A Novel Colorimetric and Fluorescent Chemosensor for Anions Involving PET and ICT Pathways
摘要:
A novel colorimetric and fluorescent chemosensor ADDTU-1 bearing dual receptor sites, which shows specific optical signaling for AcO-, H2PO4-, and F- over other anions and dual response toward AcO- and F- via PET and ICT mechanisms, is described.
Aldonitrones as Aldehyde Equivalents: An Efficient, Green, and Novel Protocol for the Synthesis of 1,8-Dioxo-octahydroxanthenes
摘要:
A novel, self-catalyzed, solvent-free, microwave-enhanced, green, and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes and bis-5,5-dimethyl-1,3-cyclohexanediones by condensing aldo-nitrones (imine oxide) and dimedone (5,5-dimethyl-1,3-cyclohexanedione) under microwave irradiation is disclosed. Product formation (viz. xanthenes and bis-5,5-dimethyl-1,3-cyclohexanediones) is dependent on reaction conditions. The entire process is green and sustainable in terms of solvents, chemicals, reaction procedure, and yields. A plausible reaction mechanism of this reaction is also proposed. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) for full experimental and spectral details.
Merging supramolecular catalysis and aminocatalysis: amino-appended β-cyclodextrins (ACDs) as efficient and recyclable supramolecular catalysts for the synthesis of tetraketones
作者:Yufeng Ren、Bo Yang、Xiali Liao
DOI:10.1039/c6ra01002d
日期:——
β-CD were synthesized and employed in the catalytic synthesis of a series of tetraketones as supramolecular catalysts in water for the first time. Yields of 58–97% were obtained with up to 30 examples of substrate. The catalyst could be recycled easily, while a 92% yield and 84% rate of catalyst recovery could be achieved after 8 cycles of catalyst recycling. Moreover, a catalytic mechanism merging
SiO}_2}}\) nanoparticles (NPs) as an eco-friendly, efficient and reusable catalyst in the synthesis of 2,3-dihydro-1H-perimidines as well as tetraketones. For tetraketones syntheses, a simple tandem Knoevenagel condensation following Michael addition procedure is performed by the reaction between benzaldehydes and 5,5-dimethyl-1,3-cyclohexanediones under solvent-free condition using \(\hbox SiO}_2}}\)
ABSTRACT A new route of Knoevenagel condensation of aromatic aldehydes with Meldrum's acid, barbituric acid and dimedone in the presence of cetyltrimethyl ammonium bromide at room temperature in water is described.
A Green and Highly Efficient Protocol for Catalyst-free Knoevenagel Condensation and Michael Addition of Aromatic Aldehydes with 1,3-Cyclic Diketones in PEG-400
作者:Nemati Firouzeh、Kiani Hossein
DOI:10.1002/cjoc.201100005
日期:2011.11
A convenient, highlyefficient and green approach for synthesis of tetraketones from aromaticaldehydes with dimedone and 1,3‐indanedione at room temperature in PEG‐400 is described. The use of PEG‐400 as the reaction medium and avoiding the use of any catalyst makes the process environmentally benign. Seven new compounds are reported.
A novel approach towards the synthesis of tricyclic systems based on pyridine, pyran, thiopyran, azepine, oxepin, thiepin, and pyrimidine rings under different solvent conditions
作者:Anand Sachar、Poonam Gupta、Shallu Gupta、R. L. Sharma
DOI:10.1139/v10-015
日期:2010.5
Synthesis of some oxygen, nitrogen, and sulfur based condensed heterocycles by the condensation of dimedone with aromatic monoaldehyde under different solvent conditions has been achieved.