Rapid access to amino-substituted quinoline, (di)benzofuran, and carbazole heterocycles through an aminobenzannulation reaction.
The use of a powerful aminobenzannulation reaction has been applied for the synthesis of amino-substituted quinolines, dibenzofurans, and carbazoles. The precursors are heterocycles bearing a methyl ketone group ortho to an internal alkyne. They are commercially available or can be obtained in three to four classical and efficient reactions: Vilsmeier-Haack, Sonogashira (diversity point), Grignard, and Ley's oxidation. Upon aminobenzannulation reaction-classical conditions being pyrrolidine neat or in a solvent and 4 A MS-an interesting range of disubstituted quinolines, dibenzofurans, and carbazoles are obtained along with enamine formation in some cases. The reaction is useful since meta-substituted heterocycles are produced and also differs from classical heterocyclic methods which go through closure at the heteroatom-containing ring instead of benzene ring formation.
Tiano
Martin
M
Institut de Chimie et Biochimie Moléculaires et Supramoléculaires (ICBMS), Laboratoire de Synthèse et Méthodologie Organiques (LSMO), Université de Lyon, 43 boulevard du 11 Novembre 1918, Villeurbanne cedex, France
Belmont
Philippe
P