LETTER
Synthesis of Disulfides Containing a Corrinoid Head Group
1903
Coa,Cob-Di(cyano-kC)-Nc-(11,12-dithiodocosan-1-
yl)cob(III)yrinic Acid-c-amide a,b,d,e,f,g-Hexamethyl Ester
(14b)
(monolayer), or that phase segregation and island forma-
tion occurred. Ellipsometric results also suggest a very
low thickness.40 Since no cobyrinate had been found on
control surfaces, it was concluded that (Cob–C10–S)2 15
formed a monolayer with the disulfide attached onto the
gold substrates.
Yield: 36%; Rf [toluene–MeOH (0.1% HCN) = 10:1]: 0.40. IR
(KBr): 3443w, 3303w, 2925s, 2121w, 1737s, 1662m, 1581s, 1502s
cm–1. UV/Vis (1.13 × 10–5 M, CH2Cl2, lmax, log e): 590 (3.2), 550
(3.81), 516 (3.63), 422 (3.38), 371 (4.29), 356 (sh, 4.02), 318 (3.92),
1
280 (3.95). H NMR: d = 0.83 (t, 3 H), 1.15–1.40 (stack, 39 H),
The synthesis of three novel alkane disulfides with
cobyrinate head groups, 14a,b and 15, is described. The
formation of self-assemblies on Au (100, 111 and poly-
crystalline) from the disulfide 15 with its bulky corrinoid
head groups was established by TOF-SIMS and ESCA
analyses. As a first result of the catalytic acitvity of the Au
electrode coated with 15, Abrantes and coworkers
reported the reduction of O2.40 The STM (scanning tunnel-
ing microscopy) analysis of the surface coating will be
reported elsewhere.49
1.49–1.85 (stack, 14 H), 1.95–2.35 (stack, 13 H), 2.40–3.85 (stack,
14 H), 3.01 (m, 1 H), 3.28 (m, 1 H), 3.62–3.80 (stack , 18 H), 5.51
(s, 1 H), 6.97 (m, 1 H); 13C NMR: d = 14.33 (q), 15.57 (q), 15.58 (q),
17.14 (q), 18.68 (q), 19.51 (q), 20.01 (q), 22.25 (q), 22.90 (t), 25.11
(t), 25.97 (t), 26.04 (t), 27.26 (t), 28.74 (t), 29.39 (t), 29.44 (t), 29.51
(t), 29.52 (t), 29.68 (t), 29.73 (t), 29.89 (t), 31.71 (t), 31.71 (q), 32.11
(t), 32.69 (t), 33.94 (t), 39.38 (t), 39.15 (t), 39.17 (q), 39.79 (t), 41.62
(t), 46.12 (s), 46.93 (s), 47.29 (t), 51.41 (s), 51.86 (q), 51.87 (q),
52.09 (q), 52.11 (q), 52.13 (q), 52.66 (q), 53.79 (q), 56.62 (q), 58.47
(s), 58.95 (d), 74.67 (d), 82.63 (s), 91.64 (d), 101.8 (s), 106.3 (s),
161.35 (s), 163.59 (s), 169.47 (s), 171.39 (s), 171.51 (s), 171.63 (s),
172.51 (s), 172.86 (s), 173.59 (s), 173.83 (s), 175.36 (s), 175.77 (s),
175.89 (s). ESI-MS (CH3OH + 0.1% HCN): C73H112CoN7O13S2
(1418.78) 1440.78 {[M + Na+]+, (3)}, 1393.7 (43), 1392.80 (77),
1391.83 {[M – CN–]+, (100)}, 707.56 {[M – CN– + Na+]2+, (60)},
696.57{([M – CN– + H+]2+ (11)}, 683.13 {[M – 2 CN–]2+ (50)}.
Selected data:
Experimental and analytical data for compounds 4, 5, 8a, 8b (Rf,
mp, IR, 1H NMR, 13C NMR, MS, correct elemental analysis), 10a
(IR, 1H NMR, 13C NMR, TOF-MS) and 10b (1H NMR, 13C NMR)
may be obtained from the author of correspondence.
Bis[Coa,Cob-di(cyano-kC)-Nc,Nc¢-(dithiodidecan-10,1-
diyl)]bis[cob(III)yrinic Acid-c-amide a,b,d,e,f,g-Hexamethyl
Ester] (15)
Coa,Cob-Di(cyano-kC)-Nc-(11,12-dithiooctadec-1-
Yield: 7.4%; Rf [toluene–i-PrOH–MeOH (+0.1% HCN) = 10:1:1]:
0.38; [CH2Cl2–MeOH (+0.1% HCN) = 10:1]: 0.66. IR: 3413w,
2927m, 2854m, 2124w, 1794m, 1736s, 1660m cm–1. 1H NMR: d =
1.10-1.39 (stack, 54 H), 1.49 (s, 6 H), 1.55–1.85 (stack, 18 H), 1.95–
2.87 (stack, 60 H), 3.01(m, 2 H), 3.29 (m, 2 H), 3.58–3.77 (stack, 36
H), 5.52 (s, 2 H), 6.97 (m, 2 H); 13C NMR: d = 15.61 (2q), 15.63
(2q), 17.19 (2q), 18.73 (2q), 19.56 (2q), 20.05 (2q), 22.31 (2q),
25.16 (2t), 26.01 (2t), 26.12 (2t), 27.31 (2t), 28.79 (2t), 29.44 (2t),
29.47 (2t), 29.49 (2t), 29.55 (2t), 29.73 (2t), 29.83 (2t), 29.94 (2t),
31.06 (2t), 31.18 (2t), 31.76 (2q), 32.07 (2t), 32.73 (2t), 33.99 (2t),
39.36 (2t), 39.48 (2d), 40.08 (2t), 41.90 (2t), 46.09 (2s), 46.90 (2s),
47.54 (2t), 51.36 (2s), 51.92 (2q), 51.93 (2q), 52.15 (4q), 52.18 (2q),
52.72 (2q), 53.84 (2d), 56.89 (2d), 58.45 (2s), 58.97 (2d), 74.95
(2d), 82.61 (2s), 91.67 (2d), 102.16 (2s), 106.67 (2s), 129.21 (s),
134.97 (s), 161.35 (2s), 163.56 (2s), 169.46 (2s), 171.37 (2s),
171.49 (2s), 171.61 (2s), 172.49 (2s), 172.85 (2s), 173.57 (2s),
173.81 (2s), 175.35 (2s), 175.76 (2s), 175.88 (2s). UV/Vis ( 8.03 ×
10–6 M, lmax, log e, CH2Cl2): 590 (4.17), 550 (4.11), 515 (3.92), 423
(3.7), 371 (4.62), 356 (sh, 4.33), 318 (4.24), 280 (4.32). ESI-MS
(CH3OH + 0.1% HCN) C106H182Co2N14O26S2 (2490.89): × 10:
2463.12 {[M – CN–]+, (3)}; 1243.8 {[M – CN– + Na+]2+, (12)},
1218.85 {[M – 2 CN–]2+, (100)}, 820.3 {[M – 2CN– + Na+]3+, (20)},
812.9 {[M – 2CN– + H+]3+, (39)}, 804.1 {[M – 3CN–]3+, (9)}.
yl)cob(III)yrinic Acid-c-amide a,b,d,e,f,g-Hexamethyl Ester
(14a)
To a degassed solution of freshly prepared 1350–51 (0.282 g, 0.262
mmol) in 15 mL CH2Cl2 was added 0.12 g (0.28 mmol) 2,2,2-
trichloro-tert-butylchloroformate in 1.2 mL CH2Cl2 and 0.04 mL
Et3N (0.4 mmol) at –10 °C. After 2 h, a suspension of 0.119 g (0.3
mmol) 10a and 0.14 g Et3N in 5 mL CH2Cl2 was added. The mixture
was stirred overnight at r.t., worked up, and the residue was dis-
solved in CH2Cl2 and adsorbed on 7 g silica gel. Flash chromatog-
raphy with CH2Cl2-MeOH (0.1% HCN) = 50:1 gave 0.191 g
(53.5%) 14a. Residual heptamethyl cobyrinate was removed by
TLC with toluene–i-PrOH–MeOH (0.1% HCN) = 10:1:1 as eluent.
Rf [CH2Cl2–MeOH (0.1% HCN) = 40:1] 0.25; [toluene–i-PrOH–
MeOH (0.1% HCN = 10:1:1] 0.38. IR (KBr): 3551m, 3416m,
2953m, 2928s, 2855m, 2120w, 1737s, 1661m, 1581s, 1503s,
1437m, 1199s, 1148s cm–1. UV/Vis (1.981 × 10–5 M in CH2Cl2,
lmax, log e): 590 (3.83) 550 (3.72). 513 (3.51), 424 (3.26), 372
(4.25), 356 (sh, 3.93), 3.16 (3.78), 280 (3.83). 1H NMR: d = 0.85 (t,
J = 7.0, 3 H), 1.10–1.40 (stack, 33 H), 1.47 (s, 3 H), 1.52–1.90
(stack, 12 H), 1.9–2.3 (stack, 15 H), 2.32–2.79 (stack, 16 H), 3.0 (m,
1 H), 3.25–3.35 (m, 1 H), 3.6–3.78 (6s, 18 H), 5.50 (s, 1 H), 6.96 (t,
1 H). 13C NMR: d = 13.9 (q), 15.28 (q), 15.31 (q), 16.87 (q), 18.41
(q), 19.23 (q), 19.72 (q), 21.99 (q), 22.49 (t), 24.81(t), 25.68 (t),
25.77 (t), 26.98 (t), 28.14 (t), 28.46 (t), 29.15 (t), 29.17 (t), 29.20 (t),
29.22 (t), 29.28 (t), 29.45 (t), 29.56 (t), 29.66 (t), 29.68 (t), 30.72 (t),
30.84 (t), 31.39 (t), 31.43 (q), 31.76 (t), 32.39 (t), 33.65 (t), 39.08
(t), 39.11 (t), 39.14 (q), 39.77 (t), 41.59 (t), 46.05 (s), 46.89 (s),
47.23 (t), 51.36 (s), 51.62 (q), 51.84 (q), 51.86 (q), 51.87 (q), 52.41
(q), 53.49 (q), 56.56 (q), 58.43 (s), 58.65 (d), 74.61 (d), 82.59 (s),
91.34 (d), 102.17 (s), 106.67 (s), 129 (s), 135.16 (s), 161.30 (s),
163.53 (s), 169.46 (s), 171.32 (s), 171.49 (s), 171.62 (s), 172.51
(s), 172.86 (s), 173.59 (s), 173.84 (s), 175.32 (s), 175.74 (s), 175.88
(s). ESI-MS (CH3OH + 0.1% HCN) C69H104CoN7O13S2 (MW
1362.67): 1337.71 (38), 1336.76 (74 [M – CN–]+), 1335.8 (100),
679.51 (28, [M – CN– + Na+]2+), 668.58 (0.2, [M – CN– + H+]2+),
655.11 (20, [M – 2CN–]2+).
Acknowledgment
This work has been supported by the Swiss National Science
Foundation (Project No. 20-43565.95), the Bundesamt für Bildung
und Wissenschaft (Project BBW No. 950606) within the European
Research Program TMR (Contract No. ERBFMRXCT 960018) and
the COST program D15 (BBW Project No. 99.0106). We thank D.
Lehmann for preparation of intermediates and A. Schindler for ESI-
MS measurements. We are grateful to Prof. H. Mathieu and his
group for the TOF-SIMS and ESCA measurements of the coated Au
electrodes. Discussions with our colleagues Prof. L. Abrantes,
University of Lisboa and Prof. P. Bigler, University of Bern, are
gratefully acknowledged.
Synlett 2005, No. 12, 1901–1904 © Thieme Stuttgart · New York