Manfred Haber

N-benzoylindole-2,3-quinodimethane: Diels-Alder reactivity and synthetic applications for [b]annellated indoles

Abstract The Diels-Alder reactivity of in situ generated N -benzoylindole-2,3-quinodimethane has been expanded considerably to include reactions with carbon- and hetero-dienophiles which furnish a variety of [ b ]annellated indoles as well as functionalized and annellated carbazoles. The frontier molecular orbital theory was found to be a useful model for the prediction of the experimental results under consideration of reactivity aspects.

Diels-Alder Reactions under Molecular Sieve Catalysis: Enhancement of Reactivity in Cyclization Reactions with N-Benzoylindole-2,3-quinodimethane to Functionalized Carbazoles

In the presence of highly activated molecular sieves (4 A), the Diels-Alder reactivity of in situ generated N-benzoylindole-2,3-quinodimethane is enhanced considerably. Reactions of this species with a variety of carbodienophiles give rise to novel functionalized and [b]annelated carbazole derivatives in a one-pot procedure

Effects of intraocular cefotaxime on the human corneal endothelium.

Purpose: To ascertain whether 0.4 mL of cefotaxime 0.25% applied intracamerally causes toxic alteration of the human corneal endothelium. Methods: In this prospective randomized masked study, 66 patients had cataract extraction using phacoemulsification, a frown incision, and implantation of a poly(methyl methacrylate) intraocular lens. This was followed by intraocular injection of 0.4 mL of cefotaxime 0.25% or balanced salt solution (BSS®). Contact specular microscopy and photography were performed preoperatively and 1 to 4 days and 3 months postoperatively. Results: In the cefotaxime group, the mean endothelial cell count was 2729 cells/mm2 ± 474 (SD) preoperatively, 2520 ± 462 cells/mm2 1 to 4 days postoperatively, and 2560 ± 495 cells/mm2 3 months postoperatively. The mean endothelial cell count in the BSS (control) group was 2657 ± 413 cells/mm2, 2475 ± 384 cells/mm2, and 2486 ± 427 cells/mm2, respectively. There was no significant difference in cell count or morphology between groups (P < .05). Conclusions: Intraocular application of cefotaxime produced no significant changes in endothelial cell count or morphology when compared with application of a control substance. With its broad spectrum of antibiotic activity, cefotaxime might be an appropriate alternative to other intraocularly administered antibiotics in anterior segment surgery for prophylaxis and management of infection.

New Potential DNA Intercalators of the Carbazole Series from Indole-2,3-quinodimethanes: Synthesis, Crystal Structure, and Molecular Modeling with a Watson-Crick Mini-Helix

Summary1-Alkylpyrano[3,4-b]indol-3-ones3 react via a Diels-Alder step with an aryne or N-phenylmaleimide to furnish the new [b]annellated carbazoles4–10 in a one-pot process. In an analogous procedure, the in situ generated N-benzoylindole-2,3-quinodimethane (13) reacted with quinones to furnish the dioxocarbazoles14–16. Compounds4–8 and14–16 with a coplanar skeleton are members of a class of potential DNA intercalators, as has been shown for5 and8 by X-ray structural analysis. On the basis of the geometries determined by X-ray crystallography, the intercalative binding of these molecules with a Watson-Crick mini-helix was predicted by molecular modeling methods.Zusammenfassung1-Alkylpyrano[3,4-b]indol-3-one3 reagieren über einen Diels-Alder-Schritt mit Arin oder N-Phenylmaleinimid zu [b]annellierten Carbazolen4–10 in einer Einstufenreaktion. In analoger Weise reagiert ein in situ erzeugtes N-Benzoylindol-2,3-chinodimethan13 mit Chinonen zu den Dioxocarbazolen14–16. Die Verbindungen4–8 und14–16 gehören infolge ihrer coplanaren Struktur zur Klasse potentieller DNA-Interkalatoren. Auf der Basis von Röntgenstrukturanalysen von5 und8 wird die interkalative Bindung mit einer Watson-Crick Minihelix durch Molecular Modeling vorhergesagt.

A One-Pot Access to [b]Annellated Carbazoles as Potential DNA Intercalators via Diels-Alder Reactions with 1-Alkylpyrano[3,4-b]indol-3-ones

1-Alkylpyrano [3,4-b] indol-3-ones (3) react via a Diels-Alder process with arynes or N-phenylmaleimide to furnish [b] annellated carbazoles (4-10) in a one-pot procedure. Compounds (4-8) with a coplanar framework belong to the class of potential DNA intercalators

DIELS-ALDER-REAKTIONEN VON VINYLINDOLEN MIT ARIN UND 1,4-BENZOCHINONEN : NEUE POTENTIELLE DNA-INTERKALATOREN

SummaryDiels-Alder reactions of 2- and 3-vinylindoles with aryne, 1,4-benzo- and 1,4-naphtho-quinone lead to new six-ring annellated carbazoles. Molecular modeling studies predict that the compounds with coplanar framework are able to intercalate with the B-DNA.