A R T I C L E S
Krumova and Cosa
8
-Hydroxymethyl-2,6-dichloro-1,3,5,7-tetramethyl Pyrro-
8-Formyl-2-chloro-1,3,5,7-tetramethyl Pyrromethene Fluo-
roborate, 13. Reaction of 8-hydroxymethyl-2-chloro-1,3,5,7-tet-
ramethyl pyrromethene fluoroborate, 7 (0.1 g, 0.32 mmol), and
Dess-Martin periodinane (0.2 g, 0.48 mmol) took place for 15
methene Fluoroborate, 8. 8-Acetoxymethyl-2,6-dichloro-1,3,5,7-
tetramethyl pyrromethene fluoroborate, 3 (0.22 g, 0.57 mmol), was
stirred for 4 h in the presence of LiOH (0.12 g, 2.9 mmol) according
to procedure 1 described above to give 8 as red-green crystals (0.17
min according to the procedure described above to give 13 as a
1
1
g, 84%). H NMR (500 MHz, CDCl
3
) δ 4.92-4.91 (d, J ) 5.1
purple-green powder (0.08 g, 80%). H NMR (500 MHz, CDCl
3
)
Hz, 2H), 2.55 (s, 6H), 2.50 (s, 6H); 13C NMR (125 MHz, CDCl
δ 153.3, 138.6, 136.1, 130.5, 123.3, 55.9, 22.9, 12.9, 12.6; HRMS
)
δ 10.54 (s, 1H), 6.11, (s, 1H), 2.54, (s, 6H), 2.12 (s, 3H), 2.09 (s,
3
1
3
3
H); C NMR (125 MHz, CDCl
3
) δ 192.6, 160.9, 152.8, 143.2,
-
136.1, 134.7, 129.6, 126.0, 122.6, 122.3, 15.5, 15.0, 12.7, 12.5;
HRMS (ESI) for C H N OBClF (M ) calcd 309.07830, found
14 14 2 2
09.07788; FTIR 642, 818, 1550, 1710 cm .
(
ESI) for C14
FTIR 606, 718, 996, 1052, 1552, 3544 cm
-Hydroxymethyl-2-cyano-1,3,5,7-tetramethyl Pyrromethene
15 2 2 2
H N OBCl F (M ) calcd 345.05498, found 345.05507;
-
-1
.
-1
3
8
8-Formyl-2,6-dichloro-1,3,5,7-tetramethyl Pyrromethene Flu-
Fluoroborate, 9. 8-Acetoxymethyl-2-cyano-1,3,5,7-tetramethyl
pyrromethene fluoroborate, 4 (0.08 g, 0.23 mmol, 1 equiv), was
stirred for 4 h in the presence of HCl according to procedure 2
described above to give 9 as an orange powder with quantitative
yield. H NMR (500 MHz, CDCl
.63 (s, 3H), 2.62 (s, 3H), 2.59 (s, 3H), 2.56 (s, 3H); C NMR
125 MHz, CDCl ) δ 164.0, 154.5, 146.5, 140.4, 139.3, 135.6,
29.5, 125.4, 114.9, 55.7, 16.2, 15.3, 13.9, 13.4; HRMS (ESI) for
oroborate, 14. Reaction of 8-hydroxymethyl-2,6-dichloro-1,3,5,7-
tetramethyl pyrromethene fluoroborate, 8 (0.1 g, 0.29 mmol), and
Dess-Martin periodinane (0.18 g, 0.43 mmol) took place for 30
min according to the procedure described above to give 14 as a
1
3
) δ 6.27 (s, 1H), 4.93 (s, 2H),
1
purple-green powder (0.08 g, 80%). H NMR (500 MHz, CDCl
3
)
13
2
(
1
C
13
δ 10.55 (s, 1H), 2.57 (s, 6H), 2.12 (s, 6H); C NMR (125 MHz,
CDCl ) δ 192.1, 155.5, 136.3, 136.2, 126.9, 123.4, 12.9, 12.8;
HRMS (ESI) for C14
43.03892; FTIR 600, 676, 990, 1182, 1554, 1716 cm
-Formyl-2-cyano-1,3,5,7-tetramethyl Pyrromethene Fluo-
3
3
-
13 2 2 2
H N OBCl F (M ) calcd 343.03933, found
-
15
H
16
N
3
OBF
063, 1190, 1558, 2223, 3537 cm .
-Hydroxymethyl-2,6-dicyano-1,3,5,7-tetramethyl Pyrro-
2
(M ) calcd 302.12817, found 302.12786; FTIR 976,
-1
3
.
-1
1
8
8
roborate, 15. Reaction of 8-hydroxymethyl-2-cyano-1,3,5,7-tet-
ramethyl pyrromethene fluoroborate, 9 (0.1 g, 0.33 mmol), and
Dess-Martin periodinane (0.21 g, 0.5 mmol) took place for 1 h
methene Fluoroborate, 10. 8-Acetoxymethyl-2,6-dicyano-1,3,5,7-
tetramethyl pyrromethene fluoroborate, 5 (0.2 g, 0.54 mmol), was
stirred for 4 h in the presence of LiOH (0.11 g, 2.7 mmol) according
according to the procedure described above to give 15 as a brown-
1
green powder (0.09 g, 91%). H NMR (500 MHz, CDCl
3
) δ 10.56
to procedure 1 described above to give 10 as a red powder (0.15 g,
1
(s, 1H), 6.28 (s, 1H), 2.63 (s, 3H), 2.61 (s, 3H), 2.25 (s, 3H), 2.17
(s, 3H); C NMR (125 MHz, CDCl ) δ 191.6, 166.6, 156.3, 146.4,
40.7, 136.9, 132.4, 125.9, 125.2, 114.3, 103.5, 15.8, 15.6, 14.0,
13.5; HRMS (ESI) for C H N OBF (M ) calcd 300.11143, found
15 14 3 2
300.11236; FTIR 976, 1059, 1316, 1549, 2220, 1714 cm
8
6
1
3%). H NMR (400 MHz, d
6
-acetone) δ 2.85 (s, 2H), 2.78 (s,
-acetone) δ 158.9, 148.5,
46.7, 132.5, 113.1, 54.8, 14.1, 13.0; HRMS (ESI) for
13
H), 2.66 (s, 6H); 13C NMR (75 MHz, d
3
6
1
-
-
16 15 4 2
C H N OBF (M ) calcd 327.1223, found 327.1227; FTIR 1000,
197, 1551, 2223, 3549 cm .
-
1
-1
.
1
8-Formyl-2,6-dicyano-1,3,5,7-tetramethyl Pyrromethene Flu-
General Procedure for the Synthesis of Aldehyde Bodipy
Derivatives (Dess-Martin Oxidation). Dess-Martin periodinane
1.5 equiv) was dissolved in dry dichloromethane. To the suspension
oroborate, 16. Reaction of 8-hydroxymethyl-2,6-dicyano-1,3,5,7-
tetramethyl pyrromethene fluoroborate, 10 (0.1 g, 0.3 mmol), and
Dess-Martin periodinane (0.19 g, 0.45 mmol) took place for 1.5 h
(
was slowly added a solution of meso-acetoxymethyl bodipy dyes
PMOH, 6, 7, 8, 9, and 10 (1 equiv) in dry dichloromethane at 0 °C
under argon. After 10 min, the ice bath was removed and the
reaction mixture was left stirring at room temperature for extended
periods of time as detailed below. The reaction mixture was
extracted with saturated aqueous Na
aqueous NaHCO and brine. The combined organic solutions were
dried over MgSO . The solvent was evaporated, and the residue
according to the procedure described above to give 16 as a purple
1
powder (0.095 g, 97%). H NMR (500 MHz, CDCl
1
3
) δ 10.59 (s,
) δ
90.2, 162.4, 147.8, 140.2, 128.8, 112.8, 107.3, 14.9, 14.2; HRMS
13
H), 2.73 (s, 6H), 2.36 (s, 6H); C NMR (125 MHz, CDCl
3
1
(
-
ESI) for C16
FTIR 995, 1197, 1313, 1545, 1718, 2228 cm
-(N-Butyl)-methylimine-2,6-diethyl-1,3,5,7-tetramethyl Pyr-
13 4 2
H N OBF (M ) calcd 325.10777, found 325.10689;
2
S
2
O
3
followed by saturated
-1
.
3
8
4
romethene Fluoroborate, 20. Butylamine (0.02 g, 0.27 mmol, 1.5
equiv) and Dabco (0.12 g, 1.08 mmol, 6 equiv) were dissolved in
was purified using flash column chromatography with dichlo-
romethane as the eluent.
1
mL of dry toluene under argon. The solution was heated to 90
8
-Formyl-2,6-diethyl-1,3,5,7-tetramethyl Pyrromethene Fluo-
°C. Titanium chloride (0.27 mL of 1 M in dichloromethane, 1.5
equiv) was added dropwise to the heated reaction mixture, followed
by addition of 1 mL of a toluene solution of 8-formyl-2,6-diethyl-
roborate, 11. Reaction of 8-hydroxymethyl-2,6-diethyl-1,3,5,7-
tetramethyl pyrromethene fluoroborate, PMOH (0.1 g, 0.3 mmol),
and Dess-Martin periodinane (0.19 g, 0.45 mmol) took place for
5 min according to the procedure described above to give 11 as
a purple powder (0.073 g, 74%). H NMR (500 MHz, CDCl
1
,3,5,7-tetramethyl pyrromethene fluoroborate, 11 (0.06 g, 0.18
mmol, 1 equiv). After 3 h of reflux the reaction mixture was cooled
to room temperature. The formed precipitate was filtered and
washed with dichloromethane. The solvent was evaporated under
reduced pressure, and the residue was purified using flash column
1
1
3
) δ
1
4
0.61 (s, 1H), 2.51 (s, 6H), 2.39-2.34 (q, J ) 7.6 Hz, J ) 7.5 Hz,
1
3
H), 2.04 (s, 6H), 1.05-1.02 (t, J ) 7.7 Hz, J ) 7.5 Hz, 6H); C
chromatography with hexane/ethyl acetate ) 10/1. A purple powder
NMR (125 MHz, CDCl ) δ 194.1, 156.7, 136.4, 134.8, 133.6, 17.1,
3
1
-
was obtained (0.058 g, 83%); H NMR (500 MHz, CDCl
3
) δ 8.50
1
3
4.6, 12.9, 12.8; HRMS (ESI) for C18
23 2 2
H N OBF (M ) calcd
(
(
(
s, 1H), 3.66-3.70 (dt, 2H), 2.49 (s, 6H), 2.33-2.37 (q, 4H), 2.01
33.19443, found 333.19453; FTIR:, 979, 1183, 1319, 1551, 1711
s, 6H), 1.72-1.77 (quintet, 2H), 1.44-1.51 (sextet, 2H), 1.01-1.04
-
1
cm .
1
3
t, 6H), 0.96-0.99 (t, 3H); C NMR (125 MHz, CDCl
3
) δ 157.1,
8
-Formyl-1,3,5,7-tetramethyl Pyrromethene Fluoroborate,
1
54.8, 136.9, 134.8, 132.8, 129.9, 62.1, 31.9, 30.8, 17.1, 14.7, 13.9,
+
1
2. Reaction of 8-hydroxymethyl-1,3,5,7-tetramethyl pyrromethene
22 32 2 3
13.8, 12.6; HRMS (ESI) for C H BF N (M ) calcd 388.27301
found 388.27342; FTIR 1651, 1538, 1321, 1190, 1043, 961 cm
-
1
fluoroborate, 6 (0.1 g, 0.35 mmol), and Dess-Martin periodinane
0.23 g, 0.53 mmol) took place for 30 min according to the
procedure described above to give 12 as a brown-green powder
(
8-(N-Butyl)-methylimine-2-chloro-1,3,5,7-tetramethyl Pyr-
romethene Fluoroborate, 21. 8-Formyl-2-chloro-1,3,5,7-tetram-
ethyl pyrromethene fluoroborate, 13 (0.015 g, 0.05 mmol, 1 equiv),
was dissolved in 1 mL of dry dichloromethane. Butylamine (0.006
g, 0.075 mmol, 1.5 equiv) was added to the solution. The reaction
was left stirring under argon at room temperature for 10 h, after
which the solvent was evaporated under reduced pressure. The
1
(
(
1
(
0.083 g, 86%). H NMR (500 MHz, CDCl
3
) δ 10.57 (s, 1H), 6.08
s, 2H), 2.54 (s, 6H), 2.13 (s, 6H); 1 C NMR (125 MHz, CDCl
) δ
93.0, 158.5, 141.5, 135.9, 128.8, 121.8, 30.9, 15.4, 14.8; HRMS
3
3
-
ESI) for C14
15 2 2
H N OBF (M ) calcd 275.11727, found 275.11677;
-1
FTIR 965, 1061, 1190, 1306, 1510, 1558, 1715 cm
.
1
7568 J. AM. CHEM. SOC. 9 VOL. 132, NO. 49, 2010