Probing Diels-Alder reactivity on a model CNT sidewall

Article abstract of DOI:10.1016/j.tet.2016.03.077

We have synthesized a cycloparaphenylene containing a perylene motif that is a model for a carbon nanotube sidewall. The reactivity of the sidewall model towards a Diels-Alder reaction using a masked acetylene was examined and similar reactivity was observed between the macrocyclic and planar substrate. This study suggests that a Diels-Alder reaction is a viable method for carbon nanotube growth using an appropriate template.

Full text of DOI:10.1016/j.tet.2016.03.077

Accepted Manuscript
Probing Diels-Alder Reactivity on a Model CNT Sidewall
Evan P. Jackson, Thomas J. Sisto, Evan R. Darzi, Ramesh Jasti
PII:
S0040-4020(16)30207-1
10.1016/j.tet.2016.03.077
TET 27617
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 1 January 2016
Revised Date: 14 March 2016
Accepted Date: 22 March 2016
Please cite this article as: Jackson EP, Sisto TJ, Darzi ER, Jasti R, Probing Diels-Alder Reactivity on a
Model CNT Sidewall, Tetrahedron (2016), doi: 10.1016/j.tet.2016.03.077.
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Probing Diels-Alder Reactivity on a Model
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Evan P. Jackson, Thomas J. Sisto, Ramesh Jasti*
Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States

1
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Tetrahedron
journal homepage: www.elsevier.com
Probing Diels-Alder Reactivity on a Model CNT Sidewall
Evan P. Jackson, Thomas J. Sisto, Evan R. Darzi, Ramesh Jasti*
a
Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403, United States
rjasti@uoregon.edu
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
We have synthesized a cycloparaphenylene containing a perylene motif that is a model for a
carbon nanotube sidewall. The reactivity of the sidewall model towards a Diels-Alder reaction
using a masked acetylene was examined and similar reactivity was observed between the
macrocyclic and planar substrate. This study suggests that a Diels-Alder reaction is a viable
method for carbon nanotube growth using an appropriate template.
Available online
2
009 Elsevier Ltd. All rights reserved.
Keywords:
Diels-Alder
Perylene
Cycloparaphenylenes
Polycyclic aromatic hydrocarbon
Carbon Nanotubes
1
. Introduction
creating a new bay region with each cycloaddition.
In principle, a small hydrocarbon template should provide the
necessary architecture for dictating the diameter and chirality for
growing a CNT using a cycloaddition reaction. The simplest
Carbon nanotubes (CNTs) have unique optoelectronic
properties that are highly dependent on the chiral index (i.e.
1
structure and diameter) of the CNT. Although promising as a
new material, current CNT synthesis is hampered by a lack of
structural control. Currently no scalable method exists to produce
2
homogenous CNTs with a predefined chiral index. A promising
approach towards overcoming this challenge is to utilize a
template for growing CNTs that would predefine the chirality
3
and diameter of the resultant nanotube. One proposed strategy to
grow CNTs from a template is to utilize a Diels-Alder
cycloaddition with acetylene or an acetylene equivalent as a
carbon feedstock on an extended cycloparaphenylene template.
This is an attractive method since no new nanotubes are created
under Diels-Alder conditions and CNTs can only be elongated
from existing templates with predefined diameter and chirality. In
the reaction, an acetylene dieneophile would undergo [4+2]
cycloaddition with the diene bay region of the template to form a
new 6-membered ring, followed by rapid extrusion of H to
2
4
regain aromaticity. (Figure 1) Continuing this process on an
adjacent bay region would subsequently form another new bay
region and this process can continue indefinitely, sequentially
Figure 2: a: Early work from Clar b: Scott’s system using
nitroethylene c. Diels-Alder on perylene in a macrocyclic
system
Figure 1: A proposed method for growing CNTs using a
Diels-Alder reaction

2
Tetrahedron
ACCEPTED MANUSCRIPT
1
13
through H and C NMR spectroscopy as well as mass
spectrometry.
Scheme 1: Synthesis of a model CNT sidewall (5)
model for this system would be biphenyl which upon
cycloaddition and rearomatization would yield phenanthrene.
Unfortunately, no known Diels-Alder reaction exists on biphenyl
likely due to the high loss of aromatic stabilization energy that
accompanies cycloaddition. Although biphenyl is unreactive
4
under Diels-Alder conditions, previous work from Scott and
5
Clar showed that cycloaddition and rearomatization was indeed
possible on larger polycyclic aromatic hydrocarbon (PAH)
systems. The Diels-Alder reaction on a bay region of a PAH was
5
first shown on perylene by Clar using maleic anhydride and
4
chloranil as an oxidant (Figure 2a). More recently Scott has
4c
shown that a variety of dieneophiles, including nitroethylene
undergo cycloaddition with perylene and subsequent loss of
HONO and H re-aromatizes the ring forming benzannulated
2
perylene (Figure 2b). While extensive work has been conducted
with flat perylene or bisanthese derivatives to study the reactivity
in the bay 4b,6region for cycloaddition, no work has
experimentally
examined a7 [4+2] cycloaddition in a
macrocyclic cycloparaphenylene system that would serve a
model for nanotube growth. Herein, we report our efforts at
synthesizing cyclo(3,9)-perylenehepta(paraphenylene) (5) a CPP
containing a perylene fragment embedded in the macrocycle, as
well as the viability of this model to undergo a Diels-Alder
reaction with nitroethylene for benzannulation.
2
. Results and discussion
To experimentally investigate a Diels-Alder reaction on a
model CNT sidewall we envisioned synthesizing
a
cycloparaphenylene (CPP) macrocycle containing a perylene
subunit. The synthetic strategy utilized methodology similar to
our previous syntheses of CPPs with cyclohexadiene units acting
Figure 3: UV-Vis and fluorescence of perylene CPP and flat
perylene in methylene chloride
8
as masked benzene rings. To incorporate perylene into a CPP we
Notably the UV-Vis spectrum of 5 compared to flat perylene
6) shows significantly red shifted absorbance. The λmax value for
envisioned a synthetic plan outlined in Scheme 1 where
functionalized perylene is incorporated in a late stage Suzuki-
Miyaura macrocyclization reaction. Dibromide 3 can be accessed
from precursor 1 through double lithiation and nucleophilic
addition to ketone 2. Functionalized perylene was synthesized
(
the most intense absorption of 5 is 313 nm with an absorption
4
-1
-1
coefficient of 4.05 x 10
M
cm . Unlike many CPPs, the
11
HOMO-LUMO transition is not symmetry forbidden and we
4
-1
-1
observe an absorbance at 518 nm (ε = 1.23 x 10 M cm ) which
was corroborated with time-dependent DFT (TD-DFT)
calculations. We also observe a red shifted fluorescence for 8
compared to flat perylene. The unique photophysical behavior of
through bromination of perylene to afford a mixture of 3,10 and
9
3
,9 dibromoperylene
and we found that repeated
recrystallization in 5/3 aniline/toluene afforded enriched 3,9-
dibromoperylene in a ratio of 16:1. Subsequent Miyaura
borylation of 3,9-dibromoperylene afforded the desired bis-
boronate coupling partner and the structure was unambiguously
confirmed by X-ray crystallographic analysis as the substituted
5
5
warrants further investigation (Figure 3). The quantum yield for
was 0.21 which is significantly lower than previously reported
12
value of 0.94 for flat perylene , however, is comparable to
similarly sized [8]CPP (0.10) and [9]CPP (0.38).
13
We also
3
,9-perylene. Suzuki-Miyaura cross coupling using Buchwald’s
observed much greater solubility of 5 in common organic
solvents compared to 6.
second generation SPhos precatalyst between 3 and the
bis(boronate) afforded macrocycle 4 in moderate yield with
partial silyl deprotection observed. Next, TBAF deprotection of
the remaining silyl ethers and subsequent aromatization using
With our desired target molecule in hand, we next examined
the Diels-Alder reactivity of the system. Diethyl
acetylenedicarboxylate was initially employed as a dienophile
using similar conditions to what Scott had previously reported.
Although we found the diester to be reactive, the benzannulated
10
SnCl /HCl afforded 5 cyclo(3,9)-perylenehepta(paraphenylene),
2
4
d
a fragment of a (10,8) CNT. The structure of 5 was confirmed

3
ACCEPTED MA
a
N
ma
U
sk
S
ed
C
a
R
ce
I
tylene equivalent and is a reactive dieneophile for
P
T
cycloaddition on the bay region of perylene incorporated into a
macrocyclic structure. These results show that perylene
incorporated into a macrocycle displays similar reactivity to the
flat substrate (at least for this macrocyclic ring size) suggesting
that Diels-Alder cycloaddition is a viable strategy for nanotube
growth when using an appropriate template.
4
. Experimental
Unless otherwise noted all reactions were conducted in flame-
dried or oven dried (120 °C) glassware with magnetic stirring
under an atmosphere of dry nitrogen. All reagents were used as
1
13
received. H and C NMR spectra were obtained on a Varian
INOVA-500, Bruker Avance III-HD 500, or Bruker Avance II-
1
HD 600 spectrometer. Chemical shifts of H NMR spectra were
recorded in parts per million (ppm) on the δ scale from an
internal standard of residual chloroform (7.24 ppm). Chemical
13
shifts of C NMR spectra were recorded in ppm from the central
Scheme 2: Diels-Alder on perylene (6) and cyclo(3,9)-
perylenehepta(paraphenylene) (8)
peak of CDCl (77.0 ppm) on the δ scale. Absorbance spectra
3
were obtained using dichloromethane as the solvent in a 1 cm
quartz cuvette on an Agilent Cary 60 UV-Vis spectrophotometer.
Emission spectra were collected using dichloromethane as the
solvent in a 1 cm quartz cuvette using a Horiba Jobin Yvon
FluoroMax-4 spectrophotometer. THF, toluene and DMF were
dried by filtration through alumina according to the methods
described by Grubbs. 1,2-Dichlorobenzene (Aldrich anhydrous)
was used as received. Silica gel column chromatography was
conducted with Zeochem Zeoprep 60 Eco 40-63 µm silica gel.
Thin layer chromatography (TLC) was performed using Sorbent
Technologies Silica Gel XHT TLC plates. Developed plates were
visualized using UV light at wavelengths of 254 and 365 nm.
product rapidly decomposed on silica gel proving difficult to
isolate and characterize. Additionally, we examined in situ
4c
generated nitroethylene and found it also appeared to undergo
cycloaddition and rearomatization with (Scheme 2).
Unfortunately, all efforts to separate the benzannulated product
8) from the starting material were unsuccessful; however,
5
15
(
1
examination of the H NMR spectrum strongly suggests
successful product formation based the appearance of multiple
downfield shifted peaks which would be expected in that region
from desymmetrization of the molecule (Figure 4). This trend is
also observed when comparing perylene to benzo[ghi]perylene.
Additionally, the MALDI-TOF spectrum shows a peak at 807
+
consistent with a [M+H] ion expected for 8. Based on our
2
4
, 4'-bromo-1-((triethylsilyl)oxy)-[1,1'-biphenyl]-4(1H)-one:
'-bromo-1-hydroxy-[1,1'-biphenyl]-4(1H)-one (6.00 g, 22.6
identification of 8, we can conclude the ratio of 8 to 5 is 1.2:1 in
the isolated mixture, similar to what is observed when flat
perylene is reacted under analogous conditions (Scheme 2).
Although we were unsuccessful at isolating the benzannulated
product, this study demonstrates that a Diels-Alder reaction is
feasible on a curved aromatic system and it shows similar
reactivity to when a planar substrate is employed.
mmol, 1 equiv) was combined with imidazole (3.07 g, 45.1
mmol, 2 equiv) in a 250 mL flask and dissolved in 112 mL DMF
at room temperature. Et SiCl (5.2 g, 34.5 mmol, 1.5 equiv) was
3
added dropwise to the solution. Following addition of Et SiCl,
3
the flask was immersed in an oil bath and heated to 40 °C and
stirred overnight. The reaction was allowed to cool to rt then
quenched with saturated aqueous NaHCO and extracted with
3
EtOAc. The aqueous phase was extracted 3x with EtOAc then the
organic layer was washed with aqueous NaHCO , twice with
3
H O, brine, and dried with Na SO . Solvent was removed in
2
2
4
vacuo and the crude residue was purified via flash
chromatography on silica gel (10% EtOAc/hexanes) to afford a
1
faint yellow oil (8.00 g, 92%). H NMR (500 MHz, CDCl ) δ
3
7
1
0
1
.45 (d, J = 8.6 Hz, 2H), 7.29 (d, J = 8.6 Hz, 2H), 6.76 (d, J =
0.0 Hz, 2H), 6.20 (d, J = 10.0 Hz, 2H), 0.95 (t, J = 7.9 Hz, 9H),
13
.63 (q, J = 7.9 Hz, 6H). C NMR (151 MHz, CDCl ) δ 185.6,
3
51.5, 139.1, 131.8, 127.2, 126.7, 122.1, 72.8, 6.9, 6.2. HRMS
(
3
CI+) (m/z): calculated for C H SiO Br 378.0651 found
78.0653. IR (film, cm ):2953, 2874, 1670, 1628, 1484.
18
23
2
-
1
10
3
, the corresponding dibromide (5.00 g, 7.68 mmol, 1 equiv)
was dissolved in 200 mL THF and cooled to -78 °C over 1 hour.
After cooling, nBuLi (2.5 M in hexanes, 15.2 mmol, 2 equiv) was
added to the solution over 1 min and allowed to stir for 2 min
after which ketone 2 (5.77g, 15.2 mmol, 2 equiv) was quickly
injected. The reaction was stirred at -78 °C for 1 hour then
1
Figure 4: H NMR of 5 and mixture of 8 and 5
quenched with 10 mL H O and allowed to warm to rt. The
reaction was diluted with EtOAc and the organic phase was
2
3
. Summary and conclusions
washed with H O, brine, and then dried with Na SO . Solvent
In conclusion, we have synthesized a CPP incorporating a
perylene moiety to investigate the reactivity of a Diels-Alder
reaction as a viable means for CNT growth. Nitroethylene acts as
2
2
4
was removed in vacuo and the crude reaction mixture was
purified via flash chromatography (5% EtOAc/hexanes)
affording the major diastereomer as a white solid (4.81 g, 50%).

41
Tetrahedron
H NMR (600 MHz, CDCl ) δ 7.38 (d, J = 8.6 Hz, 4H), 7.34 (s,
flash chromatography (35% CH Cl /pentane) affording a mixture
3
ACCEPTED MANUSCRIPT
2 2
8
5
0
7
1
7
H), 7.23 – 7.19 (m, 4H), 6.01 (d, J = 10.0 Hz, 4H), 5.97 (s, 4H),
.91 (d, J = 10.0 Hz, 4H), 2.04 (s, 2H), 0.97 (t, J = 7.9 Hz, 18H),
.91 (t, J = 7.9 Hz, 18H), 0.67 (q, J = 7.9 Hz, 12H), 0.59 (q, J =
.9 Hz, 12H). C NMR (151 MHz, CDCl ) δ 145.7, 144.8,
43.0, 132.7, 131.5, 131.2, 130.1, 127.4, 126.1, 125.4, 121.1,
of 8 and 10 with a combined mass of 5.0 mg (ratio 8:5, 1.2:1)
1
Characteristic peaks of 8 H NMR (500 MHz, CDCl3) δ 8.79 (d,
J = 7.8 Hz, 1H), 8.64 (d, J = 8.4 Hz, 1H), 8.61 (d, J = 7.9 Hz,
1H), 8.52 (d, J = 8.9 Hz, 1H), 8.19 (d, J = 8.3 Hz, 1H), 8.16
13
3
+
(
d, J = 8.4 Hz, 1H), 7.85 (s, 1H). MALDI-TOF (m/z) [M+H]
1.3, 71.2, 69.1, 7.1, 7.0, 6.5, 6.4. MADLI-TOF (m/z) [M]+
calculated for C H 807.3; found 807.1.
64
39
-
calculated for C H Br O Si 1248.4 found 1248.1, IR (film, cm
66
90
2
6
4
1
): 3373, 2951, 2874, 1675, 1483
7
, Benzo[ghi]perylene, perylene (25 mg, 0.099 mmol, 1 equiv)
and phthalic anhydride (367 mg, 2.5 mmol, 25 equiv) were
charged to a microwave vial. The vial was evacuated and refilled
4
, Dibromide 3 (1.00 g, 0.799 mmol, 1 equiv), 3,9-bis(4,4,5,5-
tetramethyl-1,3,2-dioxaborolan-2-yl)perylene (402 mg, 0.797
mmol, 1 equiv), and SPhos Pd G2 (115 mg, 0.159 mmol, 0.2
equiv) were dissolved in 240 mL dioxane and heated to 80 °C. 25
mL (degassed) 2 M K PO (aq) was added to the solution and
allowed to stir over night. Dioxane was removed in vacuo and the
crude reaction mixture was dissolved in CH Cl and washed with
H O, brine, dried over Na SO and solvent removed in vacuo.
The crude residue was purified by flash chromatography (30%
EtOAc/hexanes) affording a yellow solid (147 mg, 17%). Note:
with N 3 times. 2-nitroethan-1-ol (225 mg, 0.29 mmol, 25 equiv)
2
was and the mixture was dissolved in 4 mL 1,2-Dichlorobenzne.
The vial was heated to 200 °C for 20 h and the mixture was
diluted with toluene and solvent was removed in vacuo. The
crude residue was purified by flash chromatography (10%
CH Cl /hexanes) affording a mixture of product and starting
3
4
2
2
2
2
2
2
4
material (25 mg, ratio 1.39:1, 55% yield). Spectral data matched
16
as previously reported.
,9-dibromoperylene : Following a modified literature procedure,
1
partial deprotection of the silyl ether was observed. H NMR
3
(600 MHz, CDCl ) δ 8.12 (d, J = 7.4 Hz, 2H), 8.02 (d, J = 7.8
3
perylene (5.90 g, 23.4 mmol, 1 equiv) was dissolved in 900 mL
benzene in a 2 L flask equipped with a base trap at 80 °C. The
mixture was allowed to cool to 35 °C (note-some perylene
Hz, 2H), 7.64 (d, J = 8.2 Hz, 2H), 7.33- 7.30 (m, 2H), 7.29 – 7.27
m, 6H), 7.23 – 7.10 (m, 16H), 6.33 (dd, J = 10.2, 2.4 Hz, 2H),
(
6
5
.21 (dd, J = 10.1, 2.4 Hz, 2H), 6.14 (dd, J = 10.1, 2.3 Hz, 2H),
.91 (dd, J = 10.1, 2.4 Hz, 2H), 2.10 (s, 2H), 1.24 (s, 2H), 1.04 (t,
precipitated out of solution) and Br (17.3 g, 109 mmol, 4.7
2
equiv) was added dropwise over 10 min and the reaction was
stirred at 35 °C for 1 hour then cooled to room temperature. The
precipitate was filtered and recrystallized 4x in 5/3
13
J = 7.9 Hz, 18H), 0.73 (q, J = 7.7 Hz, 12H). C NMR (151 MHz,
CDCl ) δ 143.4, 142.0, 140.3, 140.0, 139.9, 139.3, 135.6, 133.4,
1
1
6
3
32.6 (2), 131.1, 130.3, 129.8, 129.3, 128.6, 128.0, 127.5, 127.1,
26.6, 126.5, 126.2, 125.9, 120.2, 119.4, 72.4, 69.8, 29.7, 7.2,
aniline/toluene then washed with acetone affording an orange
1
solid (2.1 g, 26%) H NMR (600 MHz, CDCl ) δ 8.24-8.21 (m,
+
3
.5. MALDI-TOF (m/z) [M] calculated for C H O Si 1112.5;
74
72
6
2
2
H), 8.12 (dd, J = 8.4, 0.9 Hz, 2H), 8.03 (d, J = 8.1 Hz, 2H), 7.78
-
1
found 1112.2 IR (film, cm ): 3340, 2923, 1589, 1506, 1358
13
(d, J = 8.1 Hz, 2H), 7.59 (dd, J = 8.4, 7.5 Hz, 2H). C NMR (151
MHz, CDCl ) δ 133.2, 131.1, 130.9, 130.8, 129.6, 127.9, 127.5,
3
5
5
, Macrocycle 4 (118 mg, 0.106 mmol, 1 equiv) was dissolved in
mL THF at room temperature and TBAF (1 M in THF, 0.424
1
4
1
23.1, 121.4, 121.1. HRMS (CI+) (m/z): calculated for C H Br
20 10 2
-1
07.9149; found 407.9156 IR (film, cm ): 3047, 1931, 1846,
mmol, 4 equiv) was added. The reaction was stirred for 2 h and
then quenched with H O, diluted with THF, and washed with
brine. The organic layer was dried over Na SO and filtered
through a pad of silica eluting with 20% MeOH/CH Cl and
1
1
777, 1599 characteristic H peaks of minor isomer H NMR
2
(
600 MHz, CDCl ) δ 8.26 (d, J = 7.8 Hz, 2H), 7.98 (d, J = 8.2
3
2
4
Hz, 2H).
2
2
solvent removed in vacuo. Next, aqueous HCl (48 µL, 0.58
3
,9-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)perylene
mmol, 6.6 equiv) was added to a solution of SnCl2
·
2H O (65 mg,
2
3,9-dibromoperylene (1.00 g, 2.44 mmol, 1 equiv), B Pin (1.54
g, 6.06 mmol, 2.5 equiv), Pd(dppf)Cl (175 mg, 0.239 mmol, 0.1
2
2
0
.29 mmol, 3.3 equiv) in 8 mL THF. The solution was allowed to
2
stir for 15 min at room temperature. The solution was then
transferred via syringe to a flask containing the crude deprotected
macrocycle from above and allowed to stir overnight in the dark.
The reaction was quenched with 10% NaOH (aq) and extracted
equiv), and finely ground KOAc (1.41 g, 14.4 mmol, 6 equiv)
were combined in a dry flask. The flask was then evacuated and
backfilled with N 3 times. 25 mL of toluene was added to the
2
mixture and the flask was heated to 80 °C and allowed to stir
overnight. The mixture was cooled to room temperature then
filtered through a pad a celite eluting with ethyl acetate. Solvent
was removed in vacuo and the crude residue was purified via
with CH Cl . The organic layer was washed with brine, dried
2
2
with Na SO , and solvent removed in vacuo. The crude residue
2
4
was purified via flash chromatography (40% CH Cl /hexanes)
2
2
1
affording a red solid (47 mg, 68%). H NMR (600 MHz, CDCl )
3
flash chromatography (5% EtOAc/Hexanes) affording a yellow
1
δ 8.14 (d, J = 8.2 Hz, 2H), 8.02 (d, J = 7.4 Hz, 2H), 7.73 (d, J =
solid (370 mg, 31%) H NMR (600 MHz, CDCl ) δ 8.67 (dd, J =
3
8
7
.0 Hz, 2H), 7.66 – 7.48 (m, 12H), 7.48 – 7.38 (m, 10H), 7.36-
.33 (m, 6H), 7.23 (d, J = 8.8 Hz, 4H). C NMR (151 MHz,
8
.4, 1.0 Hz, 2H), 8.25 (m, 2H), 8.18 (d, J = 7.6 Hz, 2H), 8.06 (d,
13
13
J = 7.6 Hz, 2H), 7.53 (dd, J = 8.4, 7.5 Hz, 2H), 1.42 (s, 24H).
C
CDCl ) δ 140.1, 139.5, 138.7, 138.2, 138.0, 137.7, 137.5, 136.9,
3
NMR (151 MHz, CDCl ) δ 138.3, 136.3, 134.4, 131.0, 129.1,
3
1
1
31., 131.3, 130.4, 129.6, 129.1, 128.7, 128.5, 128.1, 127.5,
27.4, 127.1, 127.0, 126.4, 126.2, 121.6, 119.2. MALDI-TOF
1
28.4, 126.8, 120.8, 119.5, 83.7, 25.0. HRMS (ES+) (m/z):
+
[
M+Na] calculated for C H B O Na 527.2552 found 527.2568
32 34 2 4
-1 1
+
-
(
m/z) [M] calculated for C H 782.3; found 782.1 IR (film, cm
62 38
IR (film, cm ): 2974, 1588, 1506, 1370. H peaks of minor
1
1
)
: 3024, 2923, 1591, 1485, 1387, 1262
isomer H NMR (600 MHz, CDCl ) δ 8.64 (d, J = 8.3 Hz,
3
2
H), 8.22-8.20 (m, 4H)
8
, 5 (9.0 mg, 0.011 mmol, 1 equiv) and phthalic anhydride (43
mg, 0.29 mmol, 25 equiv) were charged to a microwave vial. The
Acknowledgements
vial was evacuated and refilled with N 3 times. 2-nitroethan-1-ol
2
(
91 mg, 0.29 mmol, 25 equiv) was added and the mixture was
dissolved in 350 µL 1,2-Dichlorobenzne. The vial was heated to
00 °C for 20 h and the mixture was diluted with CH Cl and
Financial support was provided by the National Science
Foundation (CHE-1255219), the Sloan Foundation, and the
University of Oregon.
2
2
2
solvent was removed in vacuo. The crude residue was purified by

5
ACCEPTED MAN
1
U
1.
S
S
C
eg
R
aw
I
a, Y.; Fukazawa, A.; Matsuura, S.; Omachi, H.;
P
T
Yamaguchi, S.; Irle, S.; Itami, K. Org. Biomol. Chem.
2012, 10, 5979–5984.
Supplementary Data
1
13
12. Berlman, I. B. Handbook of Fluorescence Spectra of
Aromatic Molecules; Elsevier, 1971.
H & C spectra, computational details, and photophysical
data are available in the Supplementary Data.
1
3. Darzi, E. R.; Sisto, T. J.; Jasti, R. J. Org. Chem. 2012, 77,
624–6628.
6
References
1
.
(a) Tasis, D.; Tagmatarchis, N.; Bianco, A.; Prato, M.
Chem. Rev. 2006, 106, 1105–1136. (b) Liu, B.; Wang, C.;
Liu, J.; Che, Y.; Zhou, C. Nanoscale 2013, 5, 9483–9502.
14. Segawa, Y.; Fukazawa, A.; Matsuura, S.; Omachi, H.;
Yamaguchi, S.; Irle, S.; Itami, K. Org. Biomol. Chem.
2012, 10, 5979–5984.
(c) Dai, H. Acc. Chem. Res. 2002, 35, 1035–1044. (d)
1
5. Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen,
Fennimore, A. M.; Yuzvinsky, T. D.; Han, W.-Q.;
Fuhrer, M. S.; Cumings, J.; Zettl, A. Nature 2003, 424,
R. K.; Timmers, F. J. Organometallics 1996, 15, 1518–
1
520.
4
2
2
08–410. (e) Hong, S.; Myung, S. Nat. Nanotechnol.
007, 2, 207–208. (f) Cumings, J.; Zettl, A. Science.
000, 289, 602–604.
1
6. Shen, H.-C.; Tang, J.-M.; Chang, H.-K.; Yang, C.-W.;
Liu, R.-S. J. Org. Chem. 2005, 70, 10113–10116.
2
3
.
.
(a) Wang, H.; Yuan, Y.; Wei, L.; Goh, K.; Yu, D.; Chen,
Y. Carbon N. Y. 2015, 81, 1–19. (b) Liu, J.; Hersam, M.
C. MRS Bull. 2011, 35, 315–321. (c) Haddon, R. C.;
Sippel, J.; Rinzler, A. G.; Papadimitrakopoulos, F. MRS
Bull. 2011, 29, 252–259. (d) Hou, P.-X.; Liu, C.; Cheng,
H.-M. Carbon N. Y. 2008, 46, 2003–2025.
Sanchez-Valencia, J. R.; Dienel, T.; Gröning, O.;
Shorubalko, I.; Mueller, A.; Jansen, M.; Amsharov, K.;
Ruffieux, P.; Fasel, R. Nature 2014, 512, 61–64. (b)
Omachi, H.; Nakayama, T.; Takahashi, E.; Segawa, Y.;
Itami, K. Nat. Chem. 2013, 5, 572–576. (c) Smalley, R.
E.; Li, Y.; Moore, V. C.; Price, B. K.; Colorado, R.;
Schmidt, H. K.; Hauge, R. H.; Barron, A. R.; Tour, J. M.
J. Am. Chem. Soc. 2006, 128, 15824–15829.
4
.
(a) Fort, E. H.; Jeffreys, M. S.; Scott, L. T. Chem.
Commun. 2012, 48, 8102–8104. (b) Fort, E. H.; Scott, L.
T. J. Mater. Chem. 2011, 21, 1373–1381. (c) Fort, E. H.;
Scott, L. T. Angew. Chem. Int. Ed. 2010, 49, 6626–6628.
(d) Fort, E. H.; Donovan, P. M.; Scott, L. T. J. Am. Chem.
Soc. 2009, 131, 16006–16007.
5
6
.
.
Clar, E.; Zander, M. J. Chem. Soc. 1957, 4616-4619.
For computational studies see: Li, H.-B.; Page, A. J.; Irle,
S.; Morokuma, K. J. Am. Chem. Soc. 2012, 134, 15887–
1
5896.
7
8
.
.
(a) Golder, M. R.; Jasti, R. Acc. Chem. Res. 2015, 48,
5
4
4
57–566. (b) Darzi, E. R.; Jasti, R. Chem. Soc. Rev. 2015,
4, 6401–6410. (c) Lewis, S. E. Chem. Soc. Rev. 2015,
4, 2221–2304. (d) Jasti, R.; Bertozzi, C. R. Chem. Phys.
Lett. 2010, 494, 1–7.
For recent examples see: Darzi, E. R.; Hirst, E. S.;
Weber, C. D.; Zakharov, L. N.; Lonergan, M. C.; Jasti, R.
ACS Cent. Sci. 2015, 1, 335–342. (b) Evans, P. J.; Darzi,
E. R.; Jasti, R. Nat. Chem. 2014, 6, 404–408. (c) Li, P.;
Sisto, T. J.; Darzi, E. R.; Jasti, R. Org. Lett. 2014, 16,
1
82–185. (d) Xia, J.; Golder, M. R.; Foster, M. E.; Wong,
B. M.; Jasti, R. J. Am. Chem. Soc. 2012, 134, 19709–
9715.
1
9
1
.
Uchida, T.; Kozawa, K.; Nagao, Y.; Misonoo, T. Bull.
Chem. Soc. Jpn. 1979, 52, 1547–1548.
0. Patel, V. K.; Kayahara, E.; Yamago, S. Chem. Eur. J.
015, 21, 5742–5749.
2