Functionalization of dipyrromethanes via hetero-Diels–Alder reaction with azo- ...

• Author(s): Pereira, Nelson A. M. ; Lemos, Américo ; Serra, Arménio C. ; Melo, Teresa M.V.D. Pinho e
• Date: 2013
• Persistent ID: http://hdl.handle.net/10316/26848
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Dipyrromethanes; Azoalkenes; Nitrosoalkenes; Hetero-Diels–Alder reaction
• Document Type: Article
• Language: English

Description

5,5′-Diethyl- and 5-phenyldipyrromethanes participate in cycloadditions with azo- and nitrosoalkenes giving dipyrromethanes with side chains containing open chain oximes and hydrazones. By controlling reaction stoichiometry it is possible to get mono or 1,9-disubstituted derivatives. The reported methodology gave access to a range of dipyrromethanes with good structural features for various applications. It was demonstrated that reduction of dipyrromethanes containing α-oximino ester groups opens the way to new α-amino esters.