Spektroskopische und polarographische Untersuchungen an 1,2‐Dicarbonsäureimiden

Abstract

Zum Studium des Substituenteneinflusses an 1,2‐Dicarbonsäureimiden werden ihre IR‐, UV‐, NMR‐Spektren und Polarogramme untersucht. Es wird eine lineare Beziehung der Carbonylfrequenzen, chemischen Verschiebungen und Halbstufenpotentiale zu den HAMMETT‐Konstanten der Substituenten gefunden. Zur Erklärung der Substituenteneffekte an Maleinimiden ist eine gewisse Delokalisation der Imid‐Ring‐Elektronen anzunehmen.

On the Tacticity of Polynorbornenes with 5,6‐endo Pendant Groups That Contain Substituted Aryl Chromophores

“…23 b : 4‐(4‐Bromophenyl)‐4‐aza‐10‐oxa‐ exo ‐tricyclo[5.2.1.0 2,6 ]dec‐8‐ene‐3,5‐dione23 (9.60 g, 30 mmol) in CH 2 Cl 2 (150 mL) was added slowly to a slurry of LiAlH 4 (6.80 g, 180 mmol) in Et 2 O (250 mL), and the mixture was stirred at room temperature for 4 h. H 2 O (21 mL) and NaOH (10 %, 7 mL) were then introduced, and the resulting suspension was filtered. The residue was triturated repeatedly with CH 2 Cl 2 and filtered.…”

“…In a manner similar to that described for the preparation of 18 a, the reaction of LiAlH 4 (4.6 g, 120.0 mmol) and 4-phenyl-4-azatricyclo[5.2.1.0 2,6 ]dec-8-en-3,5-dione [21] (4.8 g, 20.0 mmol) afforded 18 22 c: nBuLi (13 mL, 2.5 m in hexane, 30 mmol) was added dropwise under argon to a solution of 22 b (5.80 g, 20 mmol) in dry THF (140 mL) cooled to À78 8C. After stirring at À78 8C for 1 h, excess CO 2 gas was bubbled into the solution until a white solid ( % 2 h) was precipitated.…”

“…In a manner similar to that described for the preparation of 18 a, the reaction of LiAlH 4 (4.6 g, 120.0 mmol) and 4-phenyl-4-azatricyclo[5.2.1.0 2,6 ]dec-8-en-3,5-dione [21] (4.8 g, 20.0 mmol) afforded 18…”

Carbon-13 NMR and mass spectra of some N-arylmaleimides substituted at the 2-position

“…Carbon-13 NMR Spectra. The C-13 spectra of all samples were recorded in 5-mm NMR sample tubes as 15 % solution in Me2SO-de. All compounds were referenced to internal Me4Si.…”