utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensationbetween poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product,
Synthesis and biological evaluation of a novel series of 1,5-benzothiazepine derivatives as potential antimicrobial agents
作者:Lanzhi Wang、Ping Zhang、Xuemei Zhang、Yonghong Zhang、Yuan Li、Yongxiang Wang
DOI:10.1016/j.ejmech.2008.12.021
日期:2009.7
Two series of novel 1,5-benzothiazepine derivatives (23 compounds) were efficiently synthesized and evaluated for antibacterial and antifungal activities. The results indicated that the compounds possessed a broad spectrum of activity against the tested microorganisms and showed higher activity against fungi than bacteria. Compound 2e exhibited the greatest antimicrobial activity. Preliminary study
A new protocol for the Knoevenagel condensation between β-diketones and aliphatic and aromatic aldehydes promoted by Mg(ClO4)2 under mild conditions is reported.
Aldol Condensation of β-Diketones and β-Ketoesters with Aldehydes Catalyzed by Samarium (III) Iodide
作者:Weiliang Bao、Yongmin Zhang、Jingang Wang
DOI:10.1080/00397919608004607
日期:1996.8
Abstract Catalyzed by SmI3 β-diketones and β-ketoesters condense with aldehydes to give benzylidene substituted β-diketones and β-ketoesters at room temperatures in fair yields.
A chiral, ammoniumylide based access to tetrasubstituted 2,3-dihydrofurans starting from readily available benzylidene dicarbonyls and bromo acetophenones has been developed. The products are obtained in moderate to good yields with excellent diasteroselectivity and good to excellent enantioselectivity (up to 99:1 e.r.). The employed chiral amine can be recovered in near quantitative yield. The transformation