A straightforward and efficient method for the synthesis of quinolines via Friedländer reaction of 2-aminobenzaldehyde with various ketones or malononitrile in water without using any catalyst at 70 ˚C is reported. catalyst-free - water - Friedländer reaction - ketones - quinolines
A mild, selective and efficient Nazarov cyclization of divinyl ketones catalyzed by phosphomolybdic acid (PMA) is described. The process demonstrates a broad substrate scope with functional group tolerance under short reaction times. PMA supported on silicagel is more efficient than the bulk catalyst and is recycled up to three times without significant activity loss.
Cationic bromonium complex: NBS/P(OPh)3 as an efficient catalyst for Nazarov cyclization
作者:Fenglou Guo、Limin Wang、Song Mao、Chi Zhang、Jianjun Yu、Jianwei Han
DOI:10.1016/j.tet.2012.06.107
日期:2012.9
A general, catalytic method for Nazarovcyclization of dihydropyran derivatives has been developed. Cationic bromonium complex: NBS/P(OPh)3 was identified as an efficientcatalyst for the synthesis of a number of different cyclopentenones in high yields with an excellent level of diastereocontrol.