Efficient Synthesis Of Quinolines Research Articles

Efficient Synthesis of Quinolines from 2‐Aminoaryl Ketones with α‐Methylene Carbonyl Derivatives: Exploiting the Dual Acid Sites of Metal Organic Framework Catalyst

AbstractWe report on the use of heterogeneous metal organic framework (MOF) catalysts for the Friedländer synthesis of 2‐aminoaryl ketone with α‐methylene carbonyl derivatives, a versatile and widely used method for the synthesis of quinoline derivatives. The importance of the Lewis and Brønsted acid sites and their spatial proximity have been explored. Postsynthetic modifications were made to introduce the Brønsted −SO3H acid sites in the pristine MIL‐53(Al). Two modifications were carried out, resulting in two different MOFs: MIL‐53(Al)−NH−(CH2)3−SO3H, in which there is a significant spatial distance between the Lewis and Brønsted sites, and MIL‐53(Al)−SO3H, where the two sites are in close proximity. The availability of sulfonic acid groups has a significant impact on their catalytic performance. The sulfonated MIL‐53(Al) material exhibited a high yield of quinoline derivatives under solventless and mild reaction conditions, with a wide substrate scope and good reusability. Mechanistic studies revealed that the dual acidic sites of the catalysts play an important role in the reaction mechanism.

Efficient synthesis of quinolines through alkali-catalysed cascade Oppenauer oxidation/condensation of amino alcohols with ketones

A transition metal- and ligand-free dehydrogenative coupling between amino alcohols and ketones was developed. Catalysed by base, a series of functional quinolines was synthesized in excellent yields through this easy-to-handle process.

Rhenium-Catalyzed Dehydrogenative Coupling of Alcohols and Amines to Afford Nitrogen-Containing Aromatics and More.

An efficient synthesis of quinolines, pyrimidines, quinoxalines, pyrroles, and aminomethylated aromatic compounds catalyzed by a well-defined Re(I) PNP pincer complex is described. All reactions proceed with liberation of dihydrogen and elimination of water. Under optimized reaction conditions a wide range of organic functional groups are tolerated. This study demonstrates that rhenium catalysts are performing extremely well in dehydrogenative processes with considerably lower catalyst loadings and shorter reaction times when compared to analogous Mn(I) complexes.

An efficient synthesis of quinolines via copper-catalyzed C-N cleavage.

An efficient method to synthesize substituted quinolines from ketones and 2-amino benzylamines is described. Copper-catalyzed C-N cleavage of amines followed by condensation with ketones deliver quinolines in moderate to high yields. The broad scope of substrates and the use of air as the sole oxidant make this transformation very attractive.

An efficient synthesis of quinolines under solvent-free conditions

An efficient synthesis of substituted quinolines has been achieved in a one-pot reaction from o-nitrobenzaldehyde and enolizable ketones using SnCl2·2H2O as the reductant under microwave irradiation without any solvent or catalyst