Download PDF
Synlett 2008(20): 3213-3215  
DOI: 10.1055/s-0028-1087242
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Chlorins Extended by Highly Substituted Double Bonds

Frank Dullweber, Franz-Peter Montforts*
Institut für Organische Chemie, FB2, Universität Bremen, Leobener Straße NW2C, 28359 Bremen, Germany
Fax: +49(421)2183720; e-Mail: mont@chemie.uni-bremen.de;
Further Information

Publication History

Received 5 September 2008
Publication Date:
24 November 2008 (online)

    Permissions and Reprints All articles of this category

Abstract

Chlorins with highly substituted exocyclic double bonds extending the chromophoric system were synthesized starting from the readily accessible oxochlorin. After sulfurization of the keto function of oxochlorin 7 the formed thioketo chlorin 8 underwent Barton olefination with diazo compounds.

Key words

chlorins - Barton olefination - diazo compounds - extended chromophore

    References and Notes

  • 1a Monforts F.-P. Glasenapp-Breiling M. Kusch D. In Houben-Weyl   Vol. E9d:  Schaumann E. Thieme; Stuttgart: 1998.  p.577-716  
    Google Scholar
  • 1b Montforts F.-P. Gerlach B. Höper F. Chem. Rev.   1994.  94:  p.327 
    Google Scholar
  • 1c Montforts F.-P. Glasenapp-Breiling M. In Progress in Heterocyclic Chemistry   Vol. 10:  Gribble GW. Gilchrist TL. Pergamon; Oxford: 1998.  p.1-24  
    Google Scholar
  • 1d Galezowski M. Gryko DT. Curr. Org. Chem.  2007,  11:  1310 
    Google Scholar
  • 1e Montforts F.-P. Glasenapp-Breiling M. In Progress in the Chemistry of Organic Natural Products   Vol. 84:  Herz W. Falk H. Kirby GW. Springer; New York: 2002.  p.1-51  
    Google Scholar
  • 2a The Photosynthetic Reaction Center   Deisenhofer J. Norris JR. Academic Press; New York: 1993. 
    Google Scholar
  • 2b Gust D. Moore TA. In Photoinduced Electron Transfer III   Mattay J. Springer; Berlin: 1991.  p.105-151  
    Google Scholar
  • 2c Wasielewski MR. Chem. Rev.  1992,  92:  435 
    Google Scholar
  • 2d Kurreck H. Huber M. Angew. Chem., Int. Ed. Engl.  1995,  34:  849 
    Google Scholar
  • 3a van den Bergh H. Cornaz P. Nachr. Chem., Tech. Lab.  1992,  33:  582 
    Google Scholar
  • 3b Dougherty TJ. Adv. Photochem.  1992,  17:  275 
    Google Scholar
  • 3c Bonnett R. Nizhnik AM. White SG. Beerenbaum MC. J. Photochem. Photobiol., B  1990,  6:  29 
    Google Scholar
  • 4a Montforts F.-P. Angew. Chem., Int. Ed. Engl.  1981,  20:  778 
    Google Scholar
  • 4b Montforts F.-P. Schwartz UM. Liebigs Ann. Chem.  1985,  1228 
    Google Scholar
  • 4c Jacobi PA. Lanz S. Gosh I. Leung SH. Loewer F. Pippin D. Org. Lett.  2001,  3:  831 
    Google Scholar
  • 4d O’Neal WG. Jacobi PA. J. Am. Chem. Soc.  2008,  130:  1102 
    Google Scholar
  • 4e Ptaszek M. Mc. Dowell BE. Taniguchi M. Kim H.-J. Lindsey JS. Tetrahedron  2007,  63:  3826 
    Google Scholar
  • 4f Taniguchi M. Ptaszek M. Mc. Dowell BE. Lindsey JS. Tetrahedron  2007,  63:  3840 
    Google Scholar
  • 4g Taniguchi M. Ptaszek M. Mc. Dowell BE. Lindsey JS. Tetrahedron  2007,  63:  3580 
    Google Scholar
  • 4h Mutiah C. Taniguchi M. Kim H.-J. Schmidt I. Kee HL. Holten D. Bocian DF. Lindsey JS. Photochem. Photobiol.  2007,  83:  1513 
    Google Scholar
  • 4i Mineham TG. Kishi Y. Tetrahedron Lett.  1997,  38:  6811 
    Google Scholar
  • 5a Fischer H. Halbig P. Walach B. Justus Liebigs Ann. Chem.  1927,  452:  268 
    Google Scholar
  • 5b Bonnett R. Dimsdale MJ. Stephanson GF. J. Chem. Soc. C  1969,  564 
    Google Scholar
  • 5c Chang CK. Sotiriou C. J. Org. Chem.  1985,  50:  4989 
    Google Scholar
  • 5d Inhoffen HH. Nolte W. Justus Liebigs Ann. Chem.  1969,  725:  167 
    Google Scholar
  • 5e Montforts F.-P. Meier A. Scheurich G. Haake G. Bats JW. Angew. Chem., Int. Ed. Engl.  1992,  31:  1592 
    Google Scholar
  • 5f Bats JW. Haake G. Meier A. Montforts F.-P. Scheurich G. Liebigs Ann.  1995,  1617 
    Google Scholar
  • 5g Romanowski F. Mai G. Kusch D. Montforts F.-P. Bats JW. Helv. Chim. Acta  1996,  79:  1572 
    Google Scholar
  • 5h Micklefield J. Beckmann M. Mackman RL. Block MH. Leeper FJ. Battersby AR. J. Chem. Soc., Perkin Trans. 1  1997,  2123 
    Google Scholar
  • 6a Barton DHR. Willis BJ. J. Chem. Soc., Perkin Trans. 1  1972,  305 
    Google Scholar
  • 6b Barton DHR. Guziec FS. Shahak I. J. Chem. Soc., Perkin Trans. 1  1974,  1794 
    Google Scholar
  • 6c Back TG. Barton DHR. Britten-Kelley MR. Guziec FS. J. Chem. Soc., Perkin Trans. 1  1976,  2079 
    Google Scholar
  • 6d Buter J. Wassenaar S. Kellogg RM. J. Org. Chem.  1972,  37:  4045 
    Google Scholar
  • 7 Scheibje S. Pedersen BS. Lawesson S.-O. Bull. Soc. Chim. Belg.  1978,  87:  229 
    Google Scholar
  • 8 Barton DHR. Guziec FS. Shahak I. J. Chem. Soc., Perkin Trans. 1  1974,  1794 ; CAS for diazodiphenyl-methane: 833-40-9
    CrossrefGoogle Scholar
  • 9a Baltzly R. Mehta NB. Russel PB. Brooks RE. Grivsky EM. Steinberg AM. J. Org. Chem.  1961,  26:  3669 
    Google Scholar
  • 9b Schoenberg A. Awad WI. Latif N. J. Chem. Soc.  1951,  1368 ; CAS for diazofluorene: 832-80-4
    Google Scholar
10

Procedure for the Preparation of the Chlorin Thioketone 8
Diethylenglycol dimethyl ether (5 mL) was added by a syringe to a mixture of 7 (76.9 mg, 0.155 mmol) and Lawesson’s reagent (96.6 mg, 0.239 mmol) placed in a flask equipped with a reflux condenser and a septum. The mixture was stirred for 2.5 h at 150 ˚C under argon. After cooling to r.t. the mixture was transferred by a small volume of CH2Cl2 into a 50 mL round-bottom flask, and the solvent was removed at 80 ˚C in high vacuum by Kugelrohr distillation. The residue was chromatographed on silica gel with a slice of 2 cm alumina on top with CH2Cl2-PE (8:2). The light-green main fraction was collected and the solvent was removed in vacuo. After isothermic crystallization from CH2Cl2-n-pentane 8 (73.9 mg, 0.145 mmol, 93.5%) was obtained.

11

Typical Procedure for the Preparation of Chlorin Derivatives 9-11
Compound 8 (96.3 mg, 0.188 mmol) and 9-diazofluorene (72.3 mg, 0.376 mmol, 2 equiv) were dissolved under argon in 13 mL of anhyd THF. After stirring for 30 min at r.t. the reaction mixture was refluxed for 60 min. Then, tris(2-cyanoethyl)phosphine (72.6 mg, 0.376 mmol) was added and refluxing was continued for further 3 h. The reaction mixture was diluted with CH2Cl2 and the organic layer was washed with H2O (50 mL). The organic extract was dried by filtration over cotton wool and evaporated in vacuo. The residue was chromatographed over alumina (activity II-III) first with PE and then with CH2Cl2-PE (1:1) giving a crude product which was again chromatographed on silica gel with CH2Cl2-PE (1:1) to yield after evaporation of the solvent the light-green product. Isothermic crystallization from chloroform-n-pentane yielded chlorin 11 (71.8 mg, 0.112 mmol, 60%).

12

All compounds show correct spectroscopic and analytic data.

Selected Spectroscopic and Analytic Data for Compounds 8-11
Compound 8: mp >350 ˚C. TLC: silica gel, CH2Cl2-PE (8:2): R f  = 0.74. ¹H NMR (360 MHz, CDCl3): d = 1.93 (s, 6 H, 3-CH3), 3.16, 3.17, 3.19, 3.21, 3.22 (5 s, 18 H, 7-, 8-, 12-, 13-, 17-, 18-CH3), 8.57, 9.13, 9.19, 9.81 (4 s, 4 H, 5-, 10-, 15-, 20-H). UV/Vis (CHCl3): lmax (lg e) = 354 mm (4.586), 400 (4.665), 454 (4.652), 551 (4.040), 591 (4.044), 690 (4.605). IR (KBr): 1222 cm-¹ (s, n, C=S). MS (EI, 70 eV, 286 ˚C): m/z (%) = 514 (10), 513 (17), 512 (47), 511 (33), 510 (100) [M(58Ni)+], 497 (25), 496 (19), 495 (51) [M+ - CH3], 480 (38) [M+ - 2 CH3], 465 (11) [M+ - 3 CH3]. HRMS: m/z calcd for C28H28N4S58Ni: 510.13882; found: 510.13907. Anal. calcd for C28H28N4SNi + 0.1 CH2Cl2: C, 64.93; H, 5.45; N, 10.78; S, 6.17. Found: C, 64.97; H, 5.41; N, 10.5; S, 6.26.
Compound 9: mp >350 ˚C. TLC: silica gel, CH2Cl2-PE (1:2): R f  = 0.63. ¹H NMR (360 MHz, CDCl3/20 mL pyridine-d 5): d = 1.89 (s, 6 H, 3-CH3), 3.13, 3.14, 3.19, 3.21, 3.22 (5 s, 18 H, 7-, 8-, 12-, 13-, 17-, 18-CH3), 5.75 (s, 1 H, 2-CH), 6.46 (s, 1 H, 2-CH), 8.00, 8.53, 8.61, 8.96 (4 s, 4 H, 5-, 10-, 15-, 20-H). UV/Vis (CHCl3): lmax (lg e) = 401 nm (4.980), 577 (4.102), 624 (4.638). MS (EI, 70 eV, 255 ˚C): m/z (%) = 495 (13), 494 (39), 493 (26), 492 [84, M(58Ni)+], 479 (44), 478 (40), 477 (100) [M+ - CH3], 476 (14), 475 (12), 461 (12), 246 (11), 238 (11), and fragment ions of lower mass. HRMS: m/z calcd for C29H30N4 58Ni: 492.18220; found: 491.18240.
Compound 10: mp >350 ˚C. TLC: silica gel, PE-EtOAc (9:1): R f  = 0.41. ¹H NMR (360 MHz, CDCl3/20 mL pyridine-d 5): d = 1.74 (s, 6 H, 3-CH3), 2.54, 3.03, 3.07, 3.15, 3.16 (5 s, 18 H, 7-, 8-, 12-, 13-, 17-, 18-CH3), 7.04-7.17 (m, 4 H, aryl H), 7.41-7.55 (m, 4 H, aryl H), 7.88, 8.01, 9.01, 9.05 (4 s, 4 H, 5-, 10-, 15-, 20-H). UV/Vis (CHCl3): lmax (lg e) = 415 nm (4.959) 556 (4.203), 645 (4.647). MS (DCI, positive, NH3): m/z (%) = 649 (10), 648 (24) 647 (54), 646 (55), 645 (100) [MH+]. MS (DCI, negative, NH3): m/z (%) = 648 (10), 647 (20), 646 (47), 645 (43), 644 (99) [M-], and fragments of lower mass, 96 (100). HRMS: m/z calcd for C41H38N4 58Ni: 644.24480; found: 644.24500.
Compound 11: mp >350 ˚C, TLC: silica gel, CH2Cl2-PE (1:1): R f  = 0.58. ¹H NMR (360 MHz, C6D6): d = 1.97, 2.46 (2 s, 6 H, 3-CH3), 2.66, 2.82, 2.87, 2.95, 2.98, 2.99 (6 s, 18 H, 7-, 8-, 12-, 13-, 17-, 18-CH3), 6.48 (ddd, ³ J = 8.1 Hz, ³ J = 7.0 Hz, 4 J = 1.1 Hz, 1 H, aryl H), 7.03 (ddd, ³ J = 7.6 Hz, ³ J = 7.0 Hz, 4 J = 1.1 Hz, 1 H, aryl H), 7.25-7.32 (m, 2 H, aryl H), 7.59 (d, ³ J = 7.0 Hz, 1 H, aryl H), 7.68-7.70 (m, 1 H, aryl H), 7.79 (d, ³ J = 8.6 Hz, 1 H, aryl H), 8.45-8.47 (m, 1 H, aryl H), 8.02, 9.12, 9.16, 9.68 (4 s, 4 H, 5-, 10-, 15-, 20-H). UV/Vis (CHCl3): lmax (lg e) = 344 nm (4.618), 444 (4.680), 590 (4.123), 687 (4.683). MS (DCI, negative, NH3): m/z (%) = 646 (12), 645 (28), 644 (46), 643 (51), 642 (100) [M-]. HRMS: m/z calcd for C41H36N4 58Ni: 642.22937; found; 642.22907.