Synlett 2004(7): 1291-1293  
DOI: 10.1055/s-2004-822916
LETTER
© Georg Thieme Verlag Stuttgart · New York

Novel Diels-Alder and Thermal [4+4] Cycloadditions of Corroles

Joana F. B. Barata, Ana M. G. Silva, Maria A. F. Faustino, Maria G. P. M. S. Neves, Augusto C. Tomé, Artur M. S. Silva, José A. S. Cavaleiro*
Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
e-Mail: jcavaleiro@dq.ua.pt;
Further Information

Publication History

Received 21 January 2004
Publication Date:
28 April 2004 (online)

Abstract

Corroles participate in Diels-Alder and in thermal [4+4] cycloaddition reactions with pentacene to yield novel barrelene-fused corroles.

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Corrole 1 was prepared by following the procedure described in ref. 8.

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Spectroscopic data for 2: 1H NMR (300 MHz, CDCl3): δ = 9.40 (d, 1 H, J = 4.1 Hz, H-18), 8.69 (d, 1 H, J = 4.1 Hz, H-17), 8.75 and 8.53 (2 d, 2 H, J = 4.7 Hz, H-7,8 or H-12,13), 8.60 and 8.41 (2 d, 2 H, J = 4.4 Hz, H-7,8 or H-12,13), 8.08 (s, 2 H, H-2′,14′), 7.70 (s, 2 H, H-7′,9′), 7.68-7.65 and 7.31-7.28 (2 m, 8 H, H-6′,10′,3′,13′ and H-5′,11′,4′,12′), 7.06 (s, 1 H, H-1′), 5.69 (s, 1 H, H-8′). 13C NMR (75 MHz, CDCl3, based on the HSQC and HMBC spectra): δ = 129.5 (C-β), 127.9 (C-β), 127.5 (C-6′,10′,3′,13′), 126.1 (C-5′,11′,4′,12′), 125.8 (C-β), 125.2 (C-β), 123.1 (C-17), 122.8 (C-2′,14′), 122.4 (C-7′,9′), 117.0 (C-18). HRMS-FAB [M]+: m/z = 1072.1698 (calcd for C59H23N4F15: 1072.1683). UV/Vis (CH2Cl2): λmax (log ε) = 411 (5.82), 567 (5.07), 609 nm (4.88).

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Spectroscopic data for 3: 1H NMR (300 MHz, CDCl3): δ = 8.66 and 8.43 (2 d, 4 H, J = 4.7 Hz, H-7,13 and H-8,12), 8.39 (s, 4 H, H-2′,14′,7′′,9′′), 7.81 (s, 4 H, H-7′,9′,2′′,14′′), 7.82-7.80 (m, 4 H, H-6′,10′,3′′,13′′), 7.79-7.76 (m, 4 H, H-13′,3′,6′′,10′′), 7.56 (s, 2 H, H-1′,8′′), 7.47-7.39 (m, 8 H, H-4′,12′,5′′,11′′ and H-5′,11′,4′′,12′′), 5.78 (s, 2 H, H-8′,1′′). 13C NMR (75 MHz, CDCl3): δ = 141.7 and 141.6 (C-1′a,7′a,8′a,14′a,1′′a,7′′a,8′′a,14′′a), 138.0 (C-2,3,17,18), 131.9 and 131.8 (C-2′a,6′a,9′a,13′a,2′′a,6′′a,9′′a,13′′a), 128.0 (C-7,13 or C-8,12), 127.7 and 127.5 (C-6′,10′,3′′,13′′), 126.9 (C-7,13 or C-8,12), 126.35 and 126.29 (C-4′,12′,5′′,11′′ and C-5′,11′,4′′,12′′), 122.7 (C-2′,14′,7′′,9′′), 122.6 (C-7′,9′,2′′,14′′), 50.4 (C-1′,8′′), 49.5 (C-8′,1′′). HRMS (ES) [M + H]+: m/z = 1349.2747 (calcd for C81H36N4F15: 1349.2695). UV/Vis (CH2Cl2): λmax (log ε) = 415 (5.14), 573 (4.44), 612 nm (4.23).

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Spectroscopic data for 5: 1H NMR (300 MHz, CDCl3): δ = 8.64 (d, 2 H, J = 4.5 Hz, H-7,13 or H-8,12), 8.61 (s, 2 H, H-3,17), 8.47 (d, 2 H, J = 4.5 Hz, H-7,13 or H-8,12), 8.57 (s, 2 H, H-3,17), 8.19 (s, 4 H, H-2′,7′,9′,14′), 7.72-7.69 and 7.28-7.25 (2 m, 8 H, H-3′,6′,10′,13′ and H-4′,5′,11′,12′), 6.68 (s, 2 H, H-1′,8′). 13C NMR (75 MHz, CDCl3, based on the HSQC and HMBC spectra): δ = 138.0 (C-1′a,7′a,8′a,14′), 132.6 (C-2′a,6′a,9′,13′), 127.5 (C-2′,7′,9′,14′), 127.2 (C-3′,6′,10′,13′), 126.0 (C-4′,5′,11′,12′), 125.0 and 124.7 (C-7,13 and C-8,12), 115.6 (C-1′,8′). HRMS-FAB [M + H]+: m/z = 1073.1791 (calcd for C59H24N4F15: 1073.1761). UV/Vis (CH2Cl2): λmax (log ε) = 424 (5.01), 565 (4.07), 615 nm (3.91).

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Examples of thermal [4+4] cycloaddition reactions have been reported in the literature. In some cases [4+4] cycloadditions compete with Diels-Alder reactions. [34-37]