SYNTHESIS OF CHIRAL PORPHYRINS AND THEIR USE IN PHOTOCHEMICAL OXIDATION OF CARBONYL COMPOUNDS
9
515 (7.42 × 103), 546 (5.19 × 103), 595 (2.41 × 103), 644
(1.48 × 103). 1H NMR (500 MHz; CDCl3): dH, ppm -2.55
(2H, s, pyrrole-NH), 1.59 (9H, s, -C(CH3)3), 1.84–1.85
(18 H, m, Ar-CH3), 1.98–2.16 (4H, m, -CH2-), 2.62–2.74
(9H, s, -Ar-CH3), 3.48–3.58 (2H, m, -CH2-), 4.63 (1H, br
s, -CH-), 7.24–7.27 (6H, s, Ar-H), 7.91 (2H, d, J = 7.9
Hz, Ar-H), 8.14 (2H, d, J = 7.7 Hz, Ar-H), 8.62 (4H, s,
b-H), 8.66–8.69 (2H, m, b-H), 8.80 (2H, d, J = 4.5 Hz,
b-H), 9.89 (1H, br s, NH). 13C NMR (125 MHz, CDCl3):
dc, ppm 21.4, 21.6, 21.7, 21.9, 28.5, 29.69, 47.4, 81.1,
117.8, 117.9, 127.6, 127.7, 130.5, 134.9, 137.6, 138.2,
138.4, 139.4, 149.8, 170.3. HRMS (ESI): m/z 953.5124
(calcd. for [M + H]+ 953.5118).
General procedure for Boc deprotection. To a cooled
1:1 mixture of TFA and DCM (2.5 mL) with 1% of
PhOMe was added compound 7 (50 mg, 0.05 mmol). The
resulting mixture was stirred for 3 h at rt and then poured
into DCM and washed with satd aq. NaHCO3 (2 × 25 mL),
water (2 × 25 mL), and brine (25 mL). The organic layer
was dried with Na2SO4, filtered and concentrated.
7.8 Hz, Ar-H), 7.88 (1H, d, J = 6.3 Hz, Ar-H), 8.24–8.26
(2H, m,Ar-H), 8.62 (4H, s, b-H), 8.66–8.67 (2H, m, b-H),
8.78–8.79 (2H, m, b-H), 10.09 (1H, s, NH). 13C NMR
(125 MHz, CDCl3): dc, ppm 21.4, 21.6, 21.7, 21.8, 26.0,
30.7, 47.2, 61.0, 117.7, 117.9, 118.5, 118.8, 125.1, 127.2,
127.7, 128.8, 130.5, 130.8, 136.3, 137.6, 138.1, 138.3,
139.41, 139.44, 139.5, 142.8, 172.7. HRMS (ESI): m/z
853.4593 (calcd. for [M + H]+ 853.4594).
5,10,15-Tris(mesityl)-20-(4-prolinanilidylphenyl)-
21,23H-porphyrin (8c) was prepared from porphyrin 7c
(52mg, 0.05mmol. RecrystallizationfromMeOHgave8c
as a purple solid. Yield 41 mg (88%), Rf = 0.83 (CHCl3 –
MeOH, 1:1 (v/v)). UV-vis (CHCl3): lmax, nm (e, M-1cm-1)
419 (2.22 × 105), 514 (1.08 × 104), 541 (7.60 ×
1
103), 591 (3.47 × 103), 648 nm (1.95 × 103). H NMR
(500 MHz; CDCl3): dH, ppm -2.55 (2H, s, pyrrole-NH),
1.84–1.85 (18H, m, Ar-CH3), 1.89–2.00 (2H, m, -CH2-),
2.21–2.28 (1H, m, -CHH-), 2.39–2.45 (1H, m, -CHH-),
2.61 (9H, s, Ar-CH3), 3.18–3.27 (2H, m, -CH2-), 4.21
(1H, s, -CH-), 7.26 (6H, s, Ar-H), 8.02 (2H, d, J = 8.2 Hz,
Ar-H), 8.15 (2H, d, J = 8.3 Hz, Ar-H), 8.62 (4H, s, b-H),
8.66 (2H, d, J = 4.6 Hz, b-H), 8.79 (2H, d, J = 4.5 Hz,
b-H), 10.29 (1H, s, NH). 13C NMR (125 MHz, CDCl3):
dc, ppm 21.4, 21.6, 21.7, 26.3, 30.9, 47.5, 61.2, 115.3,
117.6, 117.7, 117.9, 118.8, 120.6, 127.7, 129.6, 134.9,
137.5, 137.6, 137.9, 138.2, 138.4, 139.4, 173.2. HRMS
(ESI): m/z 853. 4604 (calcd. for [M + H]+ 853.4594).
5,15-Bis(mesityl)-10,20-bis(3-nitrophenyl)-21,23H-
porphyrin (10). To a mixture of 3-nitrobenzaldehyde (4b,
288 mg, 1.90 mmol, 10-2 M) and 5-mesityldipyrromethane
(9, 500 mg, 1.89 mmol, 10-2 M) in dry DCM (200 mL)
was added TFA (0.26 mL, 3.4 mmol, 1.8 × 10-2 M). The
resulting mixture was stirred for 30 min at rt and then
DDQ (474 mg, 2.09 mmol) was added. The reaction
mixture was stirred for 1 h at rt and then Et3N (0.50 mL,
3.6 mmol) was added. It was then concentrated to about
5 mL, and silica gel (3–5 g) was added. The slurry was
further dried to afford a dark powder. The crude product
was purified by flash chromatography on silica gel
(toluene). Recrystallization from MeOH gave porphyrin
10 as a purple solid. Yield 299 mg (20%), Rf = 0.47 (30%
hexane in CHCl3). Anal. calcd. for C50H40N6O4 + H2O: C,
74.42; H, 5.25; N, 10.42%. Found: C, 74.58; H, 5.26; N,
10.17. UV-vis (CHCl3): lmax, nm (e, M-1cm-1) 420 (1.05 ×
105), 516 (5.69 × 103), 552 (2.36 × 103), 592 (1.66 × 103),
648 (6.94 × 102). 1H NMR (400 MHz; CDCl3): dH, ppm
-2.63 (2H, s, pyrrole-NH), 1.84 (12H, m, Ar-CH3), 2.62
(6H, s, Ar-CH3), 7.29 (4H, s, Ar-H), 7.92 (2H, t, J = 8.0
Hz, Ar-H), 8.56 (2H, d, J = 7.2 Hz, Ar-H), 8.65 (2H, dd,
J = 8.4, 1.2 Hz, Ar-H), 8.73–8.76 (8H, dd, J = 2.8, 4.8 Hz,
b-H), 9.09 (2H, s,Ar-H).13C NMR (100 MHz, CDCl3): dc,
ppm 21.2, 21.4, 21.6, 116.3, 119.3, 123.0, 127.7, 127.8,
127.9, 128.0, 128.1, 128.2, 129.0, 130.9, 137.8, 138.0,
139.2, 139.3, 139.4, 139.6, 143.6, 146.9. HRMS (ESI):
m/z 789.3190 (calcd. for [M + H]+ 789.3189).
5,10,15-Tris(mesityl)-20-(2-prolinanilidylphenyl)-
21,23H-porphyrin (8a) was prepared from porphyrin 7a
(56mg,0.05mmol).RecrystallizationfromDCM–pentane
gave 8a as a purple solid. Yield 41 mg (83%), Rf = 0.79
(CHCl3 – MeOH, 1:1, (v/v)). Anal. calcd. for C58H56N6O +
H2O: C, 79.97; H, 6.71; N, 9.65%. Found: C, 79.92; H,
6.98; N, 9.35. UV-vis (CHCl3): lmax, nm (e, M-1cm-1) 419
(3.63 × 105), 515 (1.69 × 103), 544 (6.11 × 103), 590 (5.39 ×
1
103), 647 (2.87 × 103). H NMR (500 MHz; CDCl3):
dH, ppm -2.49 (2H, s, pyrrole-NH), 0.70–0.79 (1H, m,
-CHH-), 0.95–0.99 (2H, m, -CH2-), 1.40–1.44 (1H, m,
-CHH-), 1.55–1.62 (1H, m, -CHH-), 1.69–2.05 (19H, m,
Ar-CH3, -CHH-), 2.62 (9H, s, Ar-CH3), 3.20 (1H, dd, J =
8.8, 3.9 Hz, -CH-), 7.23–7.30 (6H, m, Ar-H), 7.41 (1H,
t, J = 7.4 Hz, Ar-H), 7.78 (1H, t, J = 7.8 Hz, Ar-H), 7.83
(1H, d, J = 7.5 Hz, Ar-H), 8.64–8.71 (8H, m, b-H), 8.89
(1H, d, J = 8.3 Hz, Ar-H), 9.86 (1H, s, NH). 13C NMR
(125 MHz, CDCl3): dc, ppm 21.4, 21.51, 21.55, 21.61,
21.64, 21.8, 22.0, 25.2, 30.4, 45.6, 60.5, 113.4, 115.3,
118.1, 118.2, 118.4, 119.6, 122.4, 127.7, 127.8, 127.9,
129.4, 129.5, 131.3, 135.2, 137.8, 138.0, 138.1, 138.5,
139.0, 139.1, 139.5, 139.6, 139.7, 173.4. HRMS (ESI):
m/z 853.4590 (calcd. for [M + H]+ 853.4588).
5,10,15-Tris(mesityl)-20-(3-prolinanilidylphenyl)-
21,23H-porphyrin (8b) was prepared from porphyrin
7b (50 mg, 0.05 mmol). Recrystallization from DCM –
pentane gave 8b as a purple solid.Yield 30 mg (70%), Rf =
0.59 (10% MeOH in CHCl3).Anal. calcd. for C58H56N6O +
H2O: C, 79.97; H, 6.71; N, 9.65%. Found: C, 80.41; H,
6.69; N, 9.22. UV-vis (CHCl3): lmax, nm (e, M-1cm-1) 418
(3.47 × 105), 516 (1.67 × 103), 541 (1.02 × 103), 592 (5.46 ×
103), 643 (1.02 × 103). 1H NMR (500 MHz; CDCl3): dH,
ppm -2.55 (2H, s, pyrrole-NH), 1.68–1.78 (2H, m, -CH2-),
1.83–1.84 (15H, m, Ar-CH3), 1.89 (3H, s, Ar-CH3),
2.06–2.12 (1H, m, -CHH-), 2.22–2.29 (1H, m, -CHH-),
2.60 (9H, s, Ar-CH3), 2.93–3.04 (2H, m, -CH2-), 4.00–
4.03 (1H, m, -CH-), 7.26 (6H, s, Ar-H), 7.64 (1H, t, J =
5,15-Bis(mesityl)-10,20-bis(3-aminophenyl)-21,
23H-porphyrin (11). To a solution of porphyrin 10
Copyright © 2014 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2014; 18: 9–13