A green one-pot multicomponent synthesis of 4H-pyrans and polysubstituted aniline derivatives of biological, pharmacological, and optical applications using silica nanoparticles as reusable catalyst

Grindstone Chemistry: An Efficient and Green Synthesis of 2-Amino-4H-benzo[b]pyrans

“…The conventional reported synthesis of 4H-pyran derivatives uses piperidine and triethylamine in organic solvents. A variety of other reagents such as HMTAB [22], TEBA, Re(PFO) 3 [23], NaBr [24], S-proline [25], L-proline [26] the use of microwave irradiation [27], infrared radiation [28], KF-basic alumina in dimethylformamide (DMF) [29], ultrasound irradiation [30], aminofunctionalized ionic liquids [31], SBA-15 mesoporous silica [32], silica nanoparticals [33] and ammonium acetate under microwave irradiation [34] were found to catalyze this reaction. Most of the mentioned methods have at least one of the limitations such as low yield, long reaction times, effluent pollution, harsh reaction conditions, formation of by-products, the use of toxic organic solvents, the use of additional instruments such as ultra sound and tedious workup procedures.…”

Synthesis and <i>in vitro</i> antimicrobial evaluation of 5-amino-7-aryl-6-cyano-4<i>H</i>- pyrano[3,2,<i>b</i>]pyrrole derivatives catalyzed by reusable ZrOCl₂•8H₂O

“…Recently, 4H-pyran derivatives were synthesized using different catalysts like magnesium oxide [14], SB-DABCO [15], silica nanoparticles [16], ionic liquid [bmim]BF 4 [17], Baker's yeast [18] and amino functionalized ionic liquid [19]. However, only few reports are available for the synthesis of 5-amino-7-aryl-6-cyano-4H-pyrano [3,2-b]pyrrole derivatives [20][21][22][23][24].…”

Synthesis of 4H-Pyran Derivatives via a Green One-Pot Multicomponent Reaction Catalyzed by CuFe2O4¬ Magnetic Nanoparticles as a Reusable Catalyst

“…On the other hand, catalysts are powerful tools to improve reaction conditions. Application of nanoscience in this field leads to a wide range of academic and industrial researches to obtain green procedures [8]. http://www.sciforum.net/conference/ecsoc-18 3…”