Metal-free Brønsted acid catalyzed formal [3 + 3] annulation. straightforward synthesis of dihydro-2H-chromenones, pyranones, and tetrahydroquinolinones.
Brønsted acids catalyze the addition of enolizable beta-diketones, beta-ketoesters, and vinylogous amides to alpha,beta-unsaturated aldehydes to lead to substituted chromenones, pyranones, and tetrahydroquinolinones in good yields under mild reaction conditions via a formal [3 + 3] cycloaddition.
Moreau
Julie
J
Sciences Chimiques de Rennes, Catalyse et Organométalliques, UMR 6226, CNRS-Université de Rennes 1, Campus de Beaulieu-35042 Rennes Cedex, France.
Hubert
Claudie
C
Batany
Jessika
J
Toupet
Loic
L
Roisnel
Thierry
T
Hurvois
Jean-Pierre
JP
Renaud
Jean-Luc
JL