Conjugated heterocumulenes. Synthesis of conjugated carbodiimides and their facile conversion via intramolecular cycloaddition into nitrogen heterocycles, quinoline and pyrido[2,3-b]indole (α-carboline) derivatives
Conjugated heterocumulenes. Synthesis of conjugated carbodiimides and their facile conversion via intramolecular cycloaddition into nitrogen heterocycles, quinoline and pyrido[2,3-b]indole (α-carboline) derivatives
A convenient method is described for the synthesis of conjugated carbodiimides and their application to nitrogen heterocycle synthesis via electrocyclisationâintramolecular DielsâAlder reaction.
Periselective, Lewis acid-induced intramolecular Diels–Alder reaction of conjugated carbodiimides: efficient synthesis of nitrogen heterocycles, indolo[2,3-b]quinolines and pyrido[2,3-b]indole
A suitable Lewis acid has been found that accelerates the intramolecular DielsâAlder reaction of conjugated carbodiimides with high periselectivity control, thus providing an efficient and straightforward procedure for constructing indolo[2,3-b]quinoline and pyrido[2,3-b]indole frameworks.