Fluoride ion catalyzed multicomponent reactions for efficient synthesis of 4H-chromene and N-arylquinoline derivatives in aqueous media

Synthesis and spectral investigation of some new hetaryl‐substituted hydroquinolinone derivatives

“…Despite some hetaryl-substituted hydroquino linone derivatives have been previously reported, [12][13][14] the exact reaction mechanism for formation of these derivatives has not yet been defined in the literature. Thumar and Patel [15] have proposed plausible mechanistic pathway for the synthesis of some quinoline derivatives.…”

Leucine: green and efficient catalyst for the synthesis of 4H-chromenes

“…As a result, in recent years, much research activities in synthetic organic chemistry have been dedicated to the synthesis of 4H-chromenes due to their biological and pharmacological activities. Until now, several methods have been reviewed in the literature for the synthesis of 4H-chromenes that employ various reagents and catalysts such as n-Bu4NF [9], magnetic nanocatalysts [10], lipase [11], mesoporous silica nanoparticles [12], lithium bromide [13], piperidine [14], magnesium oxide [15], and silica-bonded n-propyl-4-aza-1-azoniabicyclo [2.2.2] octane chloride [16]. However, many of these procedures suffer from certain drawbacks such as environmentally unpleasant use of huge organic solvents and hazardous reagents, long reaction time, low yield, costly preparation of catalysts, and stringent reaction conditions.…”

Synthesis of Fe 3 O 4 /Eggshell Nanocomposite and Application for Preparation of Tetrahydrobenzo[b]Pyran Derivatives

“…Several methods for the synthesis of tetrahydrobenzo [b]pyran derivatives have been reported for instance 4H-benzo [b]pyrans were synthesized from α-cyanocinnamonitrile derivatives in a single step reaction which is catalyzed by acid or base [10][11][12]. Several methods stated for the synthesis of these compounds in the presence of catalysts such as sodium bromide [13], hexadecyldimethylbenzylammonium bromide [14], tetramethylammonium hydroxide [15], diammonium hydrogen phosphate [16], fluoride ions [17], magnesium oxide [18], sodium selenite [19], iodine [20], H6P2W12O62·H2O [21], tetrabutylammonium bromide [22], cerium(III) chloride [23].However, each of the above-mentioned method has a drawback such as: long reaction time, severe reaction conditions, use of toxic reagents and low reaction yield. Thus, the development of fast, suitable, and environmentally friendly methods for the synthesis of tetrahydrobenzo [b]pyrans remains essential strategy to overcome stated problems.…”