Communication
4
5
4
molar absorptivities of 7.3 × 10 (2), 1.9 × 10 (3), and 1.1 × 10
jected to flash column chromatography (SiO ; gradient elution from
2
toluene to 20 % EtOAc/toluene) to give 3 (19 mg, 76 %) as a purple
–
1
–1
(
12)
M
cm , in agreement with the fact that the conjugation
solid. Crystals suitable for X-ray crystallography were grown from
at the SubPc periphery has not been changed and that substit-
1
uents on the oxygen atom are known[1b] to have only minor
CHCl
3
/heptane. R
f
= 0.27 (20 % EtOAc/toluene). M.p. > 230 °C. H
NMR (500 MHz, C D ): δ = 8.77 (dd, J = 5.9, 3.0 Hz, 12 H), 7.39 (dd,
6
6
effects on the characteristic boron SubPc absorption maximum.
J = 5.9, 3.0 Hz, 12 H), 1.44 (t, J = 6.8 Hz, 4 H), 1.13 (t, J = 6.8 Hz, 4
H) ppm. 13C NMR (126 MHz, C D ): δ = 151.65, 131.91, 129.60,
6
6
1
22.29, 74.08, 66.61, 57.76, 22.02 ppm. HR-MS (MALDI+ FT-ICR, di-
Conclusions
+
thranol): calcd. for [C H B N O ] 927.30301; found 927.30235
5
6 33 2 12 2
+
[M + H] . C H B N O (926.6): calcd. C 72.59, H 3.48, N 18.14;
56 32 2 12 2
We have prepared a new SubPc derivative with an acetylenic
substituent at the axial position and proven that this compound
is a convenient building block for acetylenic scaffolding using
metal-catalyzed coupling reactions. In particular, this has al-
lowed us to prepare dimeric structures and subphthalocyanine–
buckminsterfullerene dyads. We also managed to functionalize
TEEs with SubPc units; such compounds may act as precursors
found C 72.65, H 3.56, N 17.92. UV/Vis (CHCl ): λ
[nm] (log ε
3
max
–1
–1
[
M
cm ]) = 563 (5.3), 545sh, 516sh, 304 (5.0), 270 (4.9), 253sh.
Compound 12: A degassed solution of Et N/toluene (1:3, 3 mL) was
added to an argon-purged flask containing 11 (22 mg, 0.026 mmol),
2
3
(25 mg, 0.054 mmol, 2.05 equiv.), AsPh3 (16 mg, 0.053 mmol,
200 mol-%), Pd dba3 (6.1 mg, 0.007 mmol, 25 mol-%), and CuI
2
(
1.2 mg, 0.006 mmol, 24 mol-%), and the resulting suspension was
[
12]
for electron-accepting expanded radialenes
coated with stirred for 3 h. The reaction mixture was diluted with EtOAc (3 mL)
light-harvesting SubPcs upon oxidative cyclizations, which will and filtered through a short plug of SiO , eluting with additional
2
be the subject of future work. The most successful use of the EtOAc (15 mL). The filtrate was concentrated in vacuo, and the resi-
due was taken up in a small volume of toluene and subjected to
new acetylenic SubPc building block in terms of reaction yield
was, however, in the CuAAC reaction, at least when the sub-
strates can tolerate elevated temperatures. In the future it could
also be interesting to use the axial alkyne functionality in com-
bination with peripherally substituted SubPc derivatives.
flash column chromatography (SiO ; gradient elution from toluene
2
to 10 % EtOAc/toluene) to give 12 (30 mg, 76 %) as a red solid. R =
f
1
0
.31 (10 % EtOAc/toluene). M.p. > 230 °C. H NMR (500 MHz, CDCl ):
3
δ = 8.83 (dd, J = 5.8, 3.0 Hz, 12 H), 7.88 (dd, J = 5.8, 3.0 Hz, 12 H),
7
4
.35 (d, J = 8.3 Hz, 4 H), 7.11 (d, J = 8.3 Hz, 4 H), 1.68 (t, J = 6.5 Hz,
H), 1.62 (t, J = 6.5 Hz, 4 H), 1.13–1.09 (m, 42 H) ppm. C NMR
1
3
(
1
8
126 MHz, CDCl ): δ = 151.66, 131.64, 131.50, 131.11, 129.86, 124.29,
22.23, 121.67, 117.53, 117.40, 104.17, 102.54, 98.49, 89.17, 88.46,
3
Experimental Section
0.91, 57.98, 22.09, 18.80, 11.44 ppm. HR-MS (MALDI+ FT-ICR, di-
General: Representative protocols are provided below. The Sup-
porting Information contains all synthetic protocols and NMR spec-
tra.
+
thranol): calcd. for [C H B N O Si ]
1
5
1513.64811; found
96 83 2 12 2 2
+
513.64661 [M + H] . C H B N O Si (1513.6): calcd. C 76.18, H
96 82 2 12 2 2
.46, N 11.11; found C 76.02, H 5.56, N 10.99. UV/Vis (CHCl ): λ
3 max
–
1
–1
Compound 2: Dry toluene (4 mL) was added to a flask with 1
(
and the resulting mixture was stirred under argon. After 2 h, con-
sumption of 1 was determined to be complete by TLC. Hünig's base
[nm] (log ε [
M
cm ]) = 563 (5.4), 545sh, 518sh, 409sh, 390 (4.8),
100 mg, 0.232 mmol) and AgOTf (75 mg, 0.29 mmol, 1.25 equiv.), 378 (4.8), 305 (5.2), 269 (5.1), 255sh.
Compound 14. Method A: To a stirred solution of 2 (22 mg,
.047 mmol), 13a (90 mg, 0.083 mmol, 1.75 equiv.), PdCl (PPh )
0
(
3
2
3 2
(51 μL, 0.29 mmol, 1.25 equiv.) was added followed by 3-butyn-1-
6.5 mg, 0.0093 mmol, 20 mol-%), and CuI (2.7 mg, 0.014 mmol,
ol (105 μL, 1.39 mmol, 6 equiv.) at which point a significant color
change from purple to red was noticed. Stirring was continued for
0 mol-%) in toluene (10 mL) was added Et N (0.6 mL, 4.30 mmol).
3
After stirring in an open flask for 3 h, the reaction mixture was
diluted with CS (10 mL) and passed through a short plug of SiO
followed by additional 50 % EtOAc/CS2 (40 mL). The filtrate was
concentrated under reduced pressure, and the crude residue was
subjected to flash column chromatography (SiO ; gradient elution
from CS2 to 5 % EtOAc/toluene) to afford 14 (11 mg, 16 %) as a
dark purple solid. Method B: A degassed solution of Et N/toluene
(
0
0
2
0 h, after which the reaction mixture was passed through a short
2
2
plug of SiO , eluting with additional EtOAc (100 mL). The filtrate
2
was concentrated under reduced pressure, and the solid residue
was redissolved in a small volume of CH Cl and subjected to flash
2
2
2
column chromatography (SiO ; gradient elution from 5 to 10 %
2
EtOAc/toluene) to afford 2 (46 mg, 43 %) as a red solid. Crystals
suitable for X-ray crystallography were grown from CH Cl /heptane.
3
2
2
1:4) (3 mL) was added to an argon-purged flask with 13b (36 mg,
1
R = 0.38 (10 % EtOAc/toluene). M.p. > 230 °C. H NMR (500 MHz,
f
.030 mmol), 2 (17 mg, 0.036 mmol, 1.2 equiv.), Pd dba (6.8 mg,
2 3
C D ): δ = 8.76 (dd, J = 5.8, 3.0 Hz, 6 H), 7.38 (dd, J = 5.8, 3.0 Hz, 6
6
6
.0074 mmol, 25 mol-%), and CuI (1.1 mg, 0.0060 mmol, 20 mol-%).
H), 1.55 (t, J = 6.9 Hz, 2 H), 1.31 (t, J = 2.7 Hz, 1 H), 1.21 (td, J = 6.9,
The resulting mixture was stirred for 21 h, concentrated in vacuo,
redissolved in a small volume of CS and subjected to flash column
chromatography (SiO ; 3 % EtOAc/toluene) to afford 14 (16 mg,
3
2
1
.7 Hz, 2 H) ppm. 13C NMR (126 MHz, C D ): δ = 151.65, 131.89,
29.64, 122.25, 81.34, 69.09, 58.06, 21.28 ppm. HR-MS (MALDI+ FT-
6 6
2
+
2
ICR, dithranol): calcd. for [C H BN O] 465.16346; found 465.16312
2
8
18
6
5 %) as a dark purple solid. R = 0.24 (5 % EtOAc/toluene). M.p.
+
f
[
M + H] . C H BN O (464.3): calcd. C 72.43, H 3.69, N 18.10;
28 17 6
1
>
230 °C. H NMR (500 MHz, CDCl ): δ = 8.79 (dd, J = 5.7, 2.7 Hz, 6
3
found C 72.55, H 3.61, N 17.97. UV/Vis (CHCl ): λ
[nm] (log ε
3
max
H), 7.82 (br. s, 2 H), 7.76 (dd, J = 5.7, 2.7 Hz, 6 H), 7.52 (d, J = 8.1 Hz,
H), 7.03 (d, J = 8.1 Hz, 2 H), 5.04 (s, 1 H), 4.71 (d, J = 9.6 Hz, 1 H),
–1
–1
[
M
cm ]) = 563 (4.9), 545sh, 518sh, 304 (4.5), 270 (4.5), 254sh.
4
Compound 3: To a stirred solution of 2 (25 mg, 0.054 mmol),
4.43 (d, J = 13.2 Hz, 1 H), 4.08–3.98 (m, 3 H), 3.62 (d, J = 13.2 Hz, 1
H), 1.83 (p, J = 7.1 Hz, 2 H), 1.64 (t, J = 6.6 Hz, 2 H), 1.55 (t, J =
6.6 Hz, 2 H), 1.49 (p, J = 7.1 Hz, 2 H), 1.40–1.28 (m, 8 H), 0.89 (t, J =
PdCl (PPh ) (7.8 mg, 0.011 mmol, 20 mol-%), and CuI (3.0 mg,
2
3 2
0
.016 mmol, 30 mol-%) in THF was added Et N (0.6 mL, 4.30 mmol).
3
The reaction mixture was stirred open to air for 3 h and then filtered
6.5 Hz, 3 H) ppm. 13C NMR (126 MHz, CDCl ): δ = 158.91, 155.92,
3
through a short plug of SiO , rinsing with additional 50 % EtOAc/
153.63, 152.77, 152.71, 151.67, 146.48, 146.40, 146.25, 145.97,
2
toluene (100 mL). The filtrate was concentrated under reduced pres- 145.62, 145.54, 145.53, 145.51, 145.46, 145.35, 145.29, 145.12,
sure, the residue dissolved in a small volume of CH Cl and sub- 145.08, 145.05, 145.00, 144.87, 144.86, 144.76, 144.51, 144.43,
2
2
Eur. J. Org. Chem. 2016, 17–21
www.eurjoc.org
20
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim