Strontium triflate catalyzed one-pot condensation of β-naphthol, aldehydes and cyclic 1,3-dicarbonyl compounds

Surfactant catalyzed convenient and greener synthesis of tetrahydrobenzo[a]xanthene-11-ones at ambient temperature

An efficient and greener protocol for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one using tetradecyltrimethylammonium bromide (TTAB) at room temperature in water is described.

Efficient One-Pot Synthesis of 12-Aryl-8,9,10,12-Tetrahydrobenzo[a]Xanthen-11-one Derivatives Using NaHSO4 as Catalyst in Ionic Liquid

A series of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives were synthesized via the three-component coupling from aromatic aldehydes, 2-naphthol and 5,5–dimethylcyclohexane -1,3-dione catalyzed by NaHSO4 in ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). The reaction proceeded with good yields under short reaction time. The NaHSO4 was not expensive and the ionic liquid could be reused. The proposed method is efficient and environmentally friendly.

Proline triflate catalysed Diels–Alder reaction in the synthesis of tetrahydroquinoline derivatives

Proline triflate was found to catalyse efficiently the one-pot synthesis of 2H-pyranotetrahydroquinolines from aryl imines, and 3,4-dihydro-2 H-pyran with high stereoselectivity. The aryl imines were formed in situ from aromatic amines and arylaldehydes.

The Cyclisation of 2′-aminochalcones using Silica-Supported Yb(OTf)3 under Solvent-free Conditions

Silica-supported Yb(OTf)3 is utilised as a catalyst for the synthesis of 2-substituted dihydroquinolinones from 2′-amino chalcones in good yields. The catalyst is easily prepared and is active under solvent-free conditions and environmentally friendly conditions.