Meso-Fused Carbatriphyrins(2.1.1) and Its Organo Phosphorus(V) Complex

Article abstract of DOI:10.1021/acs.joc.9b01015

The first examples of phlorin analogues of meso-fused carbatriphyrins(2.1.1) and organo P(V) complex of one of the meso-fused carbatriphyrins were obtained by adopting a premodification strategy starting with fluorene as a fused polyaromatic precursor ove

Full text of DOI:10.1021/acs.joc.9b01015

Subscriber access provided by Nottingham Trent University
Article
Meso-Fused Carbatriphyrins(2.1.1) and its Organo phosphorus(V) Complex
Ankit Kumar, Kishor Gulab Thorat, Avisikta Sinha, Raymond John Butcher, and Mangalampalli Ravikanth
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.9b01015 • Publication Date (Web): 02 Jul 2019
Downloaded from http://pubs.acs.org on July 3, 2019
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a service to the research community to expedite the dissemination
of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in
full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully
peer reviewed, but should not be considered the official version of record. They are citable by the
Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore,
the “Just Accepted” Web site may not include all articles that will be published in the journal. After
a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web
site and published as an ASAP article. Note that technical editing may introduce minor changes
to the manuscript text and/or graphics which could affect content, and all legal disclaimers and
ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or
consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W.,
Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 11
The Journal of Organic Chemistry
1
2
3
4
5
6
7
Meso-Fused Carbatriphyrins(2.1.1) and its Organo phosphorus(V)
Complex
Ankit Kumar,† Kishor G. Thorat,† Avisikta Sinha,† Ray J. Butcher‡ and Mangalampalli Ravikanth*†
8
9
†
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai - 400076, India
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
‡
Department of Chemistry, Howard University, 525 College Street NW, Washington, D.C 20059, USA
ABSTRACT: The first examples of phlorin analogues of meso-fused carbatriphyrins(2.1.1) and organo P(V) complex of one of the meso-
fused carbatriphyrins were obtained by adopting premodification strategy starting with fluorene as fused polyaromatic precursor over
sequence of steps. The meso-fused carbatriphyrins(2.1.1) were obtained as their nonaromatic phlorin analogues owing to the unstable nature
of the fully conjugated meso-fused carbatriphyrins(2.1.1). The organo P(V) complex of one of the meso-fused carbatriphyrins was prepared
by treating phlorin analogue of carbatriphyrin(2.1.1) with PCl3 in toluene/triethylamine at reflux for 1 h. The P(V) complex of the meso-
fused carbatriphyrin(2.1.1) was found to be moderately aromatic and the resulting global conjugation pathway in P(V) complex significantly
alters the aromaticity of the fluorene unit. The nonaromatic nature of the phlorin analogues of the meso-fused carbatriphyrin(2.1.1) and the
moderately aromatic nature of its P(V) complex were supported by X-ray cystallography, absorption spectroscopy, NMR studies together
with NICS, AICD and HOSE calculations.
tuned by replacing one of the pyrrole rings with other five or six
INTRODUCTION
membered heterocycles such as thiophene21 and furan22 etc. A
perusal of literature reveals that some attempts have been made
Triphyrins(2.1.1)1–3 II are the immediate higher analogues of
in this direction and few modified triphyrins(2.1.1) such as III
triphyrins(1.1.1)4–7 which can be obtained only as their boron(III)
have been successfully synthesized and explored their
complexes I and popularly know as subporphyrins8–12 (Figure 1).
properties.23–25 One of the interesting modification is introducing
Thus, triphyrins(2.1.1) II are tripyrrolic macrocycles in which
carbon donor ring such as benzene in place of pyrrole and the
three pyrroles are connected via four meso carbons.
resulted carbatriphyrins(2.1.1) IV will be expected to show
Triphyrins(2.1.1) are contracted porphyrinoids13 having one less
distinct properties due to different conjugation pathways and may
pyrrole ring compared to tetrapyrrolic porphyrins.14,15 Because of
also form unique organometallic complexes. To the best of our
one less pyrrole ring, triphyrins(2.1.1) II have reduced number of
knowledge, no carbatriphyrins(2.1.1) such as IV are reported so
coordinating donor atoms and cavity size compared to porphyrins.
far which could be due to lack of proper synthetic protocols and
However, the triphyrins(2.1.1) II are aromatic 14electron
their inherent instability. We initially attempted to prepare
carbatriphyrin(2.1.1) IV by McMurry coupling of diacylated
benzitripyrrane under different reaction conditions but we were
unsuccessful in isolating the stable carbatriphyrin(2.1.1) IV. At
this stage, we thought that if we use fused polyaromatic
hydrocarbon in place of benzene, we anticipated that different
conjugation pathways may stabilize the resulting meso-fused
systems and readily forms metal complexes.16–19 The tripyrrolic
triphyrins(2.1.1) can be readily prepared by (2+1) methodology.
Recently, we developed a straightforward method for the
synthesis of meso-tetra aryl triphyrins(2.1.1) II (Figure 1) using
readily available precursors.20 Similar to the porphyins, the
electronic properties of triphyrins(2.1.1) can also be further
carbatriphyrin V. We chose fluorene as a fused polyaromatic
hydrocarbon to synthesize the desired meso-fused
carbatriphyrin(2.1.1) 1. However, our attempts led to the
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Ar
O
N
B
N
Cl
N
N
NH
N
N
NH
Ar
N
N
N
N
formation
of
phlorin
analogues
of
meso-fused
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Ar
Fused-
Subporphyrin
Triphyrin(2.1.1) Triphyrin(2.1.1)
carbatriphyrin(2.1.1) 2-3 instead of 1. Interestingly, the treatment
of phlorin analogue of meso-fused carbatriphyrin(2.1.1) 2 with
PCl3 resulted in formation of fully conjugated moderately
aromatic P(V) complex of meso-fused carbatriphyrin(2.1.1) 2.PO.
Carbatriphyrin(2.1.1)
III
I
II
IV
Carbatriphyrin(2.1.1)
V
OH
O
P
S
R
S
S
N
N
N
HN
N
N
RESULTS AND DISCUSSION
C6F5
1
C6F5
C6H5
2
:
3
:
2.PO
The phlorin analogues of meso-fused carbatriphyrins(2.1.1) 2 and
3 were prepared over a sequence of steps as shown in Scheme 1.
In the first step, the fluorene was subjected to Friedel-Crafts
benzoylation to afford mono-benzoylated fluorenes 4 and 5 which
R = H
R = CH3
Figure 1. Structures of subporphyrins and triphyrins.
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 2 of 11
1
2
3
4
5
R
O
R
R
R
Cl
i) n-BuLi, THF
NaBH4
6
7
8
9
HO
AlCl3
ii) 2-thiophene
carboxaldehyde
THF/MeOH
O
HO
HO
10:1
DCE, reflux 4 h
6
R = -H
R = -CH3
:
(99%)
(99%)
4
R = -H
R = -CH3
:
(57%)
(58%)
0 oC, 3 h
S
7
:
5
:
8
R = -H
R = -CH3
:
(38%)
(36%)
9
:
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
pyrrole
DCE
reflux 8 h
BF3·OEt2
R
HO
NH
i) BF3·OEt2
C6F5-CHO
R
O
N
PCl3, TEA
P
S
N
H
toluene, reflux
1 h
S
NH
N
N
ii) DDQ
S
C6F5
2.PO
C6H5
10
11
R = -H
R = -CH3
:
:
(51%)
(48%)
(48%)
2
3
R = -H
R = -CH3
:
:
(31%)
(30%)
i) BF3·OEt2
C6F5-CHO
ii) DDQ
S
N
N
C6F5
1
Not found
Scheme 1. Synthesis of meso-fused carbatriphyrins(2.1.1) 1, 2, 3 and 2.PO.
were then reduced with NaBH4 in THF/CH3OH at room
temperature to the corresponding mono-ols 6 and 7. In the next
step, the mono-ols 6 and 7 were treated with n-BuLi in THF
followed by 2-thiophene carboxaldehyde at 0 °C for 3 h and the
crude compounds were purified by column chromatography to
afford the corresponding diols 8 and 9 in 36-38% yields.
Appropriate diols 8 and 9 were treated with excess pyrrole in the
presence of catalytic amount of BF3·OEt2 followed by column
chromatographic purification to afford corresponding tripyrranes
10 and 11 in 48-51% yields.
to further oxidize the phlorin analogues 2/3 to the fully conjugated
meso-fused carbatriphyrins(2.1.1) 1 (Figure 1) were unsuccessful.
Furthermore, the phlorin analogue of meso-fused
carbatriphyrin(2.1.1)
2
was treated with PCl3 in
toluene/triethylamine at reflux for 1 h and we noticed a clear
colour change from blue to reddish orange as the reaction
proceeds. TLC analysis showed the disappearance of spot
corresponding to compound 2 and appearance of new less polar
spot and the absorption spectral studies showed clear changes in
the absorption spectra supporting a possibility of phosphorus
insertion into the macrocycle 2. The crude compound was
subjected to silica gel column chromatographic purification and
afforded orange solid which showed the molecular ion peak at
701.0870 in HR-MS indicating the formation of organo P(V)
complex 2.PO. The macrocycles 2, 3 and 2.PO and all
intermediate compounds were characterized in detail by HR-MS
The appropriate tripyrranes 10 and 11 were condensed
with pentafluorobenzaldehyde in CH2Cl2 in the presence of
catalytic amount of BF3·OEt2 for 1 h under inert atmosphere at
room temperature followed by oxidation with DDQ in open air
for additional 1 h. TLC analysis showed one major polar blue spot
corresponding to the phlorin analogue of meso-fused
carbatriphyrin(2.1.1) 2 and 3 having one hydroxyl group at meso-
sp3 carbon (vide-infra) along with one or two less polar spots
corresponding to the unidentified compounds. The crude
compound was subjected to silica gel column chromatographic
purification and afforded phlorin analogue of meso-fused
carbatriphyrin(2.1.1) 2/3 as blue solid in ~30% yield. Attempts
1
and NMR techniques (Figures S1-S43). The comparison of H
NMR spectra of compound 2 with its P(V) complex 2.PO are
shown in Figure 2. All the resonances in 1H NMR spectrum of 2
were identified and assigned based on position, coupling constant
and cross-peak correlations in COSY and NOESY spectra
1
(Figures S33-S38). In H NMR of compound 2, the meso-OH
resonance appeared at 2.99 ppm showed NOESY
ACS Paragon Plus Environment

Page 3 of 11
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
h
g
i
f
c
j
n m
o
a
b
d
OH
e
(a)
OH
mj
Sa
e
l
k
p
l
h
P
o
f
n
k
N
HN
c
i
g
NH
b
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
b
F
F
F
F
gF
f,o,n
m
h
i
f
e
a
m j
e
h
j
k,l,i
l
o
b
d
O
N
(b)
c
P
Sa
n
k
N
c
g
b
F
b
F
F
F
F
Figure 2. (a) and (b) Comparison of 1H NMR spectra of compound 2 and 2.PO.
correlation with inner pyrrole NH proton appeared at 14.60 ppm.
Both meso-OH and inner NH protons showed NOESY correlation
with type p proton of fluorene moiety appeared at 8.46 ppm. The
other macrocyclic protons as well as protons of meso-substituents
were also identified based on these cross-peak correlations in 2D
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
confirmed their expected chemical composition and
connectivities. In compound 2, the substituents on meso sp2
carbons (C10 and C15) were oriented in almost orthogonal
fashion (70-80°) with respect to the mean plane defined by 13
inner core atoms. Furthermore, the bond length analysis (C9-C10
1.37 Å, C10-C11 1.46 Å) supports that the π-delocalization was
effective in both independent dipyrrin and fluorene units but was
disrupted at meso-sp3 carbon (C20). Thus, compound 2 exhibits
nonaromatic character which was in line with NMR spectral
studies.
1
NMR spectra. In H NMR (Figure 2b) spectrum of compound
2.PO, the inner type p proton and inner NH along with meso-OH
proton resonances were absent supporting the P(V) insertion into
2 to form moderately aromatic 2.PO. The β-pyrrole protons of
2.PO experienced downfield shifts compared to compound 2.
1
However, the close inspection of H NMR of compounds 2 and
2.PO indicates that the compounds are not isomerically pure but
present as mixture of non-separable diastereomers. For example,
the type g proton in compound 2 appeared as two doublets due to
presence of diastereomers. All other resonances in compounds 2
and 2.PO are either broadened or appeared as overlapping
resonances supporting the presence of diastereomers. This was
also supported by two close resonances at -11.61 and -11.74 ppm
in 31P NMR spectrum of 2.PO (Figure S41).
In the compound 2.PO, the P(V) was bound to two
pyrrole nitrogen’s, one fluorene carbon and one axial oxygen to
form organo P(V) complex. The bond angles around phosphorus
atom [N1-P-N2, 96.26˚; N2-P-C1, 98.52˚; N1-P-C1, 109.21˚; N1-
P-O, 114.42˚; N2-P-O, 118.55˚; C1-P-O, 117.05˚] suggests a
distorted trigonal pyramidal geometry. The phosphorus atom was
situated at 0.835 Å above the mean plane of the macrocycle. All
three meso substituents were out of plane with respect to the plane
of the macrocycle and deviated from the mean plane by 48-88°.
The bond lengths (P-N1 1.650 Å, P-N2 1.658 Å, P-C1 1.748 Å
and P-O 1.468 Å) (Table S5) showed a close match with other
reported phosphorus complexes of macrocycles such as N-fused
porphyrins.26,27 The bond length analysis (C9-C10 1.34 Å, C10-
C11 1.43 Å, C2-C20 1.47 Å and C20-C21 1.36 Å) reveals that the
-delocalization was effective on all over the macrocyclic core
and macrocycle 2.PO exhibits aromatic features. Thus, it is very
interesting to note that the phosphorus insertion into the
macrocycle 2 switches the non-aromatic macrocycle 2 into the
aromatic macrocycle 2.PO.
The molecular structures of 2 and 2.PO (Figure 3) were
elucidated by single-crystal X-ray crystallography. The single
crystals for X-ray analysis were obtained by slow evaporation of
an n-hexane/chloroform. The relevant crystallographic data of 2
and 2.PO are presented in (Tables S4-S6). The compound 2
1
crystallizes in triclinic system with P space group having four
molecules in a unit cell. Whereas, the compound 2.PO
crystallizes in monoclinic system with space group I2/c having
eight molecules in a unit cell. The X-ray single crystal structures
of the compounds 2 and 2.PO
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 4 of 11
1
2
3
4
5
6
7
8
9
OH
C
C
C
S1/C22
C
S1/C22
S1/C22
S1/C22
S1/C22
B
A
B
A
B
C2
C20
B
A
A
C2
C20
N2
C10
C9
C9
C1
N2
O1
O1
C1
C10
N1
C15
C10
C10
C20
P1
N2
C15
P1
C20
N1
N1
N1
N2
S1/C22
OH
S1/C22
S1/C22
C15
C15
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
OH is above the plane
Isomer 1; S1 and OH are cis
Isomer 2; S1 and OH are trans
OH is below the plane
Isomer 3; S1 and OH are cis
Isomer 4; S1 and OH are trans
PO is facing away from us
Isomer 3; S1 and PO are cis
Isomer 4; S1 and PO are trans
PO is facing towards us
Isomer 1; S1 and PO are cis
Isomer 2; S1 and PO are trans
Figure 3. Single-crystal X-ray structures as a different isomeric forms for the compounds 2 and 2.PO obtained from their
respective unit cell.
Furthermore, a close inspection of crystal packings of
the compounds 2 and 2.PO reveals the presence of more than one
isomeric form for each 2 and 2.PO. For instance, the compound
2 possesses one sp3 chiral center and in addition to that, the free
rotation of thiophene ring (present on meso C10) was inhibited
due to steric hindrance imparted by benzene ring (marked as ‘C‘)
of fluorene moiety. This resulted in the formation of two pairs of
diastereomers which supports our claim of presence of more than
one isomer for the compound 2. Thus, it was possible that the PO
can insert from either side of the ‘S‘of the thiophene ring which
resulted in the formation of pair of diastereomers for the
compound 2.PO as shown in Figure 3. All these forms for
compounds 2 and 2.PO were extracted from their respective unit
cell (Figures S47-S50).
The comparison of absorption spectra and redox waves
of 2 and 2.PO are presented in Figure 4. The macrocycle 2
showed one broad featureless band at 624 nm with a shoulder at
615 nm and two more absorption bands in higher energy region
at 367 and 344 nm supporting the nonaromatic nature of
macrocycle (Figure 4a). Upon protonation of
2 with
trifluoroacetic acid, the color of the solution was changed from
blue to green and the resulted protonated compound 2.H+ showed
four bands at 333, 393, 608 and 749 nm. The PO complex 2.PO
showed four to five Q-type of absorption bands in the region of
450-800 nm and two Soret type bands at 345 and 415 nm (Figure
4a, Table S1). These absorption features of 2.PO are more in line
with 14 triphyrin(2.1.1).1,20,28 Furthermore, the absorption
features of 2.PO were in agreement with NMR and X-ray data
supporting the aromatic nature of complex 2.PO. The redox
properties of compounds 2, 3 and 2.PO were investigated using
cyclic voltammetry and differential pulse voltammetry.
Comparison of cyclic voltammogram along with differential
pulse voltammogram of compounds 2 and 2.PO is shown in
Figure 4b. The compound 2 showed two irreversible oxidations
at 1.21 and 1.44 V and four reductions at -0.67, -1.10, -1.14 and -
1.68 V (Table S2) indicating the electron deficient nature of the
macrocycle. However, the 2.PO showed easier oxidations and
harder reductions compared to 2 (Figure 4b).
Figure 4. (a) Absorption spectra of 2 (blue line) and 2.PO
(red line) recorded in toluene (1.5×10-5 M). (b) Comparison
cyclic voltammogram (solid line) and differential pulse
voltammogram (dotted line) of 2 (blue line) and 2.PO (red
line) recorded in CH2Cl2 using 0.1 M TBAP as the
supporting electrolyte recorded and a saturated calomel
electrode (SCE) as the reference electrode at 50 mVs-1
scan rate.
To further probe the electronic structures of the
compounds 2 and 2.PO, density functional theory (DFT)
calculations were carried out at B3LYP/6-31G(d,p) level. The
ground state optimized geometries showed similar structural
ACS Paragon Plus Environment

Page 5 of 11
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
10
11
12
nonaromatic nature of the compound 2 was supported by weakly
negative NICS value estimated at center of the core of the
macrocycle 2 (NICS(0) = -1.34 ppm) (Figure S53). On the other
hand, the moderate aromatic nature of 2.PO was further
supported by negative NICS value (NICS(0) = -4.84 ppm)
obtained at central point of π-conjugation pathway. Interestingly,
three NICS(0) values at the center of fluorene ring (that is A, B
and C) in 2.PO were estimated to be -7.20, -9.81 and -12.65 ppm,
respectively, and are different from that of original fluorene ring
(NICS(0) = -8.98 and +0.62 ppm for the six and five membered
rings, respectively) as shown in Figure S53. This indicates the
presence of the canonical conjugation circuit across the boundary
of the local fluorene subunit in 2.PO and suggest the possibility
of the presence of 18 π and 22 π-conjugation pathways with
different contributions as depicted in Figure 6. To investigate the
contribution of each of the possible canonical form, the harmonic
oscillation stabilization energy (HOSE)29 calculations were
carried on DFT optimized structure (Table S7). The HOSE
indices indicated that the 18 π system has lower energy
(HOSE=85.60 kJ/mol) compared to that of 22 π system
(HOSE=120.74 kJ/mol). This indicates that the 18 π system is the
major contributor with ~59% contribution whereas the 22 π
system has ~41% contribution (Figure 6). Thus, the 18 π
conjugated pathway in 2.PO is most likely, though further
structural investigations needs to be done in future.
Ar
+2H
OH
Ar
Ar
S
H
H
N
H
-2H
S
S
N
N
H
N
N
N
Ar
IV
Ar
2
2
Ar
IV'
1
1’
Unstable
strong electronic
repulsions
Unstable
Strong steric
crowding
Stabilized
Intramolecular
H-bonding
Scheme 2. Summary of the preferential formation of the
phlorin analogue
carbatriphyrin 1 or 1’.
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
2
over fully oxidized/conjugated
parameters for the compounds 2 and 2.PO as those obtained by
X-ray studies. The formation of phlorin analogue 2 over its fully
conjugated forms 1 and 1’ was explained on the basis of total
energies of their ground state optimized geometries (Scheme 2
and Figure S51). From Scheme 2, it is seen that the forms 1 and
1’ are energetically highly unstable compared to compound 2.
This can be attributed to strong electronic repulsions between the
two lone pairs present on two imine N’s in 1 and severe steric
crowding due to three inner H’s in 1’ whereas, the compound 2
attains stability due to presence of intramolecular H-bonding
(Scheme 2). We noticed that, the fully oxidized form 1 or 1’ is not
isolable and immediately gets converted in to its phlorin analogue
2. The form 1 is expected to be 20π system with antiaromatic
nature whereas the form 1’ is 22π system with aromatic in nature.
The S0 optimized geometries indicated that the overall structures
of 1 and 1’ were found to be distorted due to electronic repulsions
and steric interactions, respectively (Figure S51). Due to this, the
form 1 was found to be weakly antiaromatic whereas the form 1’
was found to be weakly aromatic as estimated by nucleus
independent chemical shifts NICS(0) calculations (Figure S53;
for form 1 NICS(0) = +5.92 ppm and for 1’ NICS(0) = -4.12 ppm).
The analysis of frontier molecular orbitals (FMOs) of the
compound 2.PO shows that both HOMO and LUMOs were
located on macrocyclic core including entire fluorene subunit
with uneven distribution of the orbitals. This supports the weak
aromatic nature of the 2.PO (Figure S52). The continuous
clockwise ring current in AICD (anisotropy induced current
density) plot of the compound 2.PO also supports its aromatic
nature. Whereas, the clockwise ring current which shows
disruption at meso sp3 center supports the nonaromatic nature of
the compound 2 (Figure 5). Also, the
C
C
B
B
A
A
S
S
O
O
P
P
N
N
N
N
F
F
F
F
F
F
F
F
F
F
22 
~41%
18 
~59%
2.PO-b
2.PO-a
Figure 6. Possible canonical structures of the compound
2.PO
CONCLUSIONS
In conclusion, we adopted unique approach to synthesize the first
examples of stable carbatriphyrins(2.1.1). Our studies showed
that carbatriphyrins(2.1.1) can be obtained as non-aromatic
phlorin analogue in free base form but can be converted to
completely conjugated moderately aromatic organo PO complex
of carbatriphyrin(2.1.1). The fluorene unit in PO complex has
coplanar geometry, thus significant alteration in local aromaticity
of the benzene rings of the fluorene moiety is noted. The
computational strategies such as NICS, AICD and HOSE were
highly useful in understanding the aromaticity characteristics and
probable canonical pathways in the P(V) complex of the meso-
fused carbatriphyrins(2.1.1).
2.PO
Figure 5. AICD plots for the compounds 2 and 2.PO.
2
EXPERIMENTAL SECTION
The chemicals such as BF3·OEt2, trifluoroacetic acid (TFA), and
2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) were used as
obtained from Aldrich. All other chemicals used for the synthesis
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 6 of 11
1
2
3
were reagent grade unless otherwise specified. Column
basis set 6-31G(d,p),35-40 was used to optimizes the geometries of
4
5
6
7
8
9
chromatography was performed on silica (60-120 and 100-200
mesh), neutral alumina and basic alumina. 1D, 2D, 13C, 19F and
31P NMR spectra were recorded in CDCl3 on Bruker 400 and 500
MHz instruments. The frequency for 13C nucleus is 100 MHz and
125.7 MHz. Tetramethylsilane [Si(CH3)4] was used as an internal
standard for 1H and 13C NMR. Absorption spectra were obtained
with Cary series UV-Vis-NIR and UV 3600 Shimadzu
spectrophotometer. Cyclic Voltammetric studies were carried out
with BAS electrochemical system utilizing the three electrode
configuration consisting of a Glassy carbon (working electrode),
platinum wire (auxiliary electrode) and saturated calomel
(reference electrode) electrodes. The experiments were done in
dry CH2Cl2 using 0.1 M tetrabutylammonium perchlorate
(TBAP) as supporting electrolyte. Half wave potentials were
measured using DPV (differential pulse voltammetry) and also
calculated manually by taking the average of the cathodic and
anodic peak potentials. All potentials were calibrated versus
saturated calomel electrode by the addition of ferrocene as an
internal standard, taking E1/2 (Fc/Fc+) = 0.42 V vs SCE. All the
solutions were purged prior to electrochemical and spectral
measurements with argon gas. The high resolution mass spectra
(HRMS) were recorded with a Bruker maxis Impact and Q-Tof
micro mass spectrometer using positive mode ESI methods for
acetonitrile/methanol solutions. For UV-vis the stock solution of
all compounds (5×10-4 M) were prepared by using HPLC grade
toluene solvent.
the fluorene meso-fused carbatriphyrins(2.1.1) 2 and 2.PO in
their ground (S0) states. The minimum energies surfaces of the
optimized
geometries
of
the
fluorene
meso-fused
carbatriphyrins(2.1.1) 2 and 2.PO were verified by vibrational
analyses, and no imaginary frequencies were found.
(9H-fluoren-2-yl)(phenyl)methanone (4):
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Friedel-Crafts reaction conditions were used to synthesize the
compound 4. Fluorene (3.0 g, 18.05 mmol) and AlCl3 (3.6 g,
27.07 mmol) in 1,2-dichloroethane (70 mL) was purged with N2
gas for 5 min. Benzoyl chloride (2.7 ml, 23.46 mmol) was added
and the resulting mixture was stirred under reflux for 4 h. The
solution was cooled to room temperature and quenched by
addition of saturated aqueous NH4Cl. The resulting mixture was
extracted with CH2Cl2, dried over Na2SO4 and the solvent was
removed under vacuum using rotary evaporator. The crude
compound was purified by silica gel column chromatography
using petroleum ether/EtOAc (9:1) to afford 4 in 57.3% yield (2.8
1
g); H NMR (400 MHz, CDCl3) δ 8.03 (s, 1H), 7.90 - 7.79 (m,
5H), 7.61 (t, J = 6.7 Hz, 2H), 7.51 (t, J = 7.5 Hz, 2H), 7.46 - 7.35
(m, 2H), 3.98 (s, 2H); 13C{1H} NMR (101 MHz, CDCl3) δ 196.7,
145.9, 144.4, 143.0, 140.5, 138.2, 135.8, 132.1, 129.9, 129.6,
128.2, 127.9, 127.0, 126.8, 125.2, 120.8, 119.4, 77.3, 77.0, 76.6,
36.9; HRMS calcd for (C20H14NaO): 293.0937 (M + Na)+, found
293.0935 (M + Na)+.
(9H-fluoren-2-yl)(p-tolyl)methanone (5): We have used above
mention procedure to synthesize compound 5 in 58.4% (3.0 g)
X-ray crystal structure analysis: Single-crystal X-ray structure
analysis was performed on a Rigaku Saturn 724 diffractometer
that was equipped with a low-temperature attachment. Data were
collected at 100 K using graphite-monochromated Mo-Kα
radiation (λα= 0.71073 Å) by ω-scan technique. The data were
reduced by using Crystal Clear-SM Ex-pert 2.1 b24 software. The
structures were solved by direct methods and refined by least-
squares against F2 utilizing the software packages SHELXL-9730,
SIR-9231, and WINGX.32 All non-hydrogen atoms were refined
anisotropically. The X-ray data for the meso-fused
carbatriphyrins(2.1.1) 2 and 2.PO were collected on a Bruker
1
yield; H NMR (500 MHz, CDCl3) δ 7.97 (d, J = 34.0 Hz, 1H),
7.92 – 7.81 (m, 3H), 7.76 (d, J = 6.8 Hz, 2H), 7.58 (dd, J = 23.0,
7.0 Hz, 1H), 7.48 – 7.35 (m, 2H), 7.31 (d, J = 7.1 Hz, 2H), 3.95
(d, J = 19.2 Hz, 2H), 2.44 (d, J = 20.7 Hz, 3H); 13C NMR (126
MHz, CDCl3) 13C{1H} NMR (126 MHz, CDCl3) δ 196.6, 145.7,
144.4, 143.0, 142.9, 140.6, 136.2, 135.4, 130.2, 129.5, 128.9,
127.9, 127.0, 126.7, 125.2, 120.8, 119.3, 36.9, 21.6; HRMS calcd
for (C21H16NaO): 307.1093 (M + Na)+, found 307.1098 (M +
Na)+.
Kappa CCD diffractometer equipped with
a
graphite-
(9H-fluoren-2-yl) (phenyl)methanol (6): A sample of 4 (2.0 g,
7.40 mmol) was reduced by NaBH4 (1.14 g, 30.2 mmol) in THF/
methanol (10:1) the resulting mixture was stirred under N2 for 30
min. The solution was quenched by addition of saturated aqueous
NH4Cl, extracted with diethyl ether, dried over Na2SO4 and
concentrated by rotary evaporator. The crude compound was
purified by silica gel column chromatography using petroleum
ether/EtOAc (8:2) to afford 6 in 99.2% Yield (2.0 g). 1H NMR
(400 MHz, CDCl3) δ 7.76 (t, J = 7.8 Hz, 2H), 7.57 (s, 1H), 7.53
(d, J = 7.4 Hz, 1H), 7.47 - 7.33 (m, 6H), 7.33 - 7.27 (m, 2H), 5.94
(s, 1H), 3.87 (s, 2H), 2.26 (s, 1H); 13C{1H} NMR (101 MHz,
CDCl3) δ 143.4, 142.4, 128.5, 127.5, 126.73, 126.70, 126.5,
125.4, 125.0, 123.2, 119.88, 119.80, 76.4, 36.8. HRMS calcd for
(C20H16NaO): 295.1093 (M + Na)+, found 295.1089 (M + Na)+.
monochromated MoKα radiation source at 200ꢀK using
the θ−2θ scan mode. An empirical absorption correction by multi
scans was applied and all of the non-hydrogen atoms were refined
with anisotropic displacement factors. The hydrogen atoms were
placed in ideal positions and fixed with relative isotropic
displacement parameters. The solvent molecules which could not
identify or modelled were found and eventually squeezed using
PLATON.[17] The corresponding loop of the residual electron-
voids (from PLATON) was appended in the corresponding cif
file. The single crystals for X-ray analysis were grown by slow
evaporation of compound 2 or 2.PO in n-hexane/chloroform
solution over a period of 4-5 days. CCDC No. 1900760 (for
compound 2) and 1900761 (2.PO) contains the supplementary
crystallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif
(9H-fluoren-2-yl)(p-tolyl)methanol (7): Similar procedure
mentioned for compound 6 was used to synthesize compound 7.
yield 99.3% ( 2.0 g); 1H NMR (500 MHz, CDCl3) δ 7.77 (d, J =
7.5 Hz, 1H), 7.74 (d, J = 7.9 Hz, 1H), 7.57 (s, 1H), 7.53 (d, J =
7.4 Hz, 1H), 7.43 – 7.34 (m, 2H), 7.33 – 7.27 (m, 3H), 7.17 (d, J
= 7.9 Hz, 2H), 5.90 (s, 1H), 3.87 (s, 2H), 2.33 (d, J = 14.2 Hz,
Computational details: All the calculations were performed
using of the Gaussian 09 program package33 The density
functional theory (DFT)34 method, hybrid functional B3LYP with
ACS Paragon Plus Environment

Page 7 of 11
The Journal of Organic Chemistry
1
2
3
3H), 2.23 (br, 1H); 13C{1H} NMR (126 MHz, CDCl3) δ 143.5,
purified by column chromatography using silica gel (60-
120mesh) in 10% petroleum ether/ethyl acetate to afford 10 in
51.7% Yield (650 mg); 1H NMR (500 MHz, CDCl3) δ 7.73 (s,
2H), 7.66 (dd, J = 7.4, 3.5 Hz, 1H), 7.62 – 7.55 (m, 1H), 7.50 (d,
J = 15.5 Hz, 1H), 7.39 – 7.27 (m, 3H), 7.23 – 7.13 (m, 4H), 7.12
– 6.96 (m, 2H), 6.96 – 6.87 (m, 1H), 6.87 – 6.69 (m, 2H), 6.63 –
6.37 (m, 2H), 6.33 – 5.94 (m, 3H), 5.93 – 5.78 (m, 1H), 5.45 (t, J
= 6.5 Hz, 1H), 5.00 (ddd, J = 21.8, 11.9, 6.1 Hz, 1H), 4.59 (dt, J
= 20.5, 10.1 Hz, 1H); 13C{1H} NMR (126 MHz, CDCl3) δ 144.8,
144.2, 143.1, 141.8, 141.7, 141.3, 139.9, 133.6, 128.8, 128.7,
128.4, 128.37, 128.30, 128.2, 127.5, 126.59, 126.55, 126.3,
126.2, 126.1, 125.9, 125.8, 125.7, 125.6, 125.1, 124.8, 124.09,
124.06, 119.7, 119.6, 117.0, 116.5, 116.4, 108.4, 108.2, 108.1,
108.09, 108.01, 107.7, 107.6, 107.2, 107.1, 106.8, 53.1, 50.5,
43.4; HRMS calcd for (C33H26KN2S): 521.1448 (M + K)+, found
521.1443 (M + K)+.
4
5
6
7
8
9
143.3, 142.6, 141.3, 141.1, 137.2, 129.1, 126.7, 126.6, 126.4,
125.3, 124.9, 123.0, 119.8, 119.7, 76.2, 36.8, 21.1; HRMS calcd
for (C21H18NaO): 309.1250 (M + Na)+, found 309.1248 (M +
Na)+.
(2-(hydroxy(phenyl)methyl)-9H-fluoren-9-yl)(thiophen-2-
yl)methanol (8): A sample of 6 (2.0 g, 7.37 mmol) in dry THF
(30 mL) were charged in a two necked round bottomed flask
equipped with nitrogen bubbler and rubber septum followed by
careful addition of n-BuLi (9.6 mL of 1.6 M solution in hexane,
15.4 mmol) at 0 ºC. The reaction mixture was stirred for 15
minute then ice cold dry THF solution of 2-thiophene
carboxaldehyde (0.82 ml, 8.85 mmol) was added to the above
mixture and allowed to stir for 3 h at room temperature. The
reaction mixture was quenched with saturated solution of NH4Cl
in water and extracted with diethyl ether. The combined organic
layers were washed with water and dried over Na2SO4 and the
solvent was removed under vacuum to afford a yellow oil which
was further purified by silica gel column chromatography with
petroleum ether/ethyl acetate (70/30) to afford the desired pure
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
2-((2-((1H-pyrrol-2-yl)(p-tolyl)methyl)-9H-fluoren-9
yl)(thiophen-2-yl)methyl)-1H-pyrrole (11): Similar procedure
mentioned for compound 10 was used to synthesize compound
11. yield 48.1% (600 mg); 1H NMR (500 MHz, CDCl3) δ 7.72 (s,
2H), 7.67 – 7.60 (m, 1H), 7.56 (td, J = 8.0, 5.5 Hz, 1H), 7.46 (t, J
= 10.3 Hz, 1H), 7.32 (td, J = 7.5, 4.4 Hz, 1H), 7.22 – 6.95 (m,
7H), 6.95 – 6.84 (m, 1H), 6.83 – 6.65 (m, 2H), 6.64 – 6.52 (m,
1H), 6.52 – 6.36 (m, 1H), 6.23 – 6.09 (m, 2H), 6.08 – 5.90 (m,
1H), 5.85 – 5.75 (m, 1H), 5.50 – 5.35 (m, 1H), 5.10 – 4.93 (m,
1H), 4.69 – 4.51 (m, 1H), 2.36 (d, J = 3.6 Hz, 3H); 13C{1H} NMR
(126 MHz, CDCl3) δ 144.6, 142.0, 139.9, 129.1, 128.6, 128.3,
127.57, 126.59, 126.4, 126.0, 125.8, 125.4, 124.8, 124.1, 119.6,
116.8, 116.5, 116.4, 108.5, 108.2, 108.0, 107.6, 107.3, 106.8,
53.1, 50.2, 43.4, 21.0; HRMS calcd for (C34H28KN2S): 535.1605
(M + K)+, found 535.1606 (M + K)+.
1
compound 8 as a white solid in 38.9% Yield (1.1 g); H NMR
(500 MHz, CDCl3) δ 7.67 (d, J = 7.5 Hz, 1H), 7.66 – 7.62 (m,
1H), 7.44 (dd, J = 10.4, 1.9 Hz, 1H), 7.40 – 7.31 (m, 6H), 7.30 –
7.23 (m, 2H), 7.23 – 7.19 (m, 1H), 7.19 – 7.14 (m, 1H), 6.96 –
6.77 (m, 1H), 6.72 (td, J = 4.1, 2.4 Hz, 1H), 5.96 – 5.71 (m, 1H),
5.39 – 5.19 (m, 1H), 4.37 (dd, J = 9.8, 4.6 Hz, 1H), 2.35 (br, Hz,
2H); 13C{1H} NMR (101 MHz, CDCl3) δ 145.6, 145.5, 143.9,
143.49, 143.40, 143.2, 142.6, 141.6, 141.2, 128.4, 127.7, 127.5,
126.8, 126.5, 126.3, 125.9, 125.8, 124.8, 124.29, 124.22, 124.0,
119.8, 119.7, 76.4, 72.9, 72.8, 54.9, 54.8; HRMS calcd for
(C25H20KO2S): 423.0816 (M + K)+, found 423.0817 (M + K)+.
(2-(hydroxy(p-tolyl)methyl)-9H-fluoren-9-yl)(thiophen-2-
yl)methanol (9): Similar procedure mentioned for compound 8
was used to synthesize compound 9. yield 35.9% (1.0 g); 1H
NMR (500 MHz, CDCl3) δ 7.66 (t, J = 7.1 Hz, 1H), 7.62 (dd, J =
7.8, 3.8 Hz, 1H), 7.41 – 7.29 (m, 3H), 7.29 – 7.18 (m, 3H), 7.18
– 7.10 (m, 3H), 7.05 – 6.93 (m, 1H), 6.91 – 6.78 (m, 1H), 6.76 –
6.62 (m, 1H), 5.86 – 5.68 (m, 1H), 5.36 – 5.06 (m, 1H), 4.43 –
4.26 (m, 1H), 2.90 – 2.51 (br, 2H), 2.32 (d, J = 16.2 Hz, 3H);
13C{1H} NMR (126 MHz, CDCl3) δ 145.7, 145.6, 145.5, 143.9,
143.6, 143.4, 143.3, 143.25, 143.20, 143.1, 142.8, 142.6, 141.5,
141.4, 141.2, 141.0, 140.99, 140.91, 137.09, 137.01, 129.08,
129.05, 127.68, 127.63, 126.8, 126.7, 126.6, 126.5, 126.4, 126.3,
126.27, 126.23, 126.20, 126.17, 126.13, 125.7, 125.5, 125.4,
124.88, 124.86, 124.79, 124.71, 124.6, 124.2, 124.0, 123.8,
119.7, 119.6, 119.5, 76.1, 72.7, 72.68, 72.64, 59.8, 54.8, 54.8,
54.7, 21.0; HRMS calcd for (C26H22NaO2S): 421.1233 (M + Na)+,
found 421.1234 (M + Na)+.
10-Hydroxy-5-pentafluorophenyl-10-phenyl-17-thienyl-
meso-fused-carbatriphyrin (2): A sample of 10 (60 mg, 0.12
mmol) and pentafluorobenzaldehyde (15 mg, 0.12 mmol) were
dissolve in 200 ml CH2Cl2 under inert atmosphere and stirred for
10 min. BF3·OEt2 (5 l) was added and allowed to stir for 1 h.
Then 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (54.4 mg, 0.24
mmol) was added to the reaction mixture and further stirred for 1
h in open air. The crude product passed through basic alumina
and further purified by silica column chromatography with 50%
petroleum ether/CH2Cl2 to afford the desired pure compound 2 as
a blue coloured solid in 31.0% yield (26 mg). Similar procedure
was used for the synthesis of macrocycles 3; 1H NMR (500 MHz,
CDCl3) δ 14.67 (d, J = 18.8 Hz, 1H), 8.46 (d, J = 7.5 Hz, 1H),
7.95 (d, J = 7.6 Hz, 1H), 7.62 – 7.53 (m, 3H), 7.42 (d, J = 6.6 Hz,
2H), 7.38 – 7.28 (m, 3H), 7.25 – 7.18 (m, 1H), 7.15 (t, J = 7.4 Hz,
1H), 7.03 (s, 1H), 6.89 (t, J = 5.3 Hz, 1H), 6.85 (d, J = 6.5 Hz,
1H), 6.74 (d, J = 19.2 Hz, 1H), 6.25 (s, 1H), 6.18 (s, 1H), 5.82 –
5.62 (m, 1H), 2.99 (s, 1H); 13C{1H} NMR (126 MHz, CDCl3) δ
146.4, 143.6, 140.8, 139.0, 133.2, 130.1, 128.6, 128.2, 128.0,
127.8, 127.6, 127.5, 127.3, 127.1, 127.0, 126.2, 125.1, 124.8,
124.6, 124.3, 123.7, 120.6, 120.4, 119.9, 119.7, 119.4, 117.3,
79.9; 19F NMR (471 MHz, CDCl3) δ -137.11 (dd, J = 56.3, 22.0
Hz), -138.17 (dd, J = 39.6, 22.7 Hz), -151.54 (t, J = 20.9 Hz), -
160.30 – -160.69 (m); UV-Vis (toluene, λmax/nm, (log ε)]; 344
(3.8), 367 (3.8), 624 (3.7); HRMS calcd for (C40H22F5N2OS):
673.1368 (M + H)+, found 673.1363 (M + H)+.
2-((9-((1H-pyrrol-2-yl)(thiophen-2-yl)methyl)-9H-fluoren-2-
yl)(phenyl)methyl)-1H-pyrrole (10): Compound 8 (1.0 g, 2.60
mmol) and pyrrole (9.0 mL) in 1,2-dichloroethane (40 mL) was
kept in an inert atmosphere for 10 min after which 1.0 mL (7.80
mmol) of BF3·OEt2 solution was added and the resulting mixture
was stirred under reflux for 8 h. The solution was cooled to room
temperature and quenched by addition of triethylamine (2.0 mL).
The compound was extracted with CH2Cl2, dried over Na2SO4
and concentrated by rotary evaporator. The crude mixture was
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 8 of 11
1
2
3
4
5
6
7
8
9
10-Hydroxy-5-pentafluorophenyl-17-thienyl-10-tolyl-meso-
fused-carbatriphyrin (3): Yield 30.1% (25 mg); 1H NMR (500
MHz, CDCl3) δ 14.64 (d, J = 18.7 Hz, 1H), 8.43 (d, J = 10.1 Hz,
1H), 7.95 (d, J = 7.5 Hz, 1H), 7.63 – 7.51 (m, 3H), 7.30 (d, J =
8.2 Hz, 2H), 7.22 (d, J = 11.3 Hz, 2H), 7.14 (dd, J = 16.8, 7.8 Hz,
3H), 7.03 (s, 1H), 6.89 (d, J = 4.2 Hz, 1H), 6.85 (d, J = 6.4 Hz,
1H), 6.78 (s, 1H), 6.24 (s, 1H), 5.73 (dd, J = 43.5, 7.9 Hz, 1H),
2.92 (s, 1H), 2.31 (s, 3H). 13C{1H} NMR (101 MHz, CDCl3) δ
146.5, 140.8, 139.0, 138.1, 133.1, 129.2, 127.0, 126.2, 124.8,
124.2, 123.8, 119.4, 117.2, 79.9, 21.0; 19F NMR (471 MHz,
CDCl3) δ -137.10 (dd, J = 57.1, 21.9 Hz), -138.17 (dd, J = 40.1,
23.4 Hz), -151.54 (t, J = 20.9 Hz), -160.18 – -160.72 (m); UV-
Vis (toluene, λmax/nm, (log ε)]; 344 (3.8), 367 (3.8), 626 (3.7);
HRMS calcd for (C41H24F5N2OS): 687.1524 (M + H)+, found
687.1524 (M + H)+.
UGC for the doctoral fellowship and KGT is thankful to IIT
Bombay for post -doctoral fellowship.
REFERENCES
(1)
Xue, Z. L.; Shen, Z.; Mack, J.; Kuzuhara, D.; Yamada,
H.; Okujima, T.; Ono, N.; You, X. Z.; Kobayashi, N. A
Facile One-Pot Synthesis of Meso-Aryl-Substituted
[14]Triphyrin(2.1.1). J. Am. Chem. Soc. 2008, 130 (49),
16478–16479.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(2)
(3)
Kuzuhara, D.; Xue, Z.; Mori, S.; Okujima, T.; Uno, H.;
Aratani, N.; Yamada, H. Synthesis and Properties of
Boron Complexes of [14]Triphyrins(2.1.1). Chem.
Commun. 2013, 49 (79), 8955–8957.
PO complex of 10-Hydroxy-5-pentafluorophenyl-10-phenyl-
17-thienyl-meso-fused-cabatriphyrin (2.PO): Compound 2 (20
mg, 0.029 mmol) and TEA 380 l (2.9 mmol) in toluene (5 mL)
was kept in an inert atmosphere for 10 min after which 507 L
(5.8 mmol) of PCl3 was added and the resulting mixture was
stirred under reflux for 1 h. The solution was cooled to room
temperature and the solvent was removed under vacuum. The
crude compound was purified by column chromatography using
silica gel (60-120mesh) in 20% petroleum ether/EtOAc to afford
the desired pure compound 2.PO as a red coloured solid in 48.0%
yield (10 mg); 1H NMR (500 MHz, CDCl3) δ 8.27 (d, J = 7.6 Hz,
1H), 8.23 (d, J = 8.4 Hz, 1H), 7.89 (d, J = 7.2 Hz, 1H), 7.73 – 7.65
(m, 1H), 7.65 – 7.48 (m, 6H), 7.43 – 7.34 (m, 1H), 7.28 (s, 1H),
7.12 (s, 1H), 7.01 (s, 1H), 6.84 (s, 1H), 6.70 (s, 1H), 6.62 (d, J =
8.2 Hz, 1H), 6.53 (d, J = 9.1 Hz, 1H); 13C{1H} NMR (126 MHz,
CDCl3) δ 141.6, 141.3, 140.0, 137.8, 136.2, 135.7, 135.2, 130.7,
130.06, 130.01, 129.4, 129.2, 128.6, 127.7, 127.6, 127.3, 127.1,
127.0, 125.7, 125.5, 125.0, 124.9, 124.5, 123.47, 123.43, 123.0,
118.9, 113.4, 95.6; 31P NMR (202 MHz, CDCl3) δ -11.61, -11.74;
19F NMR (471 MHz, CDCl3) δ -135.91 (t, J = 27.1 Hz), -137.60
(t, J = 22.9 Hz), -151.92 (t, J = 21.0 Hz), -159.71 – -160.22 (m),
-160.27 – -160.85 (m); UV-Vis (toluene, λmax/nm, (log ε)]; 345
(3.9), 415 (4.0), 487 (3.3), 524 (3.3), 565 (3.1) 652 (3.0), 706 (2.9)
(3.7); HRMS calcd for (C40H19F5N2OPS): 701.0870 (M + H)+,
found 701.0870 (M + H)+
Kuzuhara, D.; Kawatsu, S.; Furukawa, W.; Hayashi,
H.; Aratani, N.; Yamada, H. Synthesis of
[14]Oxatriphyrins(2.1.1) and Their Transformation into
Ethane-Bridged Oxatripyrrins by Boron Complexation.
Eur. J. Org. Chem. 2018, 2018 (18), 2122–2129.
(4)
(5)
Inokuma, Y.; Osuka, A. Subporphyrins: Emerging
Contracted Porphyrins with Aromatic 14π-Electronic
Systems and Bowl-Shaped Structures: Rational and
Unexpected Synthetic Routes. Dalton Trans. 2008, 0
(19), 2517–2526.
Shimizu, D.; Oh, J.; Furukawa, K.; Kim, D.; Osuka, A.
Meso-Hydroxysubporphyrins: A Cyclic Trimeric
Assembly and a Stable Meso-Oxy Radical. Angew.
Chem., Int. Ed. 2015, 54 (22), 6613–6617.
(6)
(7)
(8)
Takeuchi, Y.; Matsuda, A.; Kobayashi, N. Synthesis
and Characterization of Meso-Triarylsubporphyrins. J.
Am. Chem. Soc. 2007, 129 (26), 8271–8281.
Tsurumaki, E.; Hayashi, S. Y.; Tham, F. S.; Reed, C.
A.; Osuka, A. Planar Subporphyrin Borenium Cations.
J. Am. Chem. Soc. 2011, 133 (31), 11956–11959.
Shimizu, S. Recent Advances in Subporphyrins and
Triphyrin Analogues: Contracted Porphyrins
Comprising Three Pyrrole Rings. Chem. Rev. 2017, 117
(4), 2730–2784.
(9)
Kitano, M.; Hayashi, S. Y.; Tanaka, T.; Yorimitsu, H.;
Aratani, N.; Osuka, A. Effective Meso Fabrications of
Subporphyrins. Angew. Chem., Int. Ed. 2012, 51 (23),
5593–5597.
SUPPORTING INFORMATION
1
Characterization data (HRMS, H, 13C{1H}, 31P, 19F, 2D NMR,
electronic absorption spectra, electrochemical and DFT
computational data) for all of the reported compounds.
(10)
Inokuma, Y.; Zin, S. Y.; Kim, D.; Osuka, A. Meso-
Aryl-Substituted Subporphyrins: Synthesis, Structures,
and Large Substituent Effects on Their Electronic
Properties. J. Am. Chem. Soc. 2007, 129 (15), 4747–
4761.
X-ray crystallographic data for compounds 2 and 2.PO.
AUTHOR INFORMATION
Corresponding author
(11)
(12)
Tsurumaki, E.; Sung, J.; Kim, D.; Osuka, A.
Subporphyrinato Boron(III) Hydrides. J. Am. Chem.
Soc. 2015, 137 (3), 1056–1059.
*E-mail: ravikanth@chem.iitb.ac.in
ACKNOWLEDGEMENTS
Hayashi, S. Y.; Tsurumaki, E.; Inokuma, Y.; Kim, P.;
Sung, Y. M.; Kim, D.; Osuka, A. Synthesis and
Properties of Boron(III)-Coordinated
MR thanks Science & Engineering Research Board, Govt. of
India (EMR/2015/002196) for funding the project and AK thanks
ACS Paragon Plus Environment

Page 9 of 11
The Journal of Organic Chemistry
1
2
3
4
5
6
7
Subbacteriochlorins. J. Am. Chem. Soc. 2011, 133 (12),
4254–4256.
L. Phosphorus Complexes of N-Fused Porphyrin and
Its Reduced Derivatives: New Isomers of Porphyrin
Stabilized via Coordination. Inorg. Chem. 2008, 47
(14), 6364–6374.
(13)
Sarma, T.; Panda, P. K. Annulated Isomeric, Expanded,
and Contracted Porphyrins. Chem. Rev. 2017, 117 (4),
2785–2838.
(27)
Pacholska-Dudziak, E.; Ulatowski, F.; Ciunik, Z.;
Latos-Gražyński, L. N-Fusion Approach in
Construction of Contracted Carbaporphyrinoids:
Formation of N-Fued Telluraporphyrin. Chem. Eur. J.
2009, 15 (41), 10924–10929.
8
9
(14)
(15)
Ishii, K.; Kobayashi, N. The Porphyrin Handbook, Vol.
6; Academic Press, 2003.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Vogel, E. Porphyrinoid Macrocycles: A Cornucopia of
Novel Chromophores. Pure Appl. Chem. 2007, 68 (7),
1355–1360.
(28)
(29)
Anju, K. S.; Ramakrishnan, S.; Srinivasan, A. Meso-
Aryl Triphyrin(2.1.1). Org. Lett. 2011, 13 (9), 2498–
2501.
(16)
(17)
Xue, S.; Kuzuhara, D.; Aratani, N.; Yamada, H.
Synthesis and Characterization of an Iridium Triphyrin
Complex. Inorg. Chem. 2016, 55 (20), 10106–10109.
Krygowski, T. M.; Anulewicz, R.; Kruszewski, J.
Crystallographic Studies and Physicochemical
Properties of Π‐electron Compounds. III. Stabilization
Energy and the Kekulé Structure Contributions Derived
from Experimental Bond Lengths. Acta Crystallogr.
Sect. B 1983, 39 (6), 732–739.
Xue, Z. L.; MacK, J.; Lu, H.; Zhang, L.; You, X. Z.;
Kuzuhara, D.; Stillman, M.; Yamada, H.; Yamauchi,
S.; Kobayashi, N.; et al. The Synthesis and Properties
of Free-Base [14]Triphyrin(2.1.1) Compounds and the
Formation of Subporphyrinoid Metal Complexes.
Chem. Eur. J. 2011, 17 (16), 4396–4407.
(30)
(31)
Sheldrick, G. M.; A short history of SHELX. Acta
Crystallogr. 2008, A64, 112-122.
(18)
(19)
Xue, Z.; Kuzuhara, D.; Ikeda, S.; Sakakibara, Y.;
Ohkubo, K.; Aratani, N.; Okujima, T.; Uno, H.;
Fukuzumi, S.; Yamada, H. Η5-
Cyclopentadienyliron(II)-[14]Triphyrin(2.1.1)
Sandwich Compounds: Synthesis, Characterization, and
Stable Redox Interconversion. Angew. Chem., Int. Ed.
2013, 52 (28), 7306–7309.
Altomare, A.; Cascarano, G.; Giacovazzo, C.;
Guagliardi, A.; Burla, M. C.; Polidori, G.; Camalli, M.
SIR 92 – a Program for Automatic Solution of Crystal
Structures by Direct Methods. J. Appl. Crystallogr.
1994, 27 (3), 435–435.
(32)
(33)
Farrugia, L. J. WinGX Suite for Small-Molecule
Single-Crystal Crystallography. J. Appl. Crystallogr.
1999, 32 (4), 837–838.
Kuzuhara, D.; Yamada, H.; Xue, Z.; Okujima, T.; Mori,
S.; Shen, Z.; Uno, H. New Synthesis of Meso-Free-
[14]Triphyrin(2.1.1) by McMurry Coupling and Its
Derivatization to Mn(i) and Re(i) Complexes. Chem.
Commun. 2011, 47 (2), 722–724.
Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria,
G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.;
Barone, V.; Mennucci, B.; Petersson, G. A.; et al.
Gaussian 09, Revision C.01. Gaussian 09, Revision
B.01, Gaussian, Inc., Wallingford CT 2009.
(20)
(21)
Panda, K. N.; Thorat, K. G.; Ravikanth, M. Synthesis
of Meso-Tetraaryl Triphyrins(2.1.1). J. Org. Chem.
2018, 83 (20), 12945–12950.
(34)
(35)
(36)
Treutler, O.; Ahlrichs, R. Efficient Molecular
Numerical Integration Schemes. J. Chem. Phys. 1995,
102 (1), 346–354.
Kuzuhara, D.; Sakakibara, Y.; Mori, S.; Okujima, T.;
Uno, H.; Yamada, H. Thiatriphyrin(2.1.1): A Core-
Modified Contracted Porphyrin. Angew. Chem., Int. Ed.
2013, 52 (12), 3360–3363.
Becke, A. D. A New Mixing of Hartree-Fock and Local
Density-Functional Theories. J. Chem. Phys. 1993, 98
(2), 1372–1377.
(22)
Pawlicki, M.; Garbicz, M.; Szterenberg, L.; Latos-
Grazyński, L. Oxatriphyrins(2.1.1) Incorporating an
Ortho-Phenylene Motif. Angew. Chem., Int. Ed. 2015,
54 (6), 1906–1909.
Bauernschmitt, R.; Ahlrichs, R. Treatment of Electronic
Excitations within the Adiabatic Approximation of
Time Dependent Density Functional Theory. Chem.
Phys. Lett. 1996, 256 (4–5), 454–464.
(23)
(24)
(25)
Kumar, A.; Rajeswara Rao, M.; Lee, W. Z.; Ravikanth,
M. Hybrid Macrocycles of Subporphyrins and
Triphyrins. Org. Lett. 2017, 19 (21), 5924–5927.
(37)
(38)
Hehre, W. J. Ab Initio Molecular Orbital Theory. Acc.
Chem. Res. 1976, 9 (11), 399–406.
Kumar, A.; Thorat, K. G.; Ravikanth, M. Benzofuran-
/Benzothiophene-Incorporated NIR-Absorbing
Triphyrins(2.1.1). Org. Lett. 2018, 20 (16), 4871–4874.
Thorat, K. G.; Kamble, P. S.; Ray, A. K.; Sekar, N.
Novel Pyrromethene Dyes with N-Ethyl Carbazole at
Meso Position: Comprehensive Photophysical, Lasing,
Photostability and TD-DFT Study. Phys. Chem. Chem.
Phys. 2015, 17, 17221–17236.
Berlicka, A.; Latos-Grazyński, L.; Lis, T.
Dithiaethyneporphyrin: An Atypical
[18]Triphyrin(4.1.1) Frame for Contracted Porphyrins.
Angew. Chem., Int. Ed. 2005, 44 (33), 5288–5291.
(39)
Cossi, M.; Barone, V.; Cammi, R.; Tomasi, J. Ab Initio
Study of Solvated Molecules: A New Implementation
of the Polarizable Continuum Model. Chem. Phys. Lett.
1996, 255 (4–6), 327–335.
(26)
Młodzianowska, A.; Latos-Grazyński, L.; Szterenberg,
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 10 of 11
1
2
3
4
5
(40)
Tomasi, J.; Mennucci, B.; Cammi, R. Quantum
Mechanical Continuum Solvation Models. Chem. Rev.
2005, 105 (8), 2999–3094.
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
ACS Paragon Plus Environment

Page 11 of 11
The Journal of Organic Chemistry
1
2
3
4
5
6
TOC graphic
7
8
9
Meso-fused Carbatriphyrins(2.1.1)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
HO
Ar
PCl3
Ar
Ar
O
N
O
N
Ar
Ar
Ar
P
P
HN
N
N
N
Ar
Ar
Ar
Non-aromatic
22 
Aromatic
18 
ACS Paragon Plus Environment