Spirocyclic and fused derivatives of maleimide based on intra- and intermolecular reactions of carbonyl ylides from diazocarbonyl compounds

• Published in: Heterocycles Vol. 73; no. 1; pp. 433 - 450
• Main Authors: Nikolaev, Vsevolod V., Schulze, Baerbel, Heimgartner, Heinz, Nikolaev, Valerij A.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier 01.12.2007
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; cycloaddition reaction; 1,3-and 1,5-dipolar electrocyclizations; Rh(II)-carbenoid; CARBENOIDS; diazocarbonyl compound; CYCLOADDITIONS; 1,5-DIPOLAR ELECTROCYCLIZATIONS; THIOCARBONYL-YLIDES; CYCLIZATION; carbonyl ylide; ETHYL DIAZOACETATE
• ISSN: 0385-5414; 1881-0942
• DOI: 10.3987/COM-07-S(U)13

The reaction of maleimide with Rh(II)-ketocarbenoids, derived from acyclic diazocarbonyl compounds, proceeds chemoselectively at the oxygen atom of the imidic C=O group to give carbonyl ylides as reactive inter-mediates. The carbonyl ylide generated from maleimide and ethyl diazoacetate reacts intermolecularly with the double bond of another molecule of maleimide to yield tricyclic spiroadducts via [3+2]-cycloaddition. Intramolecular stabilization is characteristic for carbonyl ylides with two bulky electron-withdrawing groups at the carbanionic center and occurs in two different ways, depending on the structure of the substituents: carbonyl ylides from diazomalonate, which possess two alkoxycarbonyl groups at the carbanionic C-atom, experience a 1,3-dipolar electrocyclization with formation of an oxirane, while carbonyl ylides with at least one a-acyl group, derived from diazoacetoacetate or diazoacetylacetone, undergo an intramolecular 1,5-dipolar electrocyclization to produce 1,3-dioxole derivatives of maleimide.