Efficient and recyclable solid acid-catalyzed alkylation of active methylene compound via oxonium intermediate for atom economical synthesis of organic compounds
作者:Dhanaji R. Naikwadi、Balasaheb D. Bankar、Krishnan Ravi、Ankush V. Biradar
DOI:10.1007/s11164-021-04499-3
日期:2021.9
enol ethers and aryl acetals through oxonium intermediate under solvent-free conditions using heterogeneous solid acid catalysts. Among studied solid acid catalysts, Amberlyst-15 gave excellent yields (35–85%) of alkylated products. The catalyst showed broader substrate scope, and a recyclable catalytic cost-efficient approach of the alkylation was examined on the different types of cyclic enol ethers
Alumina supported potassium fluoride promoted reaction of nitroalkanes with electrophilic alkenes : synthesis of 4,5-dihydro furans and isoxazoline n-oxides
作者:Jean Marie Mélot、Francoise Texier-Boullet、André Foucaud
DOI:10.1016/s0040-4020(01)81729-4
日期:1988.1
The reaction of secondary nitro alkanes 1 with α,β-unsaturated ketones 2 in the presence of alumina-supported potassiumfluoride in acetonitrile gave 4,5-dihydrofurans 3 in high yields ; 1-nitropropane reacted with 2 to give a mixture of 4,5-dihydrofurans and furans. Nitroalkenes 17 reacted with nitroalkanes to give isoxazoline N-oxides 18 and 19 in good overall yields.
An Efficient Method for the Selective Iodination of α,β-Unsaturated Ketones
作者:Anxin Wu、Zihua Wang、Guodong Yin、Jing Qin、Meng Gao、Liping Cao
DOI:10.1055/s-0028-1083200
日期:2008.11
An efficient approach to α,β-unsaturated a'-iodo ketones directly from α,β-unsaturatedketones by selective iodination at the a'-position, without effect on the doublebond and the activated benzene ring, in the presence of copper(II) oxide/iodine is described. The present method has the advantages of high yields, short reaction times, inexpensive reagents, mild reaction conditions, ease of manipulation
Stereoselective Synthesis of α-Ylidene-β-dicarbonyl Compounds: A Mild PhI(OAc)<sub>2</sub>-mediated Dehydrogenation Process
作者:Liyan Fan、Wen Chen、Kunshan Tang、Dongbei Wu
DOI:10.1246/cl.2012.940
日期:2012.9.5
PhI(OAc)2-mediated dehydrogenation of α-alkyl-β-dicarbonyl compound has been developed to afford α-ylidene-β-dicarbonyl compounds with high stereoselectivity under mild conditions. This process provides a complementary entry to stereoselectivity for the Knoevenagel reaction.
Precise control of the chemoselectivity of the halogenation of a substrate equipped with multiple nucleophilic sites is highly demanding and challenging. Most reported chlorinations of methyl ketones show poor compatibility or even exclusive selectivity toward electron-rich arene, olefin, and alkyne residues. This is attributed to the direct or in situ employment of electrophilic Cl2/Cl+ species. Here