetate/hexanes) to afford the desired product S4 as a pale yellow solid (350 mg, 97
%). 1H NMR (300 MHz, CDCl3) δ ppm 9.41 (d, J = 1.8 Hz, 1 H), 8.88 (s, 1 H), 8.29 (s, 2
H), 8.25 (d, J = 1.8 Hz, 1 H), 8.04 (m, 2 H), 4.13 (m, 3 H), 1.62 (s, 9 H), 1.59 (s, 9 H);
13C NMR (75 MHz, CDCl3) δ ppm 168.3, 149.3, 149.0, 133.8, 130.8, 130.7, 128.9, 128.2,
127.8, 126.7, 126.2, 124.4, 124.0, 123.8, 123.4, 122.7, 121.5, 52.2, 35.5, 35.2, 32.0, 31.9;
HRMS (ESI+) for C26H28O2 [M + H]+ calculated: 372.2162 found: 372.2162.
(2,7-Di-tert-butylpyren-5-yl)methanol (18): To a solution of 2,7-di-(tert-butyl)-4-
(carboxymethyl)pyrene (100 mg, 0.27 mmol, 1 equiv.) in THF (3 mL) at 0 oC was added
lithium aluminium hydride (41 mg, 1.1 mmol, 4 equiv.). The reaction was left to stir at 0
oC for 30 min and then allowed to warm up to room temperature and stir for 1 h. Careful
monitoring of the reduction by TLC is required to prevent over-reduction. Upon complete
o
consumption of the ester S4, the reaction was cooled to 0 C and slowly quenched with
10 % NaOH and water. Ethyl Acetate and an excess of Rochelle’s salt were then added
and the mixture was left to stir 3h. The reaction was diluted with ethyl acetate and the
phases separated. The aqueous phase was washed with ethyl acetate (3X) and the
combined organic extracts were washed with brine and dried over Na2SO4. Following
filtration the organic phase was concentrated under reduced pressure and purified by flash
column chromatography (30 % ethyl acetate/hexanes) to afford 18 as a pale yellow solid.
(93 mg, 99 % yield). The spectroscopic data are in agreement with those previously
reported.12
12 Yamato, T. ; Miyazama, A. ; Tashiro, M. J. Chem. Res. 2008, 8, 457-460.
S12

2,7-Di-tert-butylpyrene-4-carbaldehyde (S5): (2,7-Di-tert-butylpyren-5-yl)methanol
(40 mg, 0.12 mmol, 1 equiv.) was dissolved in dichloromethane (2 mL) in a round
bottom flask. Pyridinium chlorochromate (100 mg, 0.46 mmol, 4 equiv.) was added to the
solution and the reaction mixture was left to stir 1h at ambient temperature. The reaction
was diluted with diethyl ether and silica gel (~20 mg) was added. The mixture was
filtered through a thin pad of silica gel, washed with diethyl ether and the filtrate
concentrated under reduced pressure to afford the desired product S5 as a pale yellow
solid (39 mg, 99 %). The spectroscopic data are in agreement with those previously
reported.12
2,7-Di-tert-butyl-4-(2-(naphthalen-3-yl)vinyl)pyrene (19): To a solution of 10 (189.5
mg, 0.39 mmol, 1.1 equiv.) in anhydrous tetrahydrofuran (2 mL) was added dropwise
under N2 at 0oC, freshly titrated n-BuLi (1.15 M, 0.35 mL, 1.15 equiv.). The resulting
yellow mixture was stirred for 1 h at 0 oC, then cooled to -78 oC. 2,7-Di-tert-butylpyrene-
4-carbaldehyde (121 mg, 0.35 mmol, 1.0 equiv.) was then added and the resulting red
solution was stirred for 18 h at room temperature. Water was added to the reaction
mixture and the aqueous and organic phases were separated. The aqueous phase was
extracted with diethyl ether (3X) and the combined organic layers were washed with
brine, dried with Na2SO4, filtered and concentrated. The crude mixture was purified by a
flash column chromatography (20 % diethyl ether/hexanes to 30% diethyl ether/hexanes)
to afford the desired product 19 as a mixture of cis- and trans isomers, as a pale yellow
1
solid (115 mg, 71 %). H NMR (data reported for the major isomer only, 400 MHz,
CDCl3) δ ppm 8.57 (d, J = 1.6 Hz, 1 H), 8.37 (s, 1 H), 8.27 (dd, J = 6.4, 1.6 Hz, 2 H),
8.24 - 8.16 (m, 2 H), 8.06 (d, J = 1.6 Hz, 2 H), 8.03 (s, 1 H), 7.98 - 7.88 (m, 4 H), 7.58 (d,
13
J = 16.1 Hz, 1 H), 7.53 (dt, J = 7.1, 1.4 Hz, 2 H), 1.64 (s, 9 H), 1.62 (s, 9H); C NMR
(100 MHz, CDCl3) δ ppm 148.8, 148.4, 135.3, 134.6, 133.8, 133.2, 132.0, 131.2, 130.7,
130.6, 129.7, 128.5, 128.1, 127.8, 127.7, 127.3, 126.92, 126.88, 126.4, 126.0, 125.0,
123.8, 123.1, 122.6, 122.4, 122.3, 122.1, 118.5, 35.4, 35.2, 32.1, 31.9; HRMS (ESI) m/z
C36H35 [M+H]+, calculated: 467.2733; found 467.2728.
S13

Pyrene/helicene hybrid (3): [Cu(MeCN)4]BF4 (7.9 mg, 0.025 mmol, 25 mol %) and
Xantphos (14.5 mg, 0.025 mmol, 25 mol %) were dissolved in anhydrous tetrahydrofuran
(15 mL) in a round bottom flask. The mixture was stirred for 1 h at room temperature and
neocuproine (5.2 mg, 0.025 mmol, 25 mol %) was added as a solution in tetrahydrofuran
(5 mL) and the resulting yellow solution was stirred for 1 h. 2,7-Di-tert-butyl-4-(2-
(naphthalen-3-yl)vinyl)pyrene 19 (48 mg, 0.10 mmol, 1 equiv.) was then added to the
mixture as a solution in tetrahydrofuran (10 mL), followed by I2 (25.4 mg, 0.10 mmol, 1
equiv.) and propylene oxide (0.35 mL, 5.0 mmol, 50 equiv.). The reaction was stirred in
front of a compact fluorescent lamp (energy saving lightbulb 30W) for 120 h. The
reaction was diluted with diethyl ether and quenched with a saturated sodium thiosulfate
solution. The aqueous and organic phases were separated and the aqueous layer was
extracted with diethyl ether (3X) and the combined organic extracts were washed with
brine, dried over Na2SO4, filtered and concentrated. The crude mixture was purified by a
flash column chromatography (toluene/pentane, 5:95) to afford the desired product 3 as a
yellow solid (12 mg, 27%). 1H NMR (400 MHz, CDCl3) δ ppm 8.95 (s, 1 H), 8.85 (d, J =
8.4 Hz, 1 H), 8.79 (s, 1 H), 8.37 (d, J = 8.4 Hz, 1 H), 8.25 (d, J = 1.7 Hz, 1 H), 8.11 (d, J
= 1.8 Hz, 1 H), 8.06 (s, 2 H), 8.03 (s, 1 H), 7.99 - 7.91 (m, 4 H), 7.48 (t, J = 7.4 Hz, 1 H),
7.22 - 7.13 (m, 1 H), 1.82 - 1.64 (m, 9 H), 1.29 (s, 9 H); 13C NMR (100 MHz, CDCl3) δ
ppm 148.8, 146.8, 132.8, 132.5, 131.3, 131.1, 130.7, 129.7, 128.8, 128.7, 128.1, 127.9,
127.8, 127.6, 127.50, 127.47, 127.0, 126.1, 126.0, 125.3, 124.4, 122.7, 122.6, 122.4,
122.3, 122.0, 118.2, 35.5, 35.0, 32.0, 31.5; HRMS (ESI) m/z C36H34 [M+H]+ calculated:
465.2577; found 465.2580.
Pyrene/helicene hybrid (3): [Cu(MeCN)4]BF4 (7.9 mg, 0.025 mmol, 25 mol %) and
Xantphos (14.5 mg, 0.025 mmol, 25 mol %) were dissolved in anhydrous tetrahydrofuran
(15 mL) in a round bottom flask. The mixture was stirred for 1 h at room temperature and
neocuproine (5.2 mg, 0.025 mmol, 25 mol %) was added as a solution in tetrahydrofuran
(5 mL) and the resulting yellow solution was stirred for 1 h. 2,7-Di-tert-butyl-4-(2-
(naphthalen-3-yl)vinyl)pyrene 19 (48 mg, 0.10 mmol, 1 equiv.) was then added to the
S14

mixture as a solution in tetrahydrofuran (10 mL), followed by I2 (25.4 mg, 0.10 mmol, 1
equiv.) and propylene oxide (0.35 mL, 5.0 mmol, 50 equiv.). The reaction mixture was
injected into the flow reactor for 18 h at a flow rate of 1 mL/min. The flow reaction was
conducted in a VapourTech R4 reactor and a R2+ pumping module. The reactor was
connected to FEP tubing (fluorinated ethylene polymer tubing purchased from IDEX
Health & Science, #1673) of natural colour with an outside diameter (OD) of 2 mm and
inside diameter (ID) of 1 mm. FEP tubing was chosen due to its high transmittance, high
chemical resistance and flexibility. Mild heating of the tubing during the reaction was
observed. Following elution through the flow reactor, the reaction mixture was collected
and quenched with a saturated sodium thiosulfate solution. The aqueous and organic
phases were separated, the aqueous layer was extracted with ethyl acetate (3x) and the
combined organic layers were washed with brine, dried with Na2SO4, filtered and
concentrated. The crude mixture was purified by a flash column chromatography
(toluene/pentane, 5:95) to afford the desired product 3 as a yellow solid (22 mg, 46%).
S15

UV VIS
The absorbance was recorded on a Cary100 using a 1 cm trajectory and a blank cell
(DCM) for each sample.
[5]helicene (2.1 mg) was dissolved in 1.5 mL of DCM to make a stock solution (5.03x10-
3M) and was then diluted to achieve an appropriate concentration for measurement
(1.52x10-4M).
Pyrene/helicene hybrid 1 (2.2 mg) was dissolved in 0.5 mL of DCM to make a stock
solution (1.08x10-2M) and was then diluted to achieve an appropriate concentration for
measurement (8.90x10-5M).
Pyrene/helicene hybrid 2 (2.0 mg) was dissolved in 1.0 mL of DCM to make a stock
solution (4.46x10-3M) and was then diluted to achieve an appropriate concentration for
measurement (1.84x10-4M).
Pyrene/helicene hybrid 3 (12.9 mg) was dissolved in 10.0 mL of DCM to make a stock
solution (2.76x10-3M) and was then diluted to achieve an appropriate concentration for
measurement (8.46x10-5M).
S16

FLUORESCENCE
The measurements were recorded using a PTI fluorometer at 2 nm / 0.2 s. (band widths
for the excitation and emission monochromator were 0.4 nm and 1 nm, respectively). The
sampling cell was kept at 20 °C. The same solutions were used from the absorbance
measurement; [5]helicene (1.52x10-4M); Pyrene/helicene hybrid 1 (8.90x10-5M);
Pyrene/helicene hybrid 2; (1.84x10-4M); Pyrene/helicene hybrid 3; (8.46x10-5M).
S17

HOMO/LUMO REPRESENTATIONS
Figure S1 – a) Optimized geometries of compounds 1a to 3 and b) corresponding HOMO (left)
and LUMO (right) calculated by using the B3LYP/6-31G(d,p) method with IEFPCM of
dichloromethane.
1a
a)
b)
HYBRID 1
a)
b)
S18

HYBRID 2
a)
b)
HYBRID 3
a)
b)
S19

SPECTRAL DATA
S20

S21

13
3
C NMR (75 MHz, CDC)l
O
O
B
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
f1 (ppm)
S22

S23

S24

S25

1H NMR (400 MHz,
CDC3l)
O
H
12.0 11.5 11.0 10.5 10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
f1 (ppm)
S26

13
3
C NMR (75 MHz, CDC)l
Br
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
f1 (ppm)
S27

S28

1
3
H NMR (300 MHz, CDC)l
O
O
O
7.1 7.0 6.9 6.8 6.7 6.6 6.5
f1 (ppm)
8.2
8.1
f1 (ppm)
8.0
7.9
12.0 11.5 11.0 10.5 10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
f1 (ppm)
13
3
C NMR (75 MHz, CDC)l
O
O
O
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
f1 (ppm)
S29