title: CaCl(2) as a bifunctional reusable catalyst: diversity-oriented synthesis of 4H-pyran library under ultrasonic irradiation.
abstract: CaCl(2) is applied as an efficient reusable and eco-friendly bifunctional catalyst for the one-pot three-component synthesis of 4H-pyrans under ultrasonic irradiation. A broad range of substrates including the aromatic and heteroaromatic aldehydes, indoline-2,3-dione (isatin) derivatives, acenaphthylene-1,2-dione (acenaphthenequinone) and 2, 2-dihydroxy-2H-indene-1,3-dione (ninhydrin) were condensed with carbonyl compounds possessing a reactive α-methylene group and alkylmalonates. All reactions are completed in short times, and the products are obtained in good to excellent yields. The catalyst could be recycled and reused several times without any loss of efficiency.
authors.affiliation: Department of Applied Chemistry, Islamic Azad University, Shiraz Branch, Shiraz, Iran. hrs@iaushiraz.net
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Safaei
authors.forename: Mohsen
authors.initials: M
authors.lastname: Shekouhy
authors.forename: Athar
authors.initials: A
authors.lastname: Shirinfeshan
authors.forename: Sudabeh
authors.initials: S
authors.lastname: Rahmanpur
mesh_terms: D000073:Acenaphthenes / Q000138:chemical synthesis; D000447:Aldehydes / Q000138:chemical synthesis; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D002122:Calcium Chloride / Q000737:chemistry*; D002384:Catalysis; D007510:Isatin / Q000138:chemical synthesis; D015394:Molecular Structure; D009555:Ninhydrin / Q000138:chemical synthesis; D011714:Pyrans / Q000138:chemical synthesis*; D011827:Radiation; D014465:Ultrasonics
chemical_list: D000073:Acenaphthenes; D000447:Aldehydes; D000900:Anti-Bacterial Agents; D011714:Pyrans; C023722:acenaphthenequinone; D007510:Isatin; D009555:Ninhydrin; D002122:Calcium Chloride